Ubuntu Manpage: ovs-vswitchd.conf.db - Open

Provided by: openvswitch-switch_3.2.2-0ubuntu0.23.10.1_amd64

NAME

ovs-vswitchd.conf.db - Open_vSwitch database schema

A database with this schema holds the configuration for one Open vSwitch daemon. The top-
level configuration for the daemon is the Open_vSwitch table, which must have exactly one
record. Records in other tables are significant only when they can be reached directly or
indirectly from the Open_vSwitch table. Records that are not reachable from the
Open_vSwitch table are automatically deleted from the database, except for records in a
few distinguished ``root set’’ tables.

Common Columns
Most tables contain two special columns, named other_config and external_ids. These
columns have the same form and purpose each place that they appear, so we describe them
here to save space later.

other_config: map of string-string pairs
Key-value pairs for configuring rarely used features. Supported keys, along
with the forms taken by their values, are documented individually for each
table.

A few tables do not have other_config columns because no key-value pairs
have yet been defined for them.

external_ids: map of string-string pairs
Key-value pairs for use by external frameworks that integrate with Open
vSwitch, rather than by Open vSwitch itself. System integrators should
either use the Open vSwitch development mailing list to coordinate on common
key-value definitions, or choose key names that are likely to be unique. In
some cases, where key-value pairs have been defined that are likely to be
widely useful, they are documented individually for each table.

TABLE SUMMARY

       The following list summarizes the purpose of  each  of  the  tables  in  the  Open_vSwitch
       database.  Each table is described in more detail on a later page.

       Table     Purpose
       Open_vSwitch
                 Open vSwitch configuration.
       Bridge    Bridge configuration.
       Port      Port configuration.
       Interface One physical network device in a Port.
       Flow_Table
                 OpenFlow table configuration
       QoS       Quality of Service configuration
       Queue     QoS output queue.
       Mirror    Port mirroring.
       Controller
                 OpenFlow controller configuration.
       Manager   OVSDB management connection.
       NetFlow   NetFlow configuration.
       Datapath  Datapath configuration.
       CT_Zone   CT_Zone configuration.
       CT_Timeout_Policy
                 CT_Timeout_Policy configuration.
       SSL       SSL configuration.
       sFlow     sFlow configuration.
       IPFIX     IPFIX configuration.
       Flow_Sample_Collector_Set
                 Flow_Sample_Collector_Set configuration.
       AutoAttach
                 AutoAttach configuration.

Open_vSwitch TABLE

Configuration for an Open vSwitch daemon. There must be exactly one record in the
Open_vSwitch table.

Summary:
Configuration:
datapaths map of string-Datapath pairs
bridges set of Bridges
ssl optional SSL
external_ids : system-id optional string
external_ids : hostname optional string
external_ids : rundir optional string
other_config : stats-update-interval
optional string, containing an integer, at least 5,000
other_config : flow-restore-wait
optional string, either true or false
other_config : flow-limit optional string, containing an integer, at least 0
other_config : max-idle optional string, containing an integer, at least 500
other_config : max-revalidator
optional string, containing an integer, at least 100
other_config : min-revalidate-pps
optional string, containing an integer, at least 0
other_config : offloaded-stats-delay
optional string, containing an integer, at least 0
other_config : hw-offload optional string, either true or false
other_config : n-offload-threads
optional string, containing an integer, in range 1 to 10
other_config : tc-policy optional string, one of none, skip_hw, or skip_sw
other_config : dpdk-init optional string, one of false, true, or try
other_config : dpdk-lcore-mask
optional string, containing an integer, at least 1
other_config : pmd-cpu-mask
optional string
other_config : dpdk-alloc-mem
optional string, containing an integer, at least 0
other_config : dpdk-socket-mem
optional string
other_config : dpdk-socket-limit
optional string
other_config : dpdk-hugepage-dir
optional string
other_config : dpdk-extra optional string
other_config : vhost-sock-dir
optional string
other_config : vhost-iommu-support
optional string, either true or false
other_config : vhost-postcopy-support
optional string, either true or false
other_config : per-port-memory
optional string, either true or false
other_config : shared-mempool-config
optional string
other_config : tx-flush-interval
optional string, containing an integer, in range 0 to
1,000,000
other_config : pmd-perf-metrics
optional string, either true or false
other_config : smc-enable optional string, either true or false
other_config : pmd-rxq-assign
optional string, one of cycles, group, or roundrobin
other_config : pmd-rxq-isolate
optional string, either true or false
other_config : n-handler-threads
optional string, containing an integer, at least 1
other_config : n-revalidator-threads
optional string, containing an integer, at least 1
other_config : emc-insert-inv-prob
optional string, containing an integer, in range 0 to
4,294,967,295
other_config : vlan-limit optional string, containing an integer, at least 0
other_config : bundle-idle-timeout
optional string, containing an integer, at least 1
other_config : offload-rebalance
optional string, either true or false
other_config : pmd-auto-lb optional string, either true or false
other_config : pmd-auto-lb-rebal-interval
optional string, containing an integer, in range 0 to 20,000
other_config : pmd-auto-lb-load-threshold
optional string, containing an integer, in range 0 to 100
other_config : pmd-auto-lb-improvement-threshold
optional string, containing an integer, in range 0 to 100
other_config : pmd-sleep-max
optional string, containing an integer, in range 0 to 10,000
other_config : userspace-tso-enable
optional string, either true or false
Status:
next_cfg integer
cur_cfg integer
dpdk_initialized boolean
Statistics:
other_config : enable-statistics
optional string, either true or false
statistics : cpu optional string, containing an integer, at least 1
statistics : load_average
optional string
statistics : memory optional string
statistics : process_NAME
optional string
statistics : file_systems
optional string
Version Reporting:
ovs_version optional string
db_version optional string
system_type optional string
system_version optional string
dpdk_version optional string
Capabilities:
datapath_types set of strings
iface_types set of strings
Database Configuration:
manager_options set of Managers
IPsec:
other_config : private_key optional string
other_config : certificate optional string
other_config : ca_cert optional string
Plaintext Tunnel Policy:
other_config : ipsec_skb_mark
optional string
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs

Details:
Configuration:

datapaths: map of string-Datapath pairs
Map of datapath types to datapaths. The datapath_type column of the Bridge table is
used as a key for this map. The value points to a row in the Datapath table.

bridges: set of Bridges
Set of bridges managed by the daemon.

ssl: optional SSL
SSL used globally by the daemon.

external_ids : system-id: optional string
A unique identifier for the Open vSwitch’s physical host. The form of the
identifier depends on the type of the host.

external_ids : hostname: optional string
The hostname for the host running Open vSwitch. This is a fully qualified domain
name since version 2.6.2.

external_ids : rundir: optional string
In Open vSwitch 2.8 and later, the run directory of the running Open vSwitch
daemon. This directory is used for runtime state such as control and management
sockets. The value of other_config:vhost-sock-dir is relative to this directory.

other_config : stats-update-interval: optional string, containing an integer, at least
5,000
Interval for updating statistics to the database, in milliseconds. This option will
affect the update of the statistics column in the following tables: Port, Interface
, Mirror.

Default value is 5000 ms.

Getting statistics more frequently can be achieved via OpenFlow.

other_config : flow-restore-wait: optional string, either true or false
When ovs-vswitchd starts up, it has an empty flow table and therefore it handles
all arriving packets in its default fashion according to its configuration, by
dropping them or sending them to an OpenFlow controller or switching them as a
standalone switch. This behavior is ordinarily desirable. However, if ovs-vswitchd
is restarting as part of a ``hot-upgrade,’’ then this leads to a relatively long
period during which packets are mishandled.

This option allows for improvement. When ovs-vswitchd starts with this value set as
true, it will neither flush or expire previously set datapath flows nor will it
send and receive any packets to or from the datapath. When this value is later set
to false, ovs-vswitchd will start receiving packets from the datapath and re-setup
the flows.

Additionally, ovs-vswitchd is prevented from connecting to controllers when this
value is set to true. This prevents controllers from making changes to the flow
table in the middle of flow restoration, which could result in undesirable
intermediate states. Once this value has been set to false and the desired flow
state has been restored, ovs-vswitchd will be able to reconnect to controllers and
process any new flow table modifications.

Thus, with this option, the procedure for a hot-upgrade of ovs-vswitchd becomes
roughly the following:

1. Stop ovs-vswitchd.

2. Set other_config:flow-restore-wait to true.

3. Start ovs-vswitchd.

4. Use ovs-ofctl (or some other program, such as an OpenFlow controller) to
restore the OpenFlow flow table to the desired state.

5. Set other_config:flow-restore-wait to false (or remove it entirely from the
database).

The ovs-ctl’s ``restart’’ and ``force-reload-kmod’’ functions use the above config
option during hot upgrades.

other_config : flow-limit: optional string, containing an integer, at least 0
The maximum number of flows allowed in the datapath flow table. Internally OVS will
choose a flow limit which will likely be lower than this number, based on real time
network conditions. Tweaking this value is discouraged unless you know exactly what
you’re doing.

The default is 200000.

other_config : max-idle: optional string, containing an integer, at least 500
The maximum time (in ms) that idle flows will remain cached in the datapath.
Internally OVS will check the validity and activity for datapath flows regularly
and may expire flows quicker than this number, based on real time network
conditions. Tweaking this value is discouraged unless you know exactly what you’re
doing.

The default is 10000.

other_config : max-revalidator: optional string, containing an integer, at least 100
The maximum time (in ms) that revalidator threads will wait before executing flow
revalidation. Note that this is maximum allowed value. Actual timeout used by OVS
is minimum of max-idle and max-revalidator values. Tweaking this value is
discouraged unless you know exactly what you’re doing.

The default is 500.

other_config : min-revalidate-pps: optional string, containing an integer, at least 0
Set minimum pps that flow must have in order to be revalidated when revalidation
duration exceeds half of max-revalidator config variable. Setting to 0 means always
revalidate flows regardless of pps.

The default is 5.

other_config : offloaded-stats-delay: optional string, containing an integer, at least 0
Set worst case delay (in ms) it might take before statistics of offloaded flows are
updated. Offloaded flows younger than this delay will always be revalidated
regardless of other_config:min-revalidate-pps.

The default is 2000.

other_config : hw-offload: optional string, either true or false
Set this value to true to enable netdev flow offload.

The default value is false. Changing this value requires restarting the daemon

Currently Open vSwitch supports hardware offloading on Linux systems. On other
systems, this value is ignored. This functionality is considered ’experimental’.
Depending on which OpenFlow matches and actions are configured, which kernel
version is used, and what hardware is available, Open vSwitch may not be able to
offload functionality to hardware.

In order to dump HW offloaded flows use ovs-appctl dpctl/dump-flows, ovs-dpctl
doesn’t support this functionality. See ovs-vswitchd(8) for details.

other_config : n-offload-threads: optional string, containing an integer, in range 1 to 10
Set this value to the number of threads created to manage hardware offloads.

The default value is 1. Changing this value requires restarting the daemon.

This is only relevant for userspace datapath and only if other_config:hw-offload is
enabled.

other_config : tc-policy: optional string, one of none, skip_hw, or skip_sw
Specified the policy used with HW offloading. Options:

none Add software rule and offload rule to HW.

skip_sw
Offload rule to HW only.

skip_hw
Add software rule without offloading rule to HW.

This is only relevant if other_config:hw-offload is enabled.

The default value is none.

other_config : dpdk-init: optional string, one of false, true, or try
Set this value to true or try to enable runtime support for DPDK ports. The vswitch
must have compile-time support for DPDK as well.

A value of true will cause the ovs-vswitchd process to abort if DPDK cannot be
initialized. A value of try will allow the ovs-vswitchd process to continue running
even if DPDK cannot be initialized.

The default value is false. Changing this value requires restarting the daemon

If this value is false at startup, any dpdk ports which are configured in the
bridge will fail due to memory errors.

other_config : dpdk-lcore-mask: optional string, containing an integer, at least 1
Specifies the CPU cores where dpdk lcore threads should be spawned. The DPDK lcore
threads are used for DPDK library tasks, such as library internal message
processing, logging, etc. Value should be in the form of a hex string (so ’0x123’)
similar to the ’taskset’ mask input.

The lowest order bit corresponds to the first CPU core. A set bit means the
corresponding core is available and an lcore thread will be created and pinned to
it. If the input does not cover all cores, those uncovered cores are considered not
set.

For performance reasons, it is best to set this to a single core on the system,
rather than allow lcore threads to float.

If not specified, the value will be determined by choosing the lowest CPU core from
initial cpu affinity list. Otherwise, the value will be passed directly to the DPDK
library.

other_config : pmd-cpu-mask: optional string
Specifies CPU mask for setting the cpu affinity of PMD (Poll Mode Driver) threads.
Value should be in the form of hex string, similar to the dpdk EAL ’-c COREMASK’
option input or the ’taskset’ mask input.

The lowest order bit corresponds to the first CPU core. A set bit means the
corresponding core is available and a pmd thread will be created and pinned to it.
If the input does not cover all cores, those uncovered cores are considered not
set.

If not specified, one pmd thread will be created for each numa node and pinned to
any available core on the numa node by default.

other_config : dpdk-alloc-mem: optional string, containing an integer, at least 0
Specifies the amount of memory to preallocate from the hugepage pool, regardless of
socket. It is recommended that dpdk-socket-mem is used instead.

other_config : dpdk-socket-mem: optional string
Specifies the amount of memory to preallocate from the hugepage pool, on a per-
socket basis.

The specifier is a comma-separated string, in ascending order of CPU socket. E.g.
On a four socket system 1024,0,2048 would set socket 0 to preallocate 1024MB,
socket 1 to preallocate 0MB, socket 2 to preallocate 2048MB and socket 3 (no value
given) to preallocate 0MB.

If other_config:dpdk-socket-mem and other_config:dpdk-alloc-mem are not specified,
neither will be used and there will be no default value for each numa node. DPDK
defaults will be used instead. If other_config:dpdk-socket-mem and
other_config:dpdk-alloc-mem are specified at the same time, other_config:dpdk-
socket-mem will be used as default. Changing this value requires restarting the
daemon.

other_config : dpdk-socket-limit: optional string
Limits the maximum amount of memory that can be used from the hugepage pool, on a
per-socket basis.

The specifier is a comma-separated list of memory limits per socket. 0 will disable
the limit for a particular socket.

If not specified, OVS will not configure limits by default. Changing this value
requires restarting the daemon.

other_config : dpdk-hugepage-dir: optional string
Specifies the path to the hugetlbfs mount point.

If not specified, this will be guessed by the DPDK library (default is
/dev/hugepages). Changing this value requires restarting the daemon.

other_config : dpdk-extra: optional string
Specifies additional eal command line arguments for DPDK.

The default is empty. Changing this value requires restarting the daemon

other_config : vhost-sock-dir: optional string
Specifies a relative path from external_ids:rundir to the vhost-user unix domain
socket files. If this value is unset, the sockets are put directly in
external_ids:rundir.

Changing this value requires restarting the daemon.

other_config : vhost-iommu-support: optional string, either true or false
vHost IOMMU is a security feature, which restricts the vhost memory that a virtio
device may access. vHost IOMMU support is disabled by default, due to a bug in QEMU
implementations of the vhost REPLY_ACK protocol, (on which vHost IOMMU relies)
prior to v2.9.1. Setting this value to true enables vHost IOMMU support for vHost
User Client ports in OvS-DPDK, starting from DPDK v17.11.

Changing this value requires restarting the daemon.

other_config : vhost-postcopy-support: optional string, either true or false
vHost post-copy is a feature which allows switching live migration of VM attached
to dpdkvhostuserclient port to post-copy mode if default pre-copy migration can not
be converged or takes too long to converge. Setting this value to true enables
vHost post-copy support for all dpdkvhostuserclient ports. Available starting from
DPDK v18.11 and QEMU 2.12.

Changing this value requires restarting the daemon.

other_config : per-port-memory: optional string, either true or false
By default OVS DPDK uses a shared memory model wherein devices that have the same
MTU and socket values can share the same mempool. Setting this value to true
changes this behaviour. Per port memory allow DPDK devices to use private memory
per device. This can provide greater transparency as regards memory usage but
potentially at the cost of greater memory requirements.

Changing this value requires restarting the daemon if dpdk-init has already been
set to true.

other_config : shared-mempool-config: optional string
Specifies dpdk shared mempool config.

Value should be set in the following form:

other_config:shared-mempool-config=< user-shared-mempool-mtu-list>

where

• <user-shared-mempool-mtu-list> ::= NULL | <non-empty-list>

• <non-empty-list> ::= <user-mtus> | <user-mtus> , <non-empty-list>

• <user-mtus> ::= <mtu-all-socket> | <mtu-socket-pair>

• <mtu-all-socket> ::= <mtu>

• <mtu-socket-pair> ::= <mtu> : <socket-id>

Changing this value requires restarting the daemon if dpdk-init has already been
set to true.

other_config : tx-flush-interval: optional string, containing an integer, in range 0 to
1,000,000
Specifies the time in microseconds that a packet can wait in output batch for
sending i.e. amount of time that packet can spend in an intermediate output queue
before sending to netdev. This option can be used to configure balance between
throughput and latency. Lower values decreases latency while higher values may be
useful to achieve higher performance.

Defaults to 0 i.e. instant packet sending (latency optimized).

other_config : pmd-perf-metrics: optional string, either true or false
Enables recording of detailed PMD performance metrics for analysis and trouble-
shooting. This can have a performance impact in the order of 1%.

Defaults to false but can be changed at any time.

other_config : smc-enable: optional string, either true or false
Signature match cache or SMC is a cache between EMC and megaflow cache. It does not
store the full key of the flow, so it is more memory efficient comparing to EMC
cache. SMC is especially useful when flow count is larger than EMC capacity.

Defaults to false but can be changed at any time.

other_config : pmd-rxq-assign: optional string, one of cycles, group, or roundrobin
Specifies how RX queues will be automatically assigned to CPU cores. Options:

cycles Rxqs will be sorted by order of measured processing cycles before being
assigned to CPU cores.

roundrobin
Rxqs will be round-robined across CPU cores.

group Rxqs will be sorted by order of measured processing cycles before being
assigned to CPU cores with lowest estimated load.

The default value is cycles.

Changing this value will affect an automatic re-assignment of Rxqs to CPUs. Note:
Rxqs mapped to CPU cores with pmd-rxq-affinity are unaffected.

other_config : pmd-rxq-isolate: optional string, either true or false
Specifies if a CPU core will be isolated after being pinned with an Rx queue.

Set this value to false to non-isolate a CPU core after it is pinned with an Rxq
using pmd-rxq-affinity. This will allow OVS to assign other Rxqs to that CPU core.

The default value is true.

This can only be false when pmd-rxq-assign is set to group.

other_config : n-handler-threads: optional string, containing an integer, at least 1
Attempts to specify the number of threads for software datapaths to use for
handling new flows. Some datapaths may choose to ignore this and it will be set to
a sensible option for the datapath type.

This configuration is per datapath. If you have more than one software datapath
(e.g. some system bridges and some netdev bridges), then the total number of
threads is n-handler-threads times the number of software datapaths.

other_config : n-revalidator-threads: optional string, containing an integer, at least 1
Attempts to specify the number of threads for software datapaths to use for
revalidating flows in the datapath. Some datapaths may choose to ignore this and
will set to a sensible option for the datapath type.

Typically, there is a direct correlation between the number of revalidator threads,
and the number of flows allowed in the datapath. The default is the number of cpu
cores divided by four plus one. If n-handler-threads is set, the default changes to
the number of cpu cores minus the number of handler threads.

other_config : emc-insert-inv-prob: optional string, containing an integer, in range 0 to
4,294,967,295
Specifies the inverse probability (1/emc-insert-inv-prob) of a flow being inserted
into the Exact Match Cache (EMC). On average one in every emc-insert-inv-prob
packets that generate a unique flow will cause an insertion into the EMC. A value
of 1 will result in an insertion for every flow (1/1 = 100%) whereas a value of
zero will result in no insertions and essentially disable the EMC.

Defaults to 100 ie. there is (1/100 =) 1% chance of EMC insertion.

other_config : vlan-limit: optional string, containing an integer, at least 0
Limits the number of VLAN headers that can be matched to the specified number.
Further VLAN headers will be treated as payload, e.g. a packet with more 802.1q
headers will match Ethernet type 0x8100.

Open vSwitch userspace currently supports at most 2 VLANs, and each datapath has
its own limit. If vlan-limit is nonzero, it acts as a further limit.

If this value is absent, the default is currently 1. This maintains backward
compatibility with controllers that were designed for use with Open vSwitch
versions earlier than 2.8, which only supported one VLAN.

other_config : bundle-idle-timeout: optional string, containing an integer, at least 1
The maximum time (in seconds) that idle bundles will wait to be expired since it
was either opened, modified or closed.

OpenFlow specification mandates the timeout to be at least one second. The default
is 10 seconds.

other_config : offload-rebalance: optional string, either true or false
Configures HW offload rebalancing, that allows to dynamically offload and un-
offload flows while an offload-device is out of resources (OOR). This policy allows
flows to be selected for offloading based on the packets-per-second (pps) rate of
flows.

Set this value to true to enable this option.

The default value is false. Changing this value requires restarting the daemon.

This is only relevant if HW offloading is enabled (hw-offload). When this policy is
enabled, it also requires ’tc-policy’ to be set to ’skip_sw’.

other_config : pmd-auto-lb: optional string, either true or false
Configures PMD Auto Load Balancing that allows automatic assignment of RX queues to
PMDs if any of PMDs is overloaded (i.e. a processing cycles > other_config:pmd-
auto-lb-load-threshold).

It uses current scheme of cycle based assignment of RX queues that are not
statically pinned to PMDs.

The default value is false.

Set this value to true to enable this option. It is currently disabled by default
and an experimental feature.

This only comes in effect if cycle based assignment is enabled and there are more
than one non-isolated PMDs present and at least one of it polls more than one
queue.

other_config : pmd-auto-lb-rebal-interval: optional string, containing an integer, in
range 0 to 20,000
The minimum time (in minutes) 2 consecutive PMD Auto Load Balancing iterations.

The default value is 1 min. If configured to 0 then it would be converted to
default value i.e. 1 min

This option can be configured to avoid frequent trigger of auto load balancing of
PMDs. For e.g. set the value (in min) such that it occurs once in few hours or a
day or a week.

other_config : pmd-auto-lb-load-threshold: optional string, containing an integer, in
range 0 to 100
Specifies the minimum PMD thread load threshold (% of used cycles) of any non-
isolated PMD threads when a PMD Auto Load Balance may be triggered.

The default value is 95%.

other_config : pmd-auto-lb-improvement-threshold: optional string, containing an integer,
in range 0 to 100
Specifies the minimum evaluated % improvement in load distribution across the non-
isolated PMD threads that will allow a PMD Auto Load Balance to occur.

Note, setting this parameter to 0 will always allow an auto load balance to occur
regardless of estimated improvement or not.

The default value is 25%.

other_config : pmd-sleep-max: optional string, containing an integer, in range 0 to 10,000
Specifies the maximum sleep time that will be requested in microseconds per
iteration for a PMD thread which has received zero or a small amount of packets
from the Rx queues it is polling.

The actual sleep time requested is based on the load of the Rx queues that the PMD
polls and may be less than the maximum value.

The default value is 0 microseconds, which means that the PMD will not sleep
regardless of the load from the Rx queues that it polls.

The maximum value is 10000 microseconds.

other_config : userspace-tso-enable: optional string, either true or false
Set this value to true to enable userspace support for TCP Segmentation Offloading
(TSO). When it is enabled, the interfaces can provide an oversized TCP segment to
the datapath and the datapath will offload the TCP segmentation and checksum
calculation to the interfaces when necessary.

The default value is false. Changing this value requires restarting the daemon.

The feature only works if Open vSwitch is built with DPDK support.

The feature is considered experimental.

Status:

next_cfg: integer
Sequence number for client to increment. When a client modifies any part of the
database configuration and wishes to wait for Open vSwitch to finish applying the
changes, it may increment this sequence number.

cur_cfg: integer
Sequence number that Open vSwitch sets to the current value of next_cfg after it
finishes applying a set of configuration changes.

dpdk_initialized: boolean
True if other_config:dpdk-init is set to true and the DPDK library is successfully
initialized.

Statistics:

The statistics column contains key-value pairs that report statistics about a system
running an Open vSwitch. These are updated periodically (currently, every 5 seconds). Key-
value pairs that cannot be determined or that do not apply to a platform are omitted.

other_config : enable-statistics: optional string, either true or false
Statistics are disabled by default to avoid overhead in the common case when
statistics gathering is not useful. Set this value to true to enable populating the
statistics column or to false to explicitly disable it.

statistics : cpu: optional string, containing an integer, at least 1
Number of CPU processors, threads, or cores currently online and available to the
operating system on which Open vSwitch is running, as an integer. This may be less
than the number installed, if some are not online or if they are not available to
the operating system.

Open vSwitch userspace processes are not multithreaded, but the Linux kernel-based
datapath is.

statistics : load_average: optional string
A comma-separated list of three floating-point numbers, representing the system
load average over the last 1, 5, and 15 minutes, respectively.

statistics : memory: optional string
A comma-separated list of integers, each of which represents a quantity of memory
in kilobytes that describes the operating system on which Open vSwitch is running.
In respective order, these values are:

1. Total amount of RAM allocated to the OS.

2. RAM allocated to the OS that is in use.

3. RAM that can be flushed out to disk or otherwise discarded if that space is
needed for another purpose. This number is necessarily less than or equal to
the previous value.

4. Total disk space allocated for swap.

5. Swap space currently in use.

On Linux, all five values can be determined and are included. On other operating
systems, only the first two values can be determined, so the list will only have
two values.

statistics : process_NAME: optional string
One such key-value pair, with NAME replaced by a process name, will exist for each
running Open vSwitch daemon process, with name replaced by the daemon’s name (e.g.
process_ovs-vswitchd). The value is a comma-separated list of integers. The
integers represent the following, with memory measured in kilobytes and durations
in milliseconds:

1. The process’s virtual memory size.

2. The process’s resident set size.

3. The amount of user and system CPU time consumed by the process.

4. The number of times that the process has crashed and been automatically
restarted by the monitor.

5. The duration since the process was started.

6. The duration for which the process has been running.

The interpretation of some of these values depends on whether the process was
started with the --monitor. If it was not, then the crash count will always be 0
and the two durations will always be the same. If --monitor was given, then the
crash count may be positive; if it is, the latter duration is the amount of time
since the most recent crash and restart.

There will be one key-value pair for each file in Open vSwitch’s ``run directory’’
(usually /var/run/openvswitch) whose name ends in .pid, whose contents are a
process ID, and which is locked by a running process. The name is taken from the
pidfile’s name.

Currently Open vSwitch is only able to obtain all of the above detail on Linux
systems. On other systems, the same key-value pairs will be present but the values
will always be the empty string.

statistics : file_systems: optional string
A space-separated list of information on local, writable file systems. Each item in
the list describes one file system and consists in turn of a comma-separated list
of the following:

1. Mount point, e.g. / or /var/log. Any spaces or commas in the mount point are
replaced by underscores.

2. Total size, in kilobytes, as an integer.

3. Amount of storage in use, in kilobytes, as an integer.

This key-value pair is omitted if there are no local, writable file systems or if
Open vSwitch cannot obtain the needed information.

Version Reporting:

These columns report the types and versions of the hardware and software running Open
vSwitch. We recommend in general that software should test whether specific features are
supported instead of relying on version number checks. These values are primarily intended
for reporting to human administrators.

ovs_version: optional string
The Open vSwitch version number, e.g. 1.1.0.

db_version: optional string
The database schema version number, e.g. 1.2.3. See ovsdb-tool(1) for an
explanation of the numbering scheme.

The schema version is part of the database schema, so it can also be retrieved by
fetching the schema using the Open vSwitch database protocol.

system_type: optional string
An identifier for the type of system on top of which Open vSwitch runs, e.g. KVM.

System integrators are responsible for choosing and setting an appropriate value
for this column.

system_version: optional string
The version of the system identified by system_type, e.g. 4.18.0-372.19.1.el8_6 on
RHEL 8.6 with kernel 4.18.0-372.19.1.

System integrators are responsible for choosing and setting an appropriate value
for this column.

dpdk_version: optional string
The version of the linked DPDK library.

Capabilities:

These columns report capabilities of the Open vSwitch instance.

datapath_types: set of strings
This column reports the different dpifs registered with the system. These are the
values that this instance supports in the datapath_type column of the Bridge table.

iface_types: set of strings
This column reports the different netdevs registered with the system. These are the
values that this instance supports in the type column of the Interface table.

Database Configuration:

These columns primarily configure the Open vSwitch database (ovsdb-server), not the Open
vSwitch switch (ovs-vswitchd). The OVSDB database also uses the ssl settings.

The Open vSwitch switch does read the database configuration to determine remote IP
addresses to which in-band control should apply.

manager_options: set of Managers
Database clients to which the Open vSwitch database server should connect or to
which it should listen, along with options for how these connections should be
configured. See the Manager table for more information.

For this column to serve its purpose, ovsdb-server must be configured to honor it.
The easiest way to do this is to invoke ovsdb-server with the option
--remote=db:Open_vSwitch,Open_vSwitch,manager_options The startup scripts that
accompany Open vSwitch do this by default.

IPsec:

These settings control the global configuration of IPsec tunnels. The options column of
the Interface table configures IPsec for individual tunnels. The options column also
allows for custom options prefixed with ipsec_ to be passed to the individual connections.

OVS IPsec supports the following three forms of authentication. Currently, all IPsec
tunnels must use the same form:

1. Pre-shared keys: Omit the global settings. On each tunnel, set options:psk.

2. Self-signed certificates: Set the private_key and certificate global settings.
On each tunnel, set options:remote_cert. The remote certificate can be self-
signed.

3. CA-signed certificates: Set all of the global settings. On each tunnel, set
options:remote_name to the common name (CN) of the remote certificate. The
remote certificate must be signed by the CA.

other_config : private_key: optional string
Name of a PEM file containing the private key used as the switch’s identity for
IPsec tunnels.

other_config : certificate: optional string
Name of a PEM file containing a certificate that certifies the switch’s private
key, and identifies a trustworthy switch for IPsec tunnels. The certificate must be
x.509 version 3 and with the string in common name (CN) also set in the subject
alternative name (SAN).

other_config : ca_cert: optional string
Name of a PEM file containing the CA certificate used to verify that a remote
switch of the IPsec tunnel is trustworthy.

Plaintext Tunnel Policy:

When an IPsec tunnel is configured in this database, multiple independent components take
responsibility for implementing it. ovs-vswitchd and its datapath handle packet forwarding
to the tunnel and a separate daemon pushes the tunnel’s IPsec policy configuration to the
kernel or other entity that implements it. There is a race: if the former configuration
completes before the latter, then packets sent by the local host over the tunnel can be
transmitted in plaintext. Using this setting, OVS users can avoid this undesirable
situation.

other_config : ipsec_skb_mark: optional string
This setting takes the form value/mask. If it is specified, then the skb_mark field
in every outgoing tunneled packet sent in plaintext is compared against it and, if
it matches, the packet is dropped. This is a global setting that is applied to
every tunneled packet, regardless of whether IPsec encryption is enabled for the
tunnel, the type of tunnel, or whether OVS is involved.

Example policies:

1/1 Drop all unencrypted tunneled packets in which the least-significant bit of
skb_mark is 1. This would be a useful policy given an OpenFlow flow table
that sets skb_mark to 1 for traffic that should be encrypted. The default
skb_mark is 0, so this would not affect other traffic.

0/1 Drop all unencrypted tunneled packets in which the least-significant bit of
skb_mark is 0. This would be a useful policy if no unencrypted tunneled
traffic should exit the system without being specially permitted by setting
skb_mark to 1.

(empty)
If this setting is empty or unset, then all unencrypted tunneled packets are
transmitted in the usual way.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

other_config: map of string-string pairs

external_ids: map of string-string pairs

Bridge TABLE

Configuration for a bridge within an Open_vSwitch.

A Bridge record represents an Ethernet switch with one or more ``ports,’’ which are the
Port records pointed to by the Bridge’s ports column.

Summary:
Core Features:
name immutable string (must be unique within table)
ports set of Ports
mirrors set of Mirrors
netflow optional NetFlow
sflow optional sFlow
ipfix optional IPFIX
flood_vlans set of up to 4,096 integers, in range 0 to 4,095
auto_attach optional AutoAttach
OpenFlow Configuration:
controller set of Controllers
flow_tables map of integer-Flow_Table pairs, key in range 0 to 254
fail_mode optional string, either secure or standalone
datapath_id optional string
datapath_version string
other_config : datapath-id optional string
other_config : dp-desc optional string
other_config : dp-sn optional string
other_config : disable-in-band
optional string, either true or false
other_config : in-band-queue
optional string, containing an integer, in range 0 to
4,294,967,295
other_config : controller-queue-size
optional string, containing an integer, in range 1 to 512
protocols set of strings, one of OpenFlow10, OpenFlow11, OpenFlow12,
OpenFlow13, OpenFlow14, or OpenFlow15
Spanning Tree Configuration:
STP Configuration:
stp_enable boolean
other_config : stp-system-id
optional string
other_config : stp-priority
optional string, containing an integer, in range 0 to 65,535
other_config : stp-hello-time
optional string, containing an integer, in range 1 to 10
other_config : stp-max-age
optional string, containing an integer, in range 6 to 40
other_config : stp-forward-delay
optional string, containing an integer, in range 4 to 30
other_config : mcast-snooping-aging-time
optional string, containing an integer, at least 1
other_config : mcast-snooping-table-size
optional string, containing an integer, at least 1
other_config : mcast-snooping-disable-flood-unregistered
optional string, either true or false
STP Status:
status : stp_bridge_id optional string
status : stp_designated_root
optional string
status : stp_root_path_cost
optional string
Rapid Spanning Tree:
RSTP Configuration:
rstp_enable boolean
other_config : rstp-address
optional string
other_config : rstp-priority
optional string, containing an integer, in range 0 to 61,440
other_config : rstp-ageing-time
optional string, containing an integer, in range 10 to
1,000,000
other_config : rstp-force-protocol-version
optional string, containing an integer
other_config : rstp-max-age
optional string, containing an integer, in range 6 to 40
other_config : rstp-forward-delay
optional string, containing an integer, in range 4 to 30
other_config : rstp-transmit-hold-count
optional string, containing an integer, in range 1 to 10
RSTP Status:
rstp_status : rstp_bridge_id
optional string
rstp_status : rstp_root_id
optional string
rstp_status : rstp_root_path_cost
optional string, containing an integer, at least 0
rstp_status : rstp_designated_id
optional string
rstp_status : rstp_designated_port_id
optional string
rstp_status : rstp_bridge_port_id
optional string
Multicast Snooping Configuration:
mcast_snooping_enable boolean
Other Features:
datapath_type string
external_ids : bridge-id optional string
other_config : hwaddr optional string
other_config : forward-bpdu
optional string, either true or false
other_config : mac-aging-time
optional string, containing an integer, at least 1
other_config : mac-table-size
optional string, containing an integer, at least 1
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs

Details:
Core Features:

name: immutable string (must be unique within table)
Bridge identifier. Must be unique among the names of ports, interfaces, and bridges
on a host.

The name must be alphanumeric and must not contain forward or backward slashes. The
name of a bridge is also the name of an Interface (and a Port) within the bridge,
so the restrictions on the name column in the Interface table, particularly on
length, also apply to bridge names. Refer to the documentation for Interface names
for details.

ports: set of Ports
Ports included in the bridge.

mirrors: set of Mirrors
Port mirroring configuration.

netflow: optional NetFlow
NetFlow configuration.

sflow: optional sFlow
sFlow(R) configuration.

ipfix: optional IPFIX
IPFIX configuration.

flood_vlans: set of up to 4,096 integers, in range 0 to 4,095
VLAN IDs of VLANs on which MAC address learning should be disabled, so that packets
are flooded instead of being sent to specific ports that are believed to contain
packets’ destination MACs. This should ordinarily be used to disable MAC learning
on VLANs used for mirroring (RSPAN VLANs). It may also be useful for debugging.

SLB bonding (see the bond_mode column in the Port table) is incompatible with
flood_vlans. Consider using another bonding mode or a different type of mirror
instead.

auto_attach: optional AutoAttach
Auto Attach configuration.

OpenFlow Configuration:

controller: set of Controllers
OpenFlow controller set. If unset, then no OpenFlow controllers will be used.

If there are primary controllers, removing all of them clears the OpenFlow flow
tables, group table, and meter table. If there are no primary controllers, adding
one also clears these tables. Other changes to the set of controllers, such as
adding or removing a service controller, adding another primary controller to
supplement an existing primary controller, or removing only one of two primary
controllers, have no effect on these tables.

flow_tables: map of integer-Flow_Table pairs, key in range 0 to 254
Configuration for OpenFlow tables. Each pair maps from an OpenFlow table ID to
configuration for that table.

fail_mode: optional string, either secure or standalone
When a controller is configured, it is, ordinarily, responsible for setting up all
flows on the switch. Thus, if the connection to the controller fails, no new
network connections can be set up. If the connection to the controller stays down
long enough, no packets can pass through the switch at all. This setting determines
the switch’s response to such a situation. It may be set to one of the following:

standalone
If no message is received from the controller for three times the inactivity
probe interval (see inactivity_probe), then Open vSwitch will take over
responsibility for setting up flows. In this mode, Open vSwitch causes the
bridge to act like an ordinary MAC-learning switch. Open vSwitch will
continue to retry connecting to the controller in the background and, when
the connection succeeds, it will discontinue its standalone behavior.

secure Open vSwitch will not set up flows on its own when the controller connection
fails or when no controllers are defined. The bridge will continue to retry
connecting to any defined controllers forever.

The default is standalone if the value is unset, but future versions of Open
vSwitch may change the default.

The standalone mode can create forwarding loops on a bridge that has more than one
uplink port unless STP is enabled. To avoid loops on such a bridge, configure
secure mode or enable STP (see stp_enable).

The fail_mode setting applies only to primary controllers. When more than one
primary controller is configured, fail_mode is considered only when none of the
configured controllers can be contacted.

Changing fail_mode when no primary controllers are configured clears the OpenFlow
flow tables, group table, and meter table.

datapath_id: optional string
Reports the OpenFlow datapath ID in use. Exactly 16 hex digits. (Setting this
column has no useful effect. Set other-config:datapath-id instead.)

datapath_version: string
Reports the datapath version. This column is maintained for backwards
compatibility. The preferred locatation is the datapath_id column of the Datapath
table. The full documentation for this column is there.

other_config : datapath-id: optional string
Overrides the default OpenFlow datapath ID, setting it to the specified value
specified in hex. The value must either have a 0x prefix or be exactly 16 hex
digits long. May not be all-zero.

other_config : dp-desc: optional string
Human readable description of datapath. It is a maximum 256 byte-long free-form
string to describe the datapath for debugging purposes, e.g. switch3 in room 3120.
The value is returned by the switch as a part of reply to OFPMP_DESC request
(ofp_desc). The OpenFlow specification (e.g. 1.3.5) describes the ofp_desc
structure to contaion "NULL terminated ASCII strings". For the compatibility
reasons no more than 255 ASCII characters should be used.

other_config : dp-sn: optional string
Serial number. It is a maximum 32 byte-long free-form string to provide an
additional switch identification. The value is returned by the switch as a part of
reply to OFPMP_DESC request (ofp_desc). Same as mentioned in the description of
other-config:dp-desc, the string should be no more than 31 ASCII characters for the
compatibility.

other_config : disable-in-band: optional string, either true or false
If set to true, disable in-band control on the bridge regardless of controller and
manager settings.

other_config : in-band-queue: optional string, containing an integer, in range 0 to
4,294,967,295
A queue ID as a nonnegative integer. This sets the OpenFlow queue ID that will be
used by flows set up by in-band control on this bridge. If unset, or if the port
used by an in-band control flow does not have QoS configured, or if the port does
not have a queue with the specified ID, the default queue is used instead.

other_config : controller-queue-size: optional string, containing an integer, in range 1
to 512
This sets the maximum size of the queue of packets that need to be sent to the
OpenFlow management controller. The value must be less than 512. If not specified
the queue size is limited to 100 packets by default. Note: increasing the queue
size might have a negative impact on latency.

protocols: set of strings, one of OpenFlow10, OpenFlow11, OpenFlow12, OpenFlow13,
OpenFlow14, or OpenFlow15
List of OpenFlow protocols that may be used when negotiating a connection with a
controller. OpenFlow 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5 are enabled by default if
this column is empty.

Spanning Tree Configuration:

The IEEE 802.1D Spanning Tree Protocol (STP) is a network protocol that ensures loop-free
topologies. It allows redundant links to be included in the network to provide automatic
backup paths if the active links fails.

These settings configure the slower-to-converge but still widely supported version of
Spanning Tree Protocol, sometimes known as 802.1D-1998. Open vSwitch also supports the
newer Rapid Spanning Tree Protocol (RSTP), documented later in the section titled Rapid
Spanning Tree Configuration.

STP Configuration:

stp_enable: boolean
Enable spanning tree on the bridge. By default, STP is disabled on bridges. Bond,
internal, and mirror ports are not supported and will not participate in the
spanning tree.

STP and RSTP are mutually exclusive. If both are enabled, RSTP will be used.

other_config : stp-system-id: optional string
The bridge’s STP identifier (the lower 48 bits of the bridge-id) in the form
xx:xx:xx:xx:xx:xx. By default, the identifier is the MAC address of the bridge.

other_config : stp-priority: optional string, containing an integer, in range 0 to 65,535
The bridge’s relative priority value for determining the root bridge (the upper 16
bits of the bridge-id). A bridge with the lowest bridge-id is elected the root. By
default, the priority is 0x8000.

other_config : stp-hello-time: optional string, containing an integer, in range 1 to 10
The interval between transmissions of hello messages by designated ports, in
seconds. By default the hello interval is 2 seconds.

other_config : stp-max-age: optional string, containing an integer, in range 6 to 40
The maximum age of the information transmitted by the bridge when it is the root
bridge, in seconds. By default, the maximum age is 20 seconds.

other_config : stp-forward-delay: optional string, containing an integer, in range 4 to 30
The delay to wait between transitioning root and designated ports to forwarding, in
seconds. By default, the forwarding delay is 15 seconds.

other_config : mcast-snooping-aging-time: optional string, containing an integer, at least
1
The maximum number of seconds to retain a multicast snooping entry for which no
packets have been seen. The default is currently 300 seconds (5 minutes). The
value, if specified, is forced into a reasonable range, currently 15 to 3600
seconds.

other_config : mcast-snooping-table-size: optional string, containing an integer, at least
1
The maximum number of multicast snooping addresses to learn. The default is
currently 2048. The value, if specified, is forced into a reasonable range,
currently 10 to 1,000,000.

other_config : mcast-snooping-disable-flood-unregistered: optional string, either true or
false
If set to false, unregistered multicast packets are forwarded to all ports. If set
to true, unregistered multicast packets are forwarded to ports connected to
multicast routers.

STP Status:

These key-value pairs report the status of 802.1D-1998. They are present only if STP is
enabled (via the stp_enable column).

status : stp_bridge_id: optional string
The bridge ID used in spanning tree advertisements, in the form xxxx.yyyyyyyyyyyy
where the xs are the STP priority, the ys are the STP system ID, and each x and y
is a hex digit.

status : stp_designated_root: optional string
The designated root for this spanning tree, in the same form as
status:stp_bridge_id. If this bridge is the root, this will have the same value as
status:stp_bridge_id, otherwise it will differ.

status : stp_root_path_cost: optional string
The path cost of reaching the designated bridge. A lower number is better. The
value is 0 if this bridge is the root, otherwise it is higher.

Rapid Spanning Tree:

Rapid Spanning Tree Protocol (RSTP), like STP, is a network protocol that ensures loop-
free topologies. RSTP superseded STP with the publication of 802.1D-2004. Compared to STP,
RSTP converges more quickly and recovers more quickly from failures.

RSTP Configuration:

rstp_enable: boolean
Enable Rapid Spanning Tree on the bridge. By default, RSTP is disabled on bridges.
Bond, internal, and mirror ports are not supported and will not participate in the
spanning tree.

STP and RSTP are mutually exclusive. If both are enabled, RSTP will be used.

other_config : rstp-address: optional string
The bridge’s RSTP address (the lower 48 bits of the bridge-id) in the form
xx:xx:xx:xx:xx:xx. By default, the address is the MAC address of the bridge.

other_config : rstp-priority: optional string, containing an integer, in range 0 to 61,440
The bridge’s relative priority value for determining the root bridge (the upper 16
bits of the bridge-id). A bridge with the lowest bridge-id is elected the root. By
default, the priority is 0x8000 (32768). This value needs to be a multiple of 4096,
otherwise it’s rounded to the nearest inferior one.

other_config : rstp-ageing-time: optional string, containing an integer, in range 10 to
1,000,000
The Ageing Time parameter for the Bridge. The default value is 300 seconds.

other_config : rstp-force-protocol-version: optional string, containing an integer
The Force Protocol Version parameter for the Bridge. This can take the value 0 (STP
Compatibility mode) or 2 (the default, normal operation).

other_config : rstp-max-age: optional string, containing an integer, in range 6 to 40
The maximum age of the information transmitted by the Bridge when it is the Root
Bridge. The default value is 20.

other_config : rstp-forward-delay: optional string, containing an integer, in range 4 to
30
The delay used by STP Bridges to transition Root and Designated Ports to
Forwarding. The default value is 15.

other_config : rstp-transmit-hold-count: optional string, containing an integer, in range
1 to 10
The Transmit Hold Count used by the Port Transmit state machine to limit
transmission rate. The default value is 6.

RSTP Status:

These key-value pairs report the status of 802.1D-2004. They are present only if RSTP is
enabled (via the rstp_enable column).

rstp_status : rstp_bridge_id: optional string
The bridge ID used in rapid spanning tree advertisements, in the form
x.yyy.zzzzzzzzzzzz where x is the RSTP priority, the ys are a locally assigned
system ID extension, the zs are the STP system ID, and each x, y, or z is a hex
digit.

rstp_status : rstp_root_id: optional string
The root of this spanning tree, in the same form as rstp_status:rstp_bridge_id. If
this bridge is the root, this will have the same value as
rstp_status:rstp_bridge_id, otherwise it will differ.

rstp_status : rstp_root_path_cost: optional string, containing an integer, at least 0
The path cost of reaching the root. A lower number is better. The value is 0 if
this bridge is the root, otherwise it is higher.

rstp_status : rstp_designated_id: optional string
The RSTP designated ID, in the same form as rstp_status:rstp_bridge_id.

rstp_status : rstp_designated_port_id: optional string
The RSTP designated port ID, as a 4-digit hex number.

rstp_status : rstp_bridge_port_id: optional string
The RSTP bridge port ID, as a 4-digit hex number.

Multicast Snooping Configuration:

Multicast snooping (RFC 4541) monitors the Internet Group Management Protocol (IGMP) and
Multicast Listener Discovery traffic between hosts and multicast routers. The switch uses
what IGMP and MLD snooping learns to forward multicast traffic only to interfaces that are
connected to interested receivers. Currently it supports IGMPv1, IGMPv2, IGMPv3, MLDv1 and
MLDv2 protocols.

mcast_snooping_enable: boolean
Enable multicast snooping on the bridge. For now, the default is disabled.

Other Features:

datapath_type: string
Name of datapath provider. The kernel datapath has type system. The userspace
datapath has type netdev. A manager may refer to the datapath_types column of the
Open_vSwitch table for a list of the types accepted by this Open vSwitch instance.

external_ids : bridge-id: optional string
A unique identifier of the bridge.

other_config : hwaddr: optional string
An Ethernet address in the form xx:xx:xx:xx:xx:xx to set the hardware address of
the local port and influence the datapath ID.

other_config : forward-bpdu: optional string, either true or false
Controls forwarding of BPDUs and other network control frames when NORMAL action is
invoked. When this option is false or unset, frames with reserved Ethernet
addresses (see table below) will not be forwarded. When this option is true, such
frames will not be treated specially.

The above general rule has the following exceptions:

• If STP is enabled on the bridge (see the stp_enable column in the Bridge
table), the bridge processes all received STP packets and never passes them
to OpenFlow or forwards them. This is true even if STP is disabled on an
individual port.

• If LLDP is enabled on an interface (see the lldp column in the Interface
table), the interface processes received LLDP packets and never passes them
to OpenFlow or forwards them.

Set this option to true if the Open vSwitch bridge connects different Ethernet
networks and is not configured to participate in STP.

This option affects packets with the following destination MAC addresses:

01:80:c2:00:00:00
IEEE 802.1D Spanning Tree Protocol (STP).

01:80:c2:00:00:01
IEEE Pause frame.

01:80:c2:00:00:0x
Other reserved protocols.

00:e0:2b:00:00:00
Extreme Discovery Protocol (EDP).

00:e0:2b:00:00:04 and 00:e0:2b:00:00:06
Ethernet Automatic Protection Switching (EAPS).

01:00:0c:cc:cc:cc
Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP), Dynamic
Trunking Protocol (DTP), Port Aggregation Protocol (PAgP), and others.

01:00:0c:cc:cc:cd
Cisco Shared Spanning Tree Protocol PVSTP+.

01:00:0c:cd:cd:cd
Cisco STP Uplink Fast.

01:00:0c:00:00:00
Cisco Inter Switch Link.

01:00:0c:cc:cc:cx
Cisco CFM.

other_config : mac-aging-time: optional string, containing an integer, at least 1
The maximum number of seconds to retain a MAC learning entry for which no packets
have been seen. The default is currently 300 seconds (5 minutes). The value, if
specified, is forced into a reasonable range, currently 15 to 3600 seconds.

A short MAC aging time allows a network to more quickly detect that a host is no
longer connected to a switch port. However, it also makes it more likely that
packets will be flooded unnecessarily, when they are addressed to a connected host
that rarely transmits packets. To reduce the incidence of unnecessary flooding, use
a MAC aging time longer than the maximum interval at which a host will ordinarily
transmit packets.

other_config : mac-table-size: optional string, containing an integer, at least 1
The maximum number of MAC addresses to learn. The default is currently 8192. The
value, if specified, is forced into a reasonable range, currently 10 to 1,000,000.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

other_config: map of string-string pairs

external_ids: map of string-string pairs

Port TABLE

A port within a Bridge.

Most commonly, a port has exactly one ``interface,’’ pointed to by its interfaces column.
Such a port logically corresponds to a port on a physical Ethernet switch. A port with
more than one interface is a ``bonded port’’ (see Bonding Configuration).

Some properties that one might think as belonging to a port are actually part of the
port’s Interface members.

Summary:
name immutable string (must be unique within table)
interfaces set of 1 or more Interfaces
VLAN Configuration:
vlan_mode optional string, one of access, dot1q-tunnel, native-tagged,
native-untagged, or trunk
tag optional integer, in range 0 to 4,095
trunks set of up to 4,096 integers, in range 0 to 4,095
cvlans set of up to 4,096 integers, in range 0 to 4,095
other_config : qinq-ethtype
optional string, either 802.1ad or 802.1q
other_config : priority-tags
optional string, one of always, if-nonzero, or never
Bonding Configuration:
bond_mode optional string, one of active-backup, balance-slb, or
balance-tcp
other_config : bond-hash-basis
optional string, containing an integer
other_config : lb-output-action
optional string, either true or false
other_config : bond-primary
optional string
other_config : all-members-active
optional string, either true or false
Link Failure Detection:
other_config : bond-detect-mode
optional string, either carrier or miimon
other_config : bond-miimon-interval
optional string, containing an integer
bond_updelay integer
bond_downdelay integer
LACP Configuration:
lacp optional string, one of active, off, or passive
other_config : lacp-system-id
optional string
other_config : lacp-system-priority
optional string, containing an integer, in range 1 to 65,535
other_config : lacp-time optional string, either fast or slow
other_config : lacp-fallback-ab
optional string, either true or false
Rebalancing Configuration:
other_config : bond-rebalance-interval
optional string, containing an integer, in range 0 to
2,147,483,647
bond_fake_iface boolean
Spanning Tree Protocol:
STP Configuration:
other_config : stp-enable
optional string, either true or false
other_config : stp-port-num
optional string, containing an integer, in range 1 to 255
other_config : stp-port-priority
optional string, containing an integer, in range 0 to 255
other_config : stp-path-cost
optional string, containing an integer, in range 0 to 65,535
STP Status:
status : stp_port_id optional string
status : stp_state optional string, one of blocking, disabled, forwarding,
learning, or listening
status : stp_sec_in_state
optional string, containing an integer, at least 0
status : stp_role optional string, one of alternate, designated, or root
Rapid Spanning Tree Protocol:
RSTP Configuration:
other_config : rstp-enable
optional string, either true or false
other_config : rstp-port-priority
optional string, containing an integer, in range 0 to 240
other_config : rstp-port-num
optional string, containing an integer, in range 1 to 4,095
other_config : rstp-path-cost
optional string, containing an integer
other_config : rstp-port-admin-edge
optional string, either true or false
other_config : rstp-port-auto-edge
optional string, either true or false
other_config : rstp-port-mcheck
optional string, either true or false
RSTP Status:
rstp_status : rstp_port_id
optional string
rstp_status : rstp_port_role
optional string, one of Alternate, Backup, Designated,
Disabled, or Root
rstp_status : rstp_port_state
optional string, one of Disabled, Discarding, Forwarding, or
Learning
rstp_status : rstp_designated_bridge_id
optional string
rstp_status : rstp_designated_port_id
optional string
rstp_status : rstp_designated_path_cost
optional string, containing an integer
RSTP Statistics:
rstp_statistics : rstp_tx_count
optional integer
rstp_statistics : rstp_rx_count
optional integer
rstp_statistics : rstp_error_count
optional integer
rstp_statistics : rstp_uptime
optional integer
Multicast Snooping:
other_config : mcast-snooping-flood
optional string, either true or false
other_config : mcast-snooping-flood-reports
optional string, either true or false
Other Features:
qos optional QoS
mac optional string
fake_bridge boolean
protected boolean
external_ids : fake-bridge-*
optional string
other_config : transient optional string, either true or false
bond_active_slave optional string
Port Statistics:
Statistics: STP transmit and receive counters:
statistics : stp_tx_count
optional integer
statistics : stp_rx_count
optional integer
statistics : stp_error_count
optional integer
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs

Details:
name: immutable string (must be unique within table)
Port name. For a non-bonded port, this should be the same as its interface’s name.
Port names must otherwise be unique among the names of ports, interfaces, and
bridges on a host. Because port and interfaces names are usually the same, the
restrictions on the name column in the Interface table, particularly on length,
also apply to port names. Refer to the documentation for Interface names for
details.

interfaces: set of 1 or more Interfaces
The port’s interfaces. If there is more than one, this is a bonded Port.

VLAN Configuration:

In short, a VLAN (short for ``virtual LAN’’) is a way to partition a single switch into
multiple switches. VLANs can be confusing, so for an introduction, please refer to the
question ``What’s a VLAN?’’ in the Open vSwitch FAQ.

A VLAN is sometimes encoded into a packet using a 802.1Q or 802.1ad VLAN header, but every
packet is part of some VLAN whether or not it is encoded in the packet. (A packet that
appears to have no VLAN is part of VLAN 0, by default.) As a result, it’s useful to think
of a VLAN as a metadata property of a packet, separate from how the VLAN is encoded. For a
given port, this column determines how the encoding of a packet that ingresses or egresses
the port maps to the packet’s VLAN. When a packet enters the switch, its VLAN is
determined based on its setting in this column and its VLAN headers, if any, and then,
conceptually, the VLAN headers are then stripped off. Conversely, when a packet exits the
switch, its VLAN and the settings in this column determine what VLAN headers, if any, are
pushed onto the packet before it egresses the port.

The VLAN configuration in this column affects Open vSwitch only when it is doing ``normal
switching.’’ It does not affect flows set up by an OpenFlow controller, outside of the
OpenFlow ``normal action.’’

Bridge ports support the following types of VLAN configuration:

trunk A trunk port carries packets on one or more specified VLANs specified in the
trunks column (often, on every VLAN). A packet that ingresses on a trunk
port is in the VLAN specified in its 802.1Q header, or VLAN 0 if the packet
has no 802.1Q header. A packet that egresses through a trunk port will have
an 802.1Q header if it has a nonzero VLAN ID.

Any packet that ingresses on a trunk port tagged with a VLAN that the port
does not trunk is dropped.

access An access port carries packets on exactly one VLAN specified in the tag
column. Packets egressing on an access port have no 802.1Q header.

Any packet with an 802.1Q header with a nonzero VLAN ID that ingresses on an
access port is dropped, regardless of whether the VLAN ID in the header is
the access port’s VLAN ID.

native-tagged
A native-tagged port resembles a trunk port, with the exception that a
packet without an 802.1Q header that ingresses on a native-tagged port is in
the ``native VLAN’’ (specified in the tag column).

native-untagged
A native-untagged port resembles a native-tagged port, with the exception
that a packet that egresses on a native-untagged port in the native VLAN
will not have an 802.1Q header.

dot1q-tunnel
A dot1q-tunnel port is somewhat like an access port. Like an access port, it
carries packets on the single VLAN specified in the tag column and this
VLAN, called the service VLAN, does not appear in an 802.1Q header for
packets that ingress or egress on the port. The main difference lies in the
behavior when packets that include a 802.1Q header ingress on the port.
Whereas an access port drops such packets, a dot1q-tunnel port treats these
as double-tagged with the outer service VLAN tag and the inner customer VLAN
taken from the 802.1Q header. Correspondingly, to egress on the port, a
packet outer VLAN (or only VLAN) must be tag, which is removed before
egress, which exposes the inner (customer) VLAN if one is present.

If cvlans is set, only allows packets in the specified customer VLANs.

A packet will only egress through bridge ports that carry the VLAN of the packet, as
described by the rules above.

vlan_mode: optional string, one of access, dot1q-tunnel, native-tagged, native-untagged,
or trunk
The VLAN mode of the port, as described above. When this column is empty, a default
mode is selected as follows:

• If tag contains a value, the port is an access port. The trunks column
should be empty.

• Otherwise, the port is a trunk port. The trunks column value is honored if
it is present.

tag: optional integer, in range 0 to 4,095
For an access port, the port’s implicitly tagged VLAN. For a native-tagged or
native-untagged port, the port’s native VLAN. Must be empty if this is a trunk
port.

trunks: set of up to 4,096 integers, in range 0 to 4,095
For a trunk, native-tagged, or native-untagged port, the 802.1Q VLAN or VLANs that
this port trunks; if it is empty, then the port trunks all VLANs. Must be empty if
this is an access port.

A native-tagged or native-untagged port always trunks its native VLAN, regardless
of whether trunks includes that VLAN.

cvlans: set of up to 4,096 integers, in range 0 to 4,095
For a dot1q-tunnel port, the customer VLANs that this port includes. If this is
empty, the port includes all customer VLANs.

For other kinds of ports, this setting is ignored.

other_config : qinq-ethtype: optional string, either 802.1ad or 802.1q
For a dot1q-tunnel port, this is the TPID for the service tag, that is, for the
802.1Q header that contains the service VLAN ID. Because packets that actually
ingress and egress a dot1q-tunnel port do not include an 802.1Q header for the
service VLAN, this does not affect packets on the dot1q-tunnel port itself. Rather,
it determines the service VLAN for a packet that ingresses on a dot1q-tunnel port
and egresses on a trunk port.

The value 802.1ad specifies TPID 0x88a8, which is also the default if the setting
is omitted. The value 802.1q specifies TPID 0x8100.

For other kinds of ports, this setting is ignored.

other_config : priority-tags: optional string, one of always, if-nonzero, or never
An 802.1Q header contains two important pieces of information: a VLAN ID and a
priority. A frame with a zero VLAN ID, called a ``priority-tagged’’ frame, is
supposed to be treated the same way as a frame without an 802.1Q header at all
(except for the priority).

However, some network elements ignore any frame that has 802.1Q header at all, even
when the VLAN ID is zero. Therefore, by default Open vSwitch does not output
priority-tagged frames, instead omitting the 802.1Q header entirely if the VLAN ID
is zero. Set this key to if-nonzero to enable priority-tagged frames on a port.

For if-nonzero Open vSwitch omits the 802.1Q header on output if both the VLAN ID
and priority would be zero. Set to always to retain the 802.1Q header in such
frames as well.

All frames output to native-tagged ports have a nonzero VLAN ID, so this setting is
not meaningful on native-tagged ports.

Bonding Configuration:

A port that has more than one interface is a ``bonded port.’’ Bonding allows for load
balancing and fail-over.

The following types of bonding will work with any kind of upstream switch. On the upstream
switch, do not configure the interfaces as a bond:

balance-slb
Balances flows among members based on source MAC address and output VLAN,
with periodic rebalancing as traffic patterns change.

active-backup
Assigns all flows to one member, failing over to a backup member when the
active member is disabled. This is the only bonding mode in which interfaces
may be plugged into different upstream switches.

The following modes require the upstream switch to support 802.3ad with successful LACP
negotiation. If LACP negotiation fails and other-config:lacp-fallback-ab is true, then
active-backup mode is used:

balance-tcp
Balances flows among members based on L3 and L4 protocol information such as
IP addresses and TCP/UDP ports.

These columns apply only to bonded ports. Their values are otherwise ignored.

bond_mode: optional string, one of active-backup, balance-slb, or balance-tcp
The type of bonding used for a bonded port. Defaults to active-backup if unset.

other_config : bond-hash-basis: optional string, containing an integer
An integer hashed along with flows when choosing output members in load balanced
bonds. When changed, all flows will be assigned different hash values possibly
causing member selection decisions to change. Does not affect bonding modes which
do not employ load balancing such as active-backup.

other_config : lb-output-action: optional string, either true or false
Enable/disable usage of optimized lb_output action for balancing flows among output
members in load balanced bonds in balance-tcp. When enabled, it uses optimized path
for balance-tcp mode by using rss hash and avoids recirculation. This knob does not
affect other balancing modes.

other_config : bond-primary: optional string
If a slave interface with this name exists in the bond and is up, it will be made
active. Relevant only when other_config:bond_mode is active-backup or if
balance-tcp falls back to active-backup (e.g., LACP negotiation fails and
other_config:lacp-fallback-ab is true).

other_config : all-members-active: optional string, either true or false
Enable/Disable delivery of broadcast/multicast packets on secondary interface of a
balance-slb bond. Relevant only when lacp is off.

This parameter is identical to all_slaves_active for Linux kernel bonds. Disabled
by default as it is not a desirable configuration for most users.

Link Failure Detection:

An important part of link bonding is detecting that links are down so that they may be
disabled. These settings determine how Open vSwitch detects link failure.

other_config : bond-detect-mode: optional string, either carrier or miimon
The means used to detect link failures. Defaults to carrier which uses each
interface’s carrier to detect failures. When set to miimon, will check for failures
by polling each interface’s MII.

other_config : bond-miimon-interval: optional string, containing an integer
The interval, in milliseconds, between successive attempts to poll each interface’s
MII. Relevant only when other_config:bond-detect-mode is miimon.

bond_updelay: integer
The number of milliseconds for which the link must stay up on an interface before
the interface is considered to be up. Specify 0 to enable the interface
immediately.

This setting is honored only when at least one bonded interface is already enabled.
When no interfaces are enabled, then the first bond interface to come up is enabled
immediately.

bond_downdelay: integer
The number of milliseconds for which the link must stay down on an interface before
the interface is considered to be down. Specify 0 to disable the interface
immediately.

LACP Configuration:

LACP, the Link Aggregation Control Protocol, is an IEEE standard that allows switches to
automatically detect that they are connected by multiple links and aggregate across those
links. These settings control LACP behavior.

lacp: optional string, one of active, off, or passive
Configures LACP on this port. LACP allows directly connected switches to negotiate
which links may be bonded. LACP may be enabled on non-bonded ports for the benefit
of any switches they may be connected to. active ports are allowed to initiate LACP
negotiations. passive ports are allowed to participate in LACP negotiations
initiated by a remote switch, but not allowed to initiate such negotiations
themselves. If LACP is enabled on a port whose partner switch does not support
LACP, the bond will be disabled, unless other-config:lacp-fallback-ab is set to
true. Defaults to off if unset.

other_config : lacp-system-id: optional string
The LACP system ID of this Port. The system ID of a LACP bond is used to identify
itself to its partners. Must be a nonzero MAC address. Defaults to the bridge
Ethernet address if unset.

other_config : lacp-system-priority: optional string, containing an integer, in range 1 to
65,535
The LACP system priority of this Port. In LACP negotiations, link status decisions
are made by the system with the numerically lower priority.

other_config : lacp-time: optional string, either fast or slow
The LACP timing which should be used on this Port. By default slow is used. When
configured to be fast LACP heartbeats are requested at a rate of once per second
causing connectivity problems to be detected more quickly. In slow mode, heartbeats
are requested at a rate of once every 30 seconds.

other_config : lacp-fallback-ab: optional string, either true or false
Determines the behavior of openvswitch bond in LACP mode. If the partner switch
does not support LACP, setting this option to true allows openvswitch to fallback
to active-backup. If the option is set to false, the bond will be disabled. In both
the cases, once the partner switch is configured to LACP mode, the bond will use
LACP.

Rebalancing Configuration:

These settings control behavior when a bond is in balance-slb or balance-tcp mode.

other_config : bond-rebalance-interval: optional string, containing an integer, in range 0
to 2,147,483,647
For a load balanced bonded port, the number of milliseconds between successive
attempts to rebalance the bond, that is, to move flows from one interface on the
bond to another in an attempt to keep usage of each interface roughly equal. If
zero, load balancing is disabled on the bond (link failure still cause flows to
move). If less than 1000ms, the rebalance interval will be 1000ms.

bond_fake_iface: boolean
For a bonded port, whether to create a fake internal interface with the name of the
port. Use only for compatibility with legacy software that requires this.

Spanning Tree Protocol:

The configuration here is only meaningful, and the status is only populated, when
802.1D-1998 Spanning Tree Protocol is enabled on the port’s Bridge with its stp_enable
column.

STP Configuration:

other_config : stp-enable: optional string, either true or false
When STP is enabled on a bridge, it is enabled by default on all of the bridge’s
ports except bond, internal, and mirror ports (which do not work with STP). If this
column’s value is false, STP is disabled on the port.

other_config : stp-port-num: optional string, containing an integer, in range 1 to 255
The port number used for the lower 8 bits of the port-id. By default, the numbers
will be assigned automatically. If any port’s number is manually configured on a
bridge, then they must all be.

other_config : stp-port-priority: optional string, containing an integer, in range 0 to
255
The port’s relative priority value for determining the root port (the upper 8 bits
of the port-id). A port with a lower port-id will be chosen as the root port. By
default, the priority is 0x80.

other_config : stp-path-cost: optional string, containing an integer, in range 0 to 65,535
Spanning tree path cost for the port. A lower number indicates a faster link. By
default, the cost is based on the maximum speed of the link.

STP Status:

status : stp_port_id: optional string
The port ID used in spanning tree advertisements for this port, as 4 hex digits.
Configuring the port ID is described in the stp-port-num and stp-port-priority keys
of the other_config section earlier.

status : stp_state: optional string, one of blocking, disabled, forwarding, learning, or
listening
STP state of the port.

status : stp_sec_in_state: optional string, containing an integer, at least 0
The amount of time this port has been in the current STP state, in seconds.

status : stp_role: optional string, one of alternate, designated, or root
STP role of the port.

Rapid Spanning Tree Protocol:

The configuration here is only meaningful, and the status and statistics are only
populated, when 802.1D-1998 Spanning Tree Protocol is enabled on the port’s Bridge with
its stp_enable column.

RSTP Configuration:

other_config : rstp-enable: optional string, either true or false
When RSTP is enabled on a bridge, it is enabled by default on all of the bridge’s
ports except bond, internal, and mirror ports (which do not work with RSTP). If
this column’s value is false, RSTP is disabled on the port.

other_config : rstp-port-priority: optional string, containing an integer, in range 0 to
240
The port’s relative priority value for determining the root port, in multiples of
16. By default, the port priority is 0x80 (128). Any value in the lower 4 bits is
rounded off. The significant upper 4 bits become the upper 4 bits of the port-id. A
port with the lowest port-id is elected as the root.

other_config : rstp-port-num: optional string, containing an integer, in range 1 to 4,095
The local RSTP port number, used as the lower 12 bits of the port-id. By default
the port numbers are assigned automatically, and typically may not correspond to
the OpenFlow port numbers. A port with the lowest port-id is elected as the root.

other_config : rstp-path-cost: optional string, containing an integer
The port path cost. The Port’s contribution, when it is the Root Port, to the Root
Path Cost for the Bridge. By default the cost is automatically calculated from the
port’s speed.

other_config : rstp-port-admin-edge: optional string, either true or false
The admin edge port parameter for the Port. Default is false.

other_config : rstp-port-auto-edge: optional string, either true or false
The auto edge port parameter for the Port. Default is true.

other_config : rstp-port-mcheck: optional string, either true or false
The mcheck port parameter for the Port. Default is false. May be set to force the
Port Protocol Migration state machine to transmit RST BPDUs for a MigrateTime
period, to test whether all STP Bridges on the attached LAN have been removed and
the Port can continue to transmit RSTP BPDUs. Setting mcheck has no effect if the
Bridge is operating in STP Compatibility mode.

Changing the value from true to false has no effect, but needs to be done if this
behavior is to be triggered again by subsequently changing the value from false to
true.

RSTP Status:

rstp_status : rstp_port_id: optional string
The port ID used in spanning tree advertisements for this port, as 4 hex digits.
Configuring the port ID is described in the rstp-port-num and rstp-port-priority
keys of the other_config section earlier.

rstp_status : rstp_port_role: optional string, one of Alternate, Backup, Designated,
Disabled, or Root
RSTP role of the port.

rstp_status : rstp_port_state: optional string, one of Disabled, Discarding, Forwarding,
or Learning
RSTP state of the port.

rstp_status : rstp_designated_bridge_id: optional string
The port’s RSTP designated bridge ID, in the same form as
rstp_status:rstp_bridge_id in the Bridge table.

rstp_status : rstp_designated_port_id: optional string
The port’s RSTP designated port ID, as 4 hex digits.

rstp_status : rstp_designated_path_cost: optional string, containing an integer
The port’s RSTP designated path cost. Lower is better.

RSTP Statistics:

rstp_statistics : rstp_tx_count: optional integer
Number of RSTP BPDUs transmitted through this port.

rstp_statistics : rstp_rx_count: optional integer
Number of valid RSTP BPDUs received by this port.

rstp_statistics : rstp_error_count: optional integer
Number of invalid RSTP BPDUs received by this port.

rstp_statistics : rstp_uptime: optional integer
The duration covered by the other RSTP statistics, in seconds.

Multicast Snooping:

other_config : mcast-snooping-flood: optional string, either true or false
If set to true, multicast packets (except Reports) are unconditionally forwarded to
the specific port.

other_config : mcast-snooping-flood-reports: optional string, either true or false
If set to true, multicast Reports are unconditionally forwarded to the specific
port.

Other Features:

qos: optional QoS
Quality of Service configuration for this port.

mac: optional string
The MAC address to use for this port for the purpose of choosing the bridge’s MAC
address. This column does not necessarily reflect the port’s actual MAC address,
nor will setting it change the port’s actual MAC address.

fake_bridge: boolean
Does this port represent a sub-bridge for its tagged VLAN within the Bridge? See
ovs-vsctl(8) for more information.

protected: boolean
The protected ports feature allows certain ports to be designated as protected.
Traffic between protected ports is blocked. Protected ports can send traffic to
unprotected ports. Unprotected ports can send traffic to any port. Default is
false.

external_ids : fake-bridge-*: optional string
External IDs for a fake bridge (see the fake_bridge column) are defined by
prefixing a Bridge external_ids key with fake-bridge-, e.g. fake-bridge-bridge-id.

other_config : transient: optional string, either true or false
If set to true, the port will be removed when ovs-ctl start
--delete-transient-ports is used.

bond_active_slave: optional string
For a bonded port, record the MAC address of the current active member.

Port Statistics:

Key-value pairs that report port statistics. The update period is controlled by
other_config:stats-update-interval in the Open_vSwitch table.

Statistics: STP transmit and receive counters:

statistics : stp_tx_count: optional integer
Number of STP BPDUs sent on this port by the spanning tree library.

statistics : stp_rx_count: optional integer
Number of STP BPDUs received on this port and accepted by the spanning tree
library.

statistics : stp_error_count: optional integer
Number of bad STP BPDUs received on this port. Bad BPDUs include runt packets and
those with an unexpected protocol ID.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

other_config: map of string-string pairs

external_ids: map of string-string pairs

Interface TABLE

An interface within a Port.

Summary:
Core Features:
name immutable string (must be unique within table)
ifindex optional integer, in range 0 to 4,294,967,295
mac_in_use optional string
mac optional string
error optional string
OpenFlow Port Number:
ofport optional integer
ofport_request optional integer, in range 1 to 65,279
System-Specific Details:
type string
Tunnel Options:
options : remote_ip optional string
options : local_ip optional string
options : in_key optional string
options : out_key optional string
options : dst_port optional string
options : key optional string
options : tos optional string
options : ttl optional string
options : df_default optional string, either true or false
options : egress_pkt_mark optional string
Tunnel Options: lisp only:
options : packet_type optional string, either legacy_l3 or ptap
Tunnel Options: vxlan only:
options : exts optional string
options : packet_type optional string, one of legacy_l2, legacy_l3, or ptap
Tunnel Options: gre only:
options : packet_type optional string, one of legacy_l2, legacy_l3, or ptap
options : seq optional string, either true or false
Tunnel Options: gre, ip6gre, geneve, bareudp and vxlan:
options : csum optional string, either true or false
Tunnel Options: IPsec:
options : psk optional string
options : remote_cert optional string
options : remote_name optional string
Tunnel Options: erspan only:
options : erspan_idx optional string
options : erspan_ver optional string
options : erspan_dir optional string
options : erspan_hwid optional string
Tunnel Options: Bareudp only:
options : payload_type optional string
Tunnel Options: srv6 only:
options : srv6_segs optional string
options : srv6_flowlabel optional string, one of compute, copy, or zero
Patch Options:
options : peer optional string
PMD (Poll Mode Driver) Options:
options : n_rxq optional string, containing an integer, at least 1
options : dpdk-devargs optional string
other_config : pmd-rxq-affinity
optional string
options : xdp-mode optional string, one of best-effort, generic,
native-with-zerocopy, or native
options : use-need-wakeup optional string, either true or false
options : vhost-server-path
optional string
options : tx-retries-max optional string, containing an integer, in range 0 to 32
options : n_rxq_desc optional string, containing an integer, in range 1 to 4,096
options : n_txq_desc optional string, containing an integer, in range 1 to 4,096
options : dpdk-vf-mac optional string
options : rx-steering optional string, either rss+lacp or rss
other_config : tx-steering optional string, either hash or thread
EMC (Exact Match Cache) Configuration:
other_config : emc-enable optional string, either true or false
MTU:
mtu optional integer
mtu_request optional integer, at least 1
Interface Status:
admin_state optional string, either down or up
link_state optional string, either down or up
link_resets optional integer
link_speed optional integer
duplex optional string, either full or half
lacp_current optional boolean
status map of string-string pairs
status : driver_name optional string
status : driver_version optional string
status : firmware_version optional string
status : source_ip optional string
status : tunnel_egress_iface
optional string
status : tunnel_egress_iface_carrier
optional string, either down or up
dpdk:
status : port_no optional string
status : numa_id optional string
status : min_rx_bufsize optional string
status : max_rx_pktlen optional string
status : max_rx_queues optional string
status : max_tx_queues optional string
status : max_mac_addrs optional string
status : max_hash_mac_addrs
optional string
status : max_vfs optional string
status : max_vmdq_pools optional string
status : if_type optional string
status : if_descr optional string
status : bus_info optional string
status : dpdk-vf-mac optional string
status : rx_steering optional string
status : rx_steering_queue
optional string
status : rss_queues optional string
dpdkvhostuser:
status : mode optional string
status : features optional string
status : num_of_vrings optional string
status : numa optional string
status : socket optional string
status : status optional string
status : vring_n_size optional string
status : userspace-tso optional string
Statistics:
Statistics: Successful transmit and receive counters:
statistics : rx_packets optional integer
statistics : rx_bytes optional integer
statistics : tx_packets optional integer
statistics : tx_bytes optional integer
Statistics: Receive errors:
statistics : rx_dropped optional integer
statistics : rx_frame_err
optional integer
statistics : rx_over_err optional integer
statistics : rx_crc_err optional integer
statistics : rx_errors optional integer
Statistics: Transmit errors:
statistics : tx_dropped optional integer
statistics : collisions optional integer
statistics : tx_errors optional integer
Ingress Policing:
ingress_policing_rate integer, at least 0
ingress_policing_kpkts_rate
integer, at least 0
ingress_policing_burst integer, at least 0
ingress_policing_kpkts_burst
integer, at least 0
Bidirectional Forwarding Detection (BFD):
BFD Configuration:
bfd : enable optional string, either true or false
bfd : min_rx optional string, containing an integer, at least 1
bfd : min_tx optional string, containing an integer, at least 1
bfd : decay_min_rx optional string, containing an integer
bfd : forwarding_if_rx optional string, either true or false
bfd : cpath_down optional string, either true or false
bfd : check_tnl_key optional string, either true or false
bfd : bfd_local_src_mac optional string
bfd : bfd_local_dst_mac optional string
bfd : bfd_remote_dst_mac optional string
bfd : bfd_src_ip optional string
bfd : bfd_dst_ip optional string
bfd : oam optional string
bfd : mult optional string, containing an integer, in range 1 to 255
BFD Status:
bfd_status : state optional string, one of admin_down, down, init, or up
bfd_status : forwarding optional string, either true or false
bfd_status : diagnostic optional string
bfd_status : remote_state
optional string, one of admin_down, down, init, or up
bfd_status : remote_diagnostic
optional string
bfd_status : flap_count optional string, containing an integer, at least 0
Connectivity Fault Management:
cfm_mpid optional integer
cfm_flap_count optional integer
cfm_fault optional boolean
cfm_fault_status : recv none
cfm_fault_status : rdi none
cfm_fault_status : maid none
cfm_fault_status : loopback
none
cfm_fault_status : overflow
none
cfm_fault_status : override
none
cfm_fault_status : interval
none
cfm_remote_opstate optional string, either down or up
cfm_health optional integer, in range 0 to 100
cfm_remote_mpids set of integers
other_config : cfm_interval
optional string, containing an integer
other_config : cfm_extended
optional string, either true or false
other_config : cfm_demand optional string, either true or false
other_config : cfm_opstate optional string, either down or up
other_config : cfm_ccm_vlan
optional string, containing an integer, in range 1 to 4,095
other_config : cfm_ccm_pcp optional string, containing an integer, in range 1 to 7
Bonding Configuration:
other_config : lacp-port-id
optional string, containing an integer, in range 1 to 65,535
other_config : lacp-port-priority
optional string, containing an integer, in range 1 to 65,535
other_config : lacp-aggregation-key
optional string, containing an integer, in range 1 to 65,535
Virtual Machine Identifiers:
external_ids : attached-mac
optional string
external_ids : iface-id optional string
external_ids : iface-status
optional string, either active or inactive
external_ids : vm-id optional string
Auto Attach Configuration:
lldp : enable optional string, either true or false
Flow control Configuration:
options : rx-flow-ctrl optional string, either true or false
options : tx-flow-ctrl optional string, either true or false
options : flow-ctrl-autoneg
optional string, either true or false
Link State Change detection mode:
options : dpdk-lsc-interrupt
optional string, either true or false
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs

Details:
Core Features:

name: immutable string (must be unique within table)
Interface name. Should be alphanumeric. For non-bonded port, this should be the
same as the port name. It must otherwise be unique among the names of ports,
interfaces, and bridges on a host.

The maximum length of an interface name depends on the underlying datapath:

• The names of interfaces implemented as Linux and BSD network devices,
including interfaces with type internal, tap, or system plus the different
types of tunnel ports, are limited to 15 bytes. Windows limits these names
to 255 bytes.

• The names of patch ports are not used in the underlying datapath, so
operating system restrictions do not apply. Thus, they may have arbitrary
length.

Regardless of other restrictions, OpenFlow only supports 15-byte names, which means
that ovs-ofctl and OpenFlow controllers will show names truncated to 15 bytes.

ifindex: optional integer, in range 0 to 4,294,967,295
A positive interface index as defined for SNMP MIB-II in RFCs 1213 and 2863, if the
interface has one, otherwise 0. The ifindex is useful for seamless integration with
protocols such as SNMP and sFlow.

mac_in_use: optional string
The MAC address in use by this interface.

mac: optional string
Ethernet address to set for this interface. If unset then the default MAC address
is used:

• For the local interface, the default is the lowest-numbered MAC address
among the other bridge ports, either the value of the mac in its Port
record, if set, or its actual MAC (for bonded ports, the MAC of its member
whose name is first in alphabetical order). Internal ports and bridge ports
that are used as port mirroring destinations (see the Mirror table) are
ignored.

• For other internal interfaces, the default MAC is randomly generated.

• External interfaces typically have a MAC address associated with their
hardware.

Some interfaces may not have a software-controllable MAC address. This option only
affects internal ports. For other type ports, you can change the MAC address
outside Open vSwitch, using ip command.

error: optional string
If the configuration of the port failed, as indicated by -1 in ofport, Open vSwitch
sets this column to an error description in human readable form. Otherwise, Open
vSwitch clears this column.

OpenFlow Port Number:

When a client adds a new interface, Open vSwitch chooses an OpenFlow port number for the
new port. If the client that adds the port fills in ofport_request, then Open vSwitch
tries to use its value as the OpenFlow port number. Otherwise, or if the requested port
number is already in use or cannot be used for another reason, Open vSwitch automatically
assigns a free port number. Regardless of how the port number was obtained, Open vSwitch
then reports in ofport the port number actually assigned.

Open vSwitch limits the port numbers that it automatically assigns to the range 1 through
32,767, inclusive. Controllers therefore have free use of ports 32,768 and up.

ofport: optional integer
OpenFlow port number for this interface. Open vSwitch sets this column’s value, so
other clients should treat it as read-only.

The OpenFlow ``local’’ port (OFPP_LOCAL) is 65,534. The other valid port numbers
are in the range 1 to 65,279, inclusive. Value -1 indicates an error adding the
interface.

ofport_request: optional integer, in range 1 to 65,279
Requested OpenFlow port number for this interface.

A client should ideally set this column’s value in the same database transaction
that it uses to create the interface. Open vSwitch version 2.1 and later will honor
a later request for a specific port number, althuogh it might confuse some
controllers: OpenFlow does not have a way to announce a port number change, so Open
vSwitch represents it over OpenFlow as a port deletion followed immediately by a
port addition.

If ofport_request is set or changed to some other port’s automatically assigned
port number, Open vSwitch chooses a new port number for the latter port.

System-Specific Details:

type: string
The interface type. The types supported by a particular instance of Open vSwitch
are listed in the iface_types column in the Open_vSwitch table. The following types
are defined:

system An ordinary network device, e.g. eth0 on Linux. Sometimes referred to as
``external interfaces’’ since they are generally connected to hardware
external to that on which the Open vSwitch is running. The empty string is a
synonym for system.

internal
A simulated network device that sends and receives traffic. An internal
interface whose name is the same as its bridge’s name is called the ``local
interface.’’ It does not make sense to bond an internal interface, so the
terms ``port’’ and ``interface’’ are often used imprecisely for internal
interfaces.

tap A TUN/TAP device managed by Open vSwitch.

Open vSwitch checks the interface state before send packets to the device.
When it is down, the packets are dropped and the tx_dropped statistic is
updated accordingly. Older versions of Open vSwitch did not check the
interface state and then the tx_packets was incremented along with
tx_dropped.

geneve An Ethernet over Geneve (http://tools.ietf.org/html/draft-ietf-nvo3-geneve)
IPv4/IPv6 tunnel. A description of how to match and set Geneve options can
be found in the ovs-ofctl manual page.

gre Generic Routing Encapsulation (GRE) over IPv4 tunnel, configurable to
encapsulate layer 2 or layer 3 traffic.

ip6gre Generic Routing Encapsulation (GRE) over IPv6 tunnel, encapsulate layer 2
traffic.

vxlan An Ethernet tunnel over the UDP-based VXLAN protocol described in RFC 7348.

Open vSwitch uses IANA-assigned UDP destination port 4789. The source port
used for VXLAN traffic varies on a per-flow basis and is in the ephemeral
port range.

lisp A layer 3 tunnel over the experimental, UDP-based Locator/ID Separation
Protocol (RFC 6830).

Only IPv4 and IPv6 packets are supported by the protocol, and they are sent
and received without an Ethernet header. Traffic to/from LISP ports is
expected to be configured explicitly, and the ports are not intended to
participate in learning based switching. As such, they are always excluded
from packet flooding.

stt The Stateless TCP Tunnel (STT) is particularly useful when tunnel endpoints
are in end-systems, as it utilizes the capabilities of standard network
interface cards to improve performance. STT utilizes a TCP-like header
inside the IP header. It is stateless, i.e., there is no TCP connection
state of any kind associated with the tunnel. The TCP-like header is used to
leverage the capabilities of existing network interface cards, but should
not be interpreted as implying any sort of connection state between
endpoints. Since the STT protocol does not engage in the usual TCP 3-way
handshake, so it will have difficulty traversing stateful firewalls. The
protocol is documented at https://tools.ietf.org/html/draft-davie-stt All
traffic uses a default destination port of 7471.

patch A pair of virtual devices that act as a patch cable.

gtpu GPRS Tunneling Protocol (GTP) is a group of IP-based communications
protocols used to carry general packet radio service (GPRS) within GSM, UMTS
and LTE networks. GTP-U is used for carrying user data within the GPRS core
network and between the radio access network and the core network. The user
data transported can be packets in any of IPv4, IPv6, or PPP formats.

The protocol is documented at http://www.3gpp.org/DynaReport/29281.htm

Open vSwitch uses UDP destination port 2152. The source port used for GTP
traffic varies on a per-flow basis and is in the ephemeral port range.

Bareudp
The Bareudp tunnel provides a generic L3 encapsulation support for
tunnelling different L3 protocols like MPLS, IP, NSH etc. inside a UDP
tunnel.

srv6 Segment Routing IPv6 (SRv6) tunnel encapsulates L3 traffic as "IPv6 in IPv6"
or "IPv4 in IPv6" with Segment Routing Header (SRH) defined in RFC 8754. The
segment list in SRH can be set using a SRv6 specific option.

Tunnel Options:

These options apply to interfaces with type of geneve, bareudp, gre, ip6gre, vxlan, lisp,
stt and srv6.

Each tunnel must be uniquely identified by the combination of type, options:remote_ip,
options:local_ip, and options:in_key. If two ports are defined that are the same except
one has an optional identifier and the other does not, the more specific one is matched
first. options:in_key is considered more specific than options:local_ip if a port defines
one and another port defines the other. options:in_key is not applicable for bareudp and
srv6 tunnels. Hence it is not considered while identifying bareudp or srv6 tunnels.

options : remote_ip: optional string
Required. The remote tunnel endpoint, one of:

• An IPv4 or IPv6 address (not a DNS name), e.g. 192.168.0.123. Only unicast
endpoints are supported.

• The word flow. The tunnel accepts packets from any remote tunnel endpoint.
To process only packets from a specific remote tunnel endpoint, the flow
entries may match on the tun_src or tun_ipv6_srcfield. When sending packets
to a remote_ip=flow tunnel, the flow actions must explicitly set the tun_dst
or tun_ipv6_dst field to the IP address of the desired remote tunnel
endpoint, e.g. with a set_field action.

The remote tunnel endpoint for any packet received from a tunnel is available in
the tun_src field for matching in the flow table.

options : local_ip: optional string
Optional. The tunnel destination IP that received packets must match. Default is to
match all addresses. If specified, may be one of:

• An IPv4/IPv6 address (not a DNS name), e.g. 192.168.12.3.

• The word flow. The tunnel accepts packets sent to any of the local IP
addresses of the system running OVS. To process only packets sent to a
specific IP address, the flow entries may match on the tun_dst or
tun_ipv6_dst field. When sending packets to a local_ip=flow tunnel, the flow
actions may explicitly set the tun_src or tun_ipv6_src field to the desired
IP address, e.g. with a set_field action. However, while routing the
tunneled packet out, the local system may override the specified address
with the local IP address configured for the outgoing system interface.

This option is valid only for tunnels also configured with the
remote_ip=flow option.

The tunnel destination IP address for any packet received from a tunnel is
available in the tun_dst or tun_ipv6_dst field for matching in the flow table.

options : in_key: optional string
Optional, not applicable for bareudp and srv6. The key that received packets must
contain, one of:

• 0. The tunnel receives packets with no key or with a key of 0. This is
equivalent to specifying no options:in_key at all.

• A positive 24-bit (for Geneve, VXLAN, and LISP), 32-bit (for GRE) or 64-bit
(for STT) number. The tunnel receives only packets with the specified key.

• The word flow. The tunnel accepts packets with any key. The key will be
placed in the tun_id field for matching in the flow table. The ovs-fields(7)
manual page contains additional information about matching fields in
OpenFlow flows.

options : out_key: optional string
Optional, not applicable for bareudp and srv6. The key to be set on outgoing
packets, one of:

• 0. Packets sent through the tunnel will have no key. This is equivalent to
specifying no options:out_key at all.

• A positive 24-bit (for Geneve, VXLAN and LISP), 32-bit (for GRE) or 64-bit
(for STT) number. Packets sent through the tunnel will have the specified
key.

• The word flow. Packets sent through the tunnel will have the key set using
the set_tunnel Nicira OpenFlow vendor extension (0 is used in the absence of
an action). The ovs-fields(7) manual page contains additional information
about the Nicira OpenFlow vendor extensions.

options : dst_port: optional string
Optional. The tunnel transport layer destination port, for UDP and TCP based tunnel
protocols (Geneve, VXLAN, LISP, and STT).

options : key: optional string
Optional. Shorthand to set in_key and out_key at the same time.

options : tos: optional string
Optional. The value of the ToS bits to be set on the encapsulating packet. ToS is
interpreted as DSCP and ECN bits, ECN part must be zero. It may also be the word
inherit, in which case the ToS will be copied from the inner packet if it is IPv4
or IPv6 (otherwise it will be 0). The ECN fields are always inherited. Default is
0.

options : ttl: optional string
Optional. The TTL to be set on the encapsulating packet. It may also be the word
inherit, in which case the TTL will be copied from the inner packet if it is IPv4
or IPv6 (otherwise it will be the system default, typically 64). Default is the
system default TTL.

options : df_default: optional string, either true or false
Optional. If enabled, the Don’t Fragment bit will be set on tunnel outer headers to
allow path MTU discovery. Default is enabled; set to false to disable.

options : egress_pkt_mark: optional string
Optional. The pkt_mark to be set on the encapsulating packet. This option sets
packet mark for the tunnel endpoint for all tunnel packets including tunnel
monitoring.

Tunnel Options: lisp only:

options : packet_type: optional string, either legacy_l3 or ptap
A LISP tunnel sends and receives only IPv4 and IPv6 packets. This option controls
what how the tunnel represents the packets that it sends and receives:

• By default, or if this option is legacy_l3, the tunnel represents packets as
Ethernet frames for compatibility with legacy OpenFlow controllers that
expect this behavior.

• If this option is ptap, the tunnel represents packets using the packet_type
mechanism introduced in OpenFlow 1.5.

Tunnel Options: vxlan only:

options : exts: optional string
Optional. Comma separated list of optional VXLAN extensions to enable. The
following extensions are supported:

• gbp: VXLAN-GBP allows to transport the group policy context of a packet
across the VXLAN tunnel to other network peers. See the description of
tun_gbp_id and tun_gbp_flags in ovs-fields(7) for additional information.
(https://tools.ietf.org/html/draft-smith-vxlan-group-policy)

• gpe: Support for Generic Protocol Encapsulation in accordance with IETF
draft https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe. Without this
option, a VXLAN packet always encapsulates an Ethernet frame. With this
option, an VXLAN packet may also encapsulate an IPv4, IPv6, NSH, or MPLS
packet.

options : packet_type: optional string, one of legacy_l2, legacy_l3, or ptap
This option controls what types of packets the tunnel sends and receives and how it
represents them:

• By default, or if this option is legacy_l2, the tunnel sends and receives
only Ethernet frames.

• If this option is legacy_l3, the tunnel sends and receives only non-Ethernet
(L3) packet, but the packets are represented as Ethernet frames for
compatibility with legacy OpenFlow controllers that expect this behavior.
This requires enabling gpe in options:exts.

• If this option is ptap, Open vSwitch represents packets in the tunnel using
the packet_type mechanism introduced in OpenFlow 1.5. This mechanism
supports any kind of packet, but actually sending and receiving non-Ethernet
packets requires additionally enabling gpe in options:exts.

Tunnel Options: gre only:

gre interfaces support these options.

options : packet_type: optional string, one of legacy_l2, legacy_l3, or ptap
This option controls what types of packets the tunnel sends and receives and how it
represents them:

• By default, or if this option is legacy_l2, the tunnel sends and receives
only Ethernet frames.

• The legacy_l3 option is only available via the user space datapath. The OVS
kernel datapath does not support devices of type ARPHRD_IPGRE which is the
requirement for legacy_l3 type packets.

• If this option is ptap, the tunnel sends and receives any kind of packet.
Open vSwitch represents packets in the tunnel using the packet_type
mechanism introduced in OpenFlow 1.5.

options : seq: optional string, either true or false
Optional. A 4-byte sequence number field for GRE tunnel only. Default is disabled,
set to true to enable. Sequence number is incremented by one on each outgoing
packet.

Tunnel Options: gre, ip6gre, geneve, bareudp and vxlan:

gre, ip6gre, geneve, bareudp and vxlan interfaces support these options.

options : csum: optional string, either true or false
Optional. Compute encapsulation header (either GRE or UDP) checksums on outgoing
packets. Default is disabled, set to true to enable. Checksums present on incoming
packets will be validated regardless of this setting.

When using the upstream Linux kernel module, computation of checksums for geneve
and vxlan requires Linux kernel version 4.0 or higher. gre and ip6gre support
checksums for all versions of Open vSwitch that support GRE. The out of tree kernel
module distributed as part of OVS can compute all tunnel checksums on any kernel
version that it is compatible with.

Tunnel Options: IPsec:

Setting any of these options enables IPsec support for a given tunnel. gre, geneve, vxlan
and stt interfaces support these options. See the IPsec section in the Open_vSwitch table
for a description of each mode.

options : psk: optional string
In PSK mode only, the preshared secret to negotiate tunnel. This value must match
on both tunnel ends.

options : remote_cert: optional string
In self-signed certificate mode only, name of a PEM file containing a certificate
of the remote switch. The certificate must be x.509 version 3 and with the string
in common name (CN) also set in the subject alternative name (SAN).

options : remote_name: optional string
In CA-signed certificate mode only, common name (CN) of the remote certificate.

Tunnel Options: erspan only:

Only erspan interfaces support these options.

options : erspan_idx: optional string
20 bit index/port number associated with the ERSPAN traffic’s source port and
direction (ingress/egress). This field is platform dependent.

options : erspan_ver: optional string
ERSPAN version: 1 for version 1 (type II) or 2 for version 2 (type III).

options : erspan_dir: optional string
Specifies the ERSPAN v2 mirrored traffic’s direction. 1 for egress traffic, and 0
for ingress traffic.

options : erspan_hwid: optional string
ERSPAN hardware ID is a 6-bit unique identifier of an ERSPAN v2 engine within a
system.

Tunnel Options: Bareudp only:

options : payload_type: optional string
Specifies the ethertype of the l3 protocol the bareudp device is tunnelling. For
the tunnels which supports multiple ethertypes of a l3 protocol (IP, MPLS) this
field specifies the protocol name as a string.

Tunnel Options: srv6 only:

options : srv6_segs: optional string
Specifies the segment list in Segment Routing Header (SRH). It consists of a comma-
separated list of segments represented in IPv6 format, e.g.
"fc00:100::1,fc00:200::1,fc00:300::1". Note that the first segment must be the same
as options:remote_ip.

options : srv6_flowlabel: optional string, one of compute, copy, or zero
Optional. This option controls how flowlabel in outer IPv6 header is configured. It
gives the benefit of IPv6 flow label based load balancing, which is supported by
some popular vendor appliances. Like net.ipv6.seg6_flowlabel sysconfig, it is one
of the three values below:

• By default, or if this option is copy, copy the flowlabel of inner IPv6
header to the flowlabel of outer IPv6 header. If inner header is not IPv6,
it is set to 0.

• If this option is zero, simply set flowlabel to 0.

• If this option is compute, set flowlabel to a hash over the L3/L4 fields of
the inner packet.

Patch Options:

These options apply only to patch ports, that is, interfaces whose type column is patch.
Patch ports are mainly a way to connect otherwise independent bridges to one another,
similar to how one might plug an Ethernet cable (a ``patch cable’’) into two physical
switches to connect those switches. The effect of plugging a patch port into two switches
is conceptually similar to that of plugging the two ends of a Linux veth device into those
switches, but the implementation of patch ports makes them much more efficient.

Patch ports may connect two different bridges (the usual case) or the same bridge. In the
latter case, take special care to avoid loops, e.g. by programming appropriate flows with
OpenFlow. Patch ports do not work if its ends are attached to bridges on different
datapaths, e.g. to connect bridges in system and netdev datapaths.

The following command creates and connects patch ports p0 and p1 and adds them to bridges
br0 and br1, respectively:

ovs-vsctl add-port br0 p0 -- set Interface p0 type=patch options:peer=p1 \
-- add-port br1 p1 -- set Interface p1 type=patch options:peer=p0

options : peer: optional string
The name of the Interface for the other side of the patch. The named Interface’s
own peer option must specify this Interface’s name. That is, the two patch
interfaces must have reversed name and peer values.

PMD (Poll Mode Driver) Options:

Only PMD netdevs support these options.

options : n_rxq: optional string, containing an integer, at least 1
Specifies the maximum number of rx queues to be created for PMD netdev. If not
specified or specified to 0, one rx queue will be created by default. Not supported
by DPDK vHost interfaces.

options : dpdk-devargs: optional string
Specifies the PCI address associated with the port for physical devices, or the
virtual driver to be used for the port when a virtual PMD is intended to be used.
For the latter, the argument string typically takes the form of eth_driver_namex,
where driver_name is a valid virtual DPDK PMD driver name and x is a unique
identifier of your choice for the given port. Only supported by the dpdk port type.

other_config : pmd-rxq-affinity: optional string
Specifies mapping of RX queues of this interface to CPU cores.

Value should be set in the following form:

other_config:pmd-rxq-affinity=<rxq-affinity-list>

where

• <rxq-affinity-list> ::= NULL | <non-empty-list>

• <non-empty-list> ::= <affinity-pair> | <affinity-pair> , <non-empty-list>

• <affinity-pair> ::= <queue-id> : <core-id>

options : xdp-mode: optional string, one of best-effort, generic, native-with-zerocopy, or
native
Specifies the operational mode of the XDP program.

In native-with-zerocopy mode the XDP program is loaded into the device driver with
zero-copy RX and TX enabled. This mode requires device driver support and has the
best performance because there should be no copying of packets.

native is the same as native-with-zerocopy, but without zero-copy capability. This
requires at least one copy between kernel and the userspace. This mode also
requires support from device driver.

In generic case the XDP program in kernel works after skb allocation on early
stages of packet processing inside the network stack. This mode doesn’t require
driver support, but has much lower performance.

best-effort tries to detect and choose the best (fastest) from the available modes
for current interface.

Note that this option is specific to netdev-afxdp. Defaults to best-effort mode.

options : use-need-wakeup: optional string, either true or false
Specifies whether to use need_wakeup feature in afxdp netdev. If enabled, OVS
explicitly wakes up the kernel RX, using poll() syscall and wakes up TX, using
sendto() syscall. For physical devices, this feature improves the performance by
avoiding unnecessary sendto syscalls. Defaults to true if supported by libbpf.

options : vhost-server-path: optional string
The value specifies the path to the socket associated with a vHost User client mode
device that has been or will be created by QEMU. Only supported by
dpdkvhostuserclient interfaces.

options : tx-retries-max: optional string, containing an integer, in range 0 to 32
The value specifies the maximum amount of vhost tx retries that can be made while
trying to send a batch of packets to an interface. Only supported by
dpdkvhostuserclient interfaces.

Default value is 8.

options : n_rxq_desc: optional string, containing an integer, in range 1 to 4,096
Specifies the rx queue size (number rx descriptors) for dpdk ports. The value must
be a power of 2, less than 4096 and supported by the hardware of the device being
configured. If not specified or an incorrect value is specified, 2048 rx
descriptors will be used by default.

options : n_txq_desc: optional string, containing an integer, in range 1 to 4,096
Specifies the tx queue size (number tx descriptors) for dpdk ports. The value must
be a power of 2, less than 4096 and supported by the hardware of the device being
configured. If not specified or an incorrect value is specified, 2048 tx
descriptors will be used by default.

options : dpdk-vf-mac: optional string
Ethernet address to set for this VF interface. If unset then the default MAC
address is used:

• For most drivers, the default MAC address assigned by their hardware.

• For bifurcated drivers, the MAC currently used by the kernel netdevice.

This option may only be used with dpdk VF representors.

options : rx-steering: optional string, either rss+lacp or rss
Configure hardware Rx queue steering policy.

This option takes one of the following values:

rss Distribution of ingress packets in all Rx queues according to the RSS
algorithm. This is the default behaviour.

rss+lacp
Distribution of ingress packets according to the RSS algorithm on all but
the last Rx queue. An extra Rx queue is allocated for LACP packets.

If the user has already configured multiple options:n_rxq on the port, an
additional one will be allocated for the specified protocols. Even if the hardware
cannot satisfy the requested number of requested Rx queues, the last Rx queue will
be used. If only one Rx queue is available or if the hardware does not support the
rte_flow matchers/actions required to redirect the selected protocols, custom
rx-steering will fall back to default rss mode.

This feature is mutually exclusive with other_config:hw-offload as it may conflict
with the offloaded flows. If both are enabled, rx-steering will fall back to
default rss mode.

This option is only applicable to interfaces with type dpdk.

other_config : tx-steering: optional string, either hash or thread
Specifies the Tx steering mode for the interface.

thread enables static (1:1) thread-to-txq mapping when the number of Tx queues is
greater than number of PMD threads, and dynamic (N:1) mapping if equal or lower. In
this mode a single thread can not use more than 1 transmit queue of a given port.

hash enables hash-based Tx steering, which distributes the packets on all the
transmit queues based on their 5-tuples hashes.

Defaults to thread.

EMC (Exact Match Cache) Configuration:

These settings controls behaviour of EMC lookups/insertions for packets received from the
interface.

other_config : emc-enable: optional string, either true or false
Specifies if Exact Match Cache (EMC) should be used while processing packets
received from this interface. If true, other_config:emc-insert-inv-prob will have
effect on this interface.

Defaults to true.

MTU:

The MTU (maximum transmission unit) is the largest amount of data that can fit into a
single Ethernet frame. The standard Ethernet MTU is 1500 bytes. Some physical media and
many kinds of virtual interfaces can be configured with higher MTUs.

A client may change an interface MTU by filling in mtu_request. Open vSwitch then reports
in mtu the currently configured value.

mtu: optional integer
The currently configured MTU for the interface.

This column will be empty for an interface that does not have an MTU as, for
example, some kinds of tunnels do not.

Open vSwitch sets this column’s value, so other clients should treat it as read-
only.

mtu_request: optional integer, at least 1
Requested MTU (Maximum Transmission Unit) for the interface. A client can fill this
column to change the MTU of an interface.

RFC 791 requires every internet module to be able to forward a datagram of 68
octets without further fragmentation. The maximum size of an IP packet is 65535
bytes.

If this is not set and if the interface has internal type, Open vSwitch will change
the MTU to match the minimum of the other interfaces in the bridge.

Interface Status:

Status information about interfaces attached to bridges, updated every 5 seconds. Not all
interfaces have all of these properties; virtual interfaces don’t have a link speed, for
example. Non-applicable columns will have empty values.

admin_state: optional string, either down or up
The administrative state of the physical network link.

link_state: optional string, either down or up
The observed state of the physical network link. This is ordinarily the link’s
carrier status. If the interface’s Port is a bond configured for miimon monitoring,
it is instead the network link’s miimon status.

link_resets: optional integer
The number of times Open vSwitch has observed the link_state of this Interface
change.

link_speed: optional integer
The negotiated speed of the physical network link. Valid values are positive
integers greater than 0.

duplex: optional string, either full or half
The duplex mode of the physical network link.

lacp_current: optional boolean
Boolean value indicating LACP status for this interface. If true, this interface
has current LACP information about its LACP partner. This information may be used
to monitor the health of interfaces in a LACP enabled port. This column will be
empty if LACP is not enabled.

status: map of string-string pairs
Key-value pairs that report port status. Supported status values are type-
dependent; some interfaces may not have a valid status:driver_name, for example.

status : driver_name: optional string
The name of the device driver controlling the network adapter.

status : driver_version: optional string
The version string of the device driver controlling the network adapter.

status : firmware_version: optional string
The version string of the network adapter’s firmware, if available.

status : source_ip: optional string
The source IP address used for an IPv4/IPv6 tunnel end-point, such as gre.

status : tunnel_egress_iface: optional string
Egress interface for tunnels. Currently only relevant for tunnels on Linux systems,
this column will show the name of the interface which is responsible for routing
traffic destined for the configured options:remote_ip. This could be an internal
interface such as a bridge port.

status : tunnel_egress_iface_carrier: optional string, either down or up
Whether carrier is detected on status:tunnel_egress_iface.

dpdk:

DPDK specific interface status options.

status : port_no: optional string
DPDK port ID.

status : numa_id: optional string
NUMA socket ID to which an Ethernet device is connected.

status : min_rx_bufsize: optional string
Minimum size of RX buffer.

status : max_rx_pktlen: optional string
Maximum configurable length of RX pkt.

status : max_rx_queues: optional string
Maximum number of RX queues.

status : max_tx_queues: optional string
Maximum number of TX queues.

status : max_mac_addrs: optional string
Maximum number of MAC addresses.

status : max_hash_mac_addrs: optional string
Maximum number of hash MAC addresses for MTA and UTA.

status : max_vfs: optional string
Maximum number of hash MAC addresses for MTA and UTA. Maximum number of VFs.

status : max_vmdq_pools: optional string
Maximum number of VMDq pools.

status : if_type: optional string
Interface type ID according to IANA ifTYPE MIB definitions.

status : if_descr: optional string
Interface description string.

status : bus_info: optional string
Bus name and bus info such as Vendor ID and Device ID of PCI device.

status : dpdk-vf-mac: optional string
Ethernet address set for this VF interface. Only reported for dpdk VF representors.

status : rx_steering: optional string
Hardware Rx queue steering policy in use.

status : rx_steering_queue: optional string
ID of rx steering queue. Only reported if rx-steering is supported by hardware.

status : rss_queues: optional string
IDs of rss queues. Only reported if rx-steering is supported by hardware.

dpdkvhostuser:

dpdkvhostuser and dpdkvhostuserclient netdev specific interface status information.

status : mode: optional string
client (connecting) or server (listening) in the socket communication.

status : features: optional string
virtio features bitmap as per virtio specification.

status : num_of_vrings: optional string
The number of available virtqueues.

status : numa: optional string
The numa id of the device and guest memory.

status : socket: optional string
The path to the socket used for communication.

status : status: optional string
Status of connection to the device.

status : vring_n_size: optional string
Each virtqueue will have it’s size reported, where n is the virtqueue number from
0..(num_of_vrings-1).

status : userspace-tso: optional string
Whether userspace-tso is enabled or disabled.

Statistics:

Key-value pairs that report interface statistics. The current implementation updates these
counters periodically. The update period is controlled by other_config:stats-update-
interval in the Open_vSwitch table. Future implementations may update them when an
interface is created, when they are queried (e.g. using an OVSDB select operation), and
just before an interface is deleted due to virtual interface hot-unplug or VM shutdown,
and perhaps at other times, but not on any regular periodic basis.

These are the same statistics reported by OpenFlow in its struct ofp_port_stats structure.
If an interface does not support a given statistic, then that pair is omitted.

Statistics: Successful transmit and receive counters:

statistics : rx_packets: optional integer
Number of received packets.

statistics : rx_bytes: optional integer
Number of received bytes.

statistics : tx_packets: optional integer
Number of transmitted packets.

statistics : tx_bytes: optional integer
Number of transmitted bytes.

Statistics: Receive errors:

statistics : rx_dropped: optional integer
Number of packets dropped by RX.

statistics : rx_frame_err: optional integer
Number of frame alignment errors.

statistics : rx_over_err: optional integer
Number of packets with RX overrun.

statistics : rx_crc_err: optional integer
Number of CRC errors.

statistics : rx_errors: optional integer
Total number of receive errors, greater than or equal to the sum of the above.

Statistics: Transmit errors:

statistics : tx_dropped: optional integer
Number of packets dropped by TX.

statistics : collisions: optional integer
Number of collisions.

statistics : tx_errors: optional integer
Total number of transmit errors, greater than or equal to the sum of the above.

Ingress Policing:

These settings control ingress policing for packets received on this interface. On a
physical interface, this limits the rate at which traffic is allowed into the system from
the outside; on a virtual interface (one connected to a virtual machine), this limits the
rate at which the VM is able to transmit.

Policing is a simple form of quality-of-service that simply drops packets received in
excess of the configured rate. Due to its simplicity, policing is usually less accurate
and less effective than egress QoS (which is configured using the QoS and Queue tables).

Policing settings can be set with byte rate or packet rate, and they can be configured
together, in which case they take effect together, that means the smaller speed limit of
them is in effect.

Currently, byte rate policing is implemented on Linux and OVS with DPDK, while packet rate
policing is only implemented on Linux. Both Linux and OVS DPDK implementations use a
simple ``token bucket’’ approach.

Byte rate policing:

• The size of the bucket corresponds to ingress_policing_burst. Initially the
bucket is full.

• Whenever a packet is received, its size (converted to tokens) is compared to
the number of tokens currently in the bucket. If the required number of
tokens are available, they are removed and the packet is forwarded.
Otherwise, the packet is dropped.

• Whenever it is not full, the bucket is refilled with tokens at the rate
specified by ingress_policing_rate.

Packet rate policing:

• The size of the bucket corresponds to ingress_policing_kpkts_burst.
Initially the bucket is full.

• Whenever a packet is received, it will consume one token from the current
bucket. If the token is available in the bucket, it’s removed and the packet
is forwarded. Otherwise, the packet is dropped.

• Whenever it is not full, the bucket is refilled with tokens at the rate
specified by ingress_policing_kpkts_rate.

Policing interacts badly with some network protocols, and especially with fragmented IP
packets. Suppose that there is enough network activity to keep the bucket nearly empty all
the time. Then this token bucket algorithm will forward a single packet every so often,
with the period depending on packet size and on the configured rate. All of the fragments
of an IP packets are normally transmitted back-to-back, as a group. In such a situation,
therefore, only one of these fragments will be forwarded and the rest will be dropped. IP
does not provide any way for the intended recipient to ask for only the remaining
fragments. In such a case there are two likely possibilities for what will happen next:
either all of the fragments will eventually be retransmitted (as TCP will do), in which
case the same problem will recur, or the sender will not realize that its packet has been
dropped and data will simply be lost (as some UDP-based protocols will do). Either way, it
is possible that no forward progress will ever occur.

ingress_policing_rate: integer, at least 0
Maximum rate for data received on this interface, in kbps. Data received faster
than this rate is dropped. Set to 0 (the default) to disable policing.

ingress_policing_kpkts_rate: integer, at least 0
Maximum rate for data received on this interface, in kpps (1 kpps is 1000 pps).
Data received faster than this rate is dropped. Set to 0 (the default) to disable
policing.

ingress_policing_burst: integer, at least 0
Maximum burst size for data received on this interface, in kb. The default burst
size if set to 0 is 8000 kbit. This value has no effect if ingress_policing_rate is
0.

Specifying a larger burst size lets the algorithm be more forgiving, which is
important for protocols like TCP that react severely to dropped packets. The burst
size should be at least the size of the interface’s MTU. Specifying a value that is
numerically at least as large as 80% of ingress_policing_rate helps TCP come closer
to achieving the full rate.

ingress_policing_kpkts_burst: integer, at least 0
Maximum burst size for data received on this interface, in kpkts (1 kpkts is 1000
packets). The default burst size if set to 0 is 16 kpkts. This value has no effect
if ingress_policing_kpkts_rate is 0.

Specifying a larger burst size lets the algorithm be more forgiving, which is
important for protocols like TCP that react severely to dropped packets. Specifying
a value that is numerically at least as large as 80% of ingress_policing_kpkts_rate
helps TCP come closer to achieving the full rate.

Bidirectional Forwarding Detection (BFD):

BFD, defined in RFC 5880 and RFC 5881, allows point-to-point detection of connectivity
failures by occasional transmission of BFD control messages. Open vSwitch implements BFD
to serve as a more popular and standards compliant alternative to CFM.

BFD operates by regularly transmitting BFD control messages at a rate negotiated
independently in each direction. Each endpoint specifies the rate at which it expects to
receive control messages, and the rate at which it is willing to transmit them. By
default, Open vSwitch uses a detection multiplier of three, meaning that an endpoint
signals a connectivity fault if three consecutive BFD control messages fail to arrive. In
the case of a unidirectional connectivity issue, the system not receiving BFD control
messages signals the problem to its peer in the messages it transmits.

The Open vSwitch implementation of BFD aims to comply faithfully with RFC 5880
requirements. Open vSwitch does not implement the optional Authentication or ``Echo Mode’’
features.

OVS 2.13 and earlier intercepted and processed all BFD packets. OVS 2.14 and later only
intercept and process BFD packets destined to a configured BFD instance, and other BFD
packets are made available to the OVS flow table for forwarding.

BFD Configuration:

A controller sets up key-value pairs in the bfd column to enable and configure BFD.

bfd : enable: optional string, either true or false
True to enable BFD on this Interface. If not specified, BFD will not be enabled by
default.

bfd : min_rx: optional string, containing an integer, at least 1
The shortest interval, in milliseconds, at which this BFD session offers to receive
BFD control messages. The remote endpoint may choose to send messages at a slower
rate. Defaults to 1000.

bfd : min_tx: optional string, containing an integer, at least 1
The shortest interval, in milliseconds, at which this BFD session is willing to
transmit BFD control messages. Messages will actually be transmitted at a slower
rate if the remote endpoint is not willing to receive as quickly as specified.
Defaults to 100.

bfd : decay_min_rx: optional string, containing an integer
An alternate receive interval, in milliseconds, that must be greater than or equal
to bfd:min_rx. The implementation switches from bfd:min_rx to bfd:decay_min_rx when
there is no obvious incoming data traffic at the interface, to reduce the CPU and
bandwidth cost of monitoring an idle interface. This feature may be disabled by
setting a value of 0. This feature is reset whenever bfd:decay_min_rx or bfd:min_rx
changes.

bfd : forwarding_if_rx: optional string, either true or false
When true, traffic received on the Interface is used to indicate the capability of
packet I/O. BFD control packets are still transmitted and received. At least one
BFD control packet must be received every 100 * bfd:min_rx amount of time.
Otherwise, even if traffic are received, the bfd:forwarding will be false.

bfd : cpath_down: optional string, either true or false
Set to true to notify the remote endpoint that traffic should not be forwarded to
this system for some reason other than a connectivty failure on the interface being
monitored. The typical underlying reason is ``concatenated path down,’’ that is,
that connectivity beyond the local system is down. Defaults to false.

bfd : check_tnl_key: optional string, either true or false
Set to true to make BFD accept only control messages with a tunnel key of zero. By
default, BFD accepts control messages with any tunnel key.

bfd : bfd_local_src_mac: optional string
Set to an Ethernet address in the form xx:xx:xx:xx:xx:xx to set the MAC used as
source for transmitted BFD packets. The default is the mac address of the BFD
enabled interface.

bfd : bfd_local_dst_mac: optional string
Set to an Ethernet address in the form xx:xx:xx:xx:xx:xx to set the MAC used as
destination for transmitted BFD packets. The default is 00:23:20:00:00:01.

bfd : bfd_remote_dst_mac: optional string
Set to an Ethernet address in the form xx:xx:xx:xx:xx:xx to set the MAC used for
checking the destination of received BFD packets. Packets with different
destination MAC will not be considered as BFD packets. If not specified the
destination MAC address of received BFD packets are not checked.

bfd : bfd_src_ip: optional string
Set to an IPv4 address to set the IP address used as source for transmitted BFD
packets. The default is 169.254.1.1.

bfd : bfd_dst_ip: optional string
Set to an IPv4 address to set the IP address used as destination for transmitted
BFD packets. The default is 169.254.1.0.

bfd : oam: optional string
Some tunnel protocols (such as Geneve) include a bit in the header to indicate that
the encapsulated packet is an OAM frame. By setting this to true, BFD packets will
be marked as OAM if encapsulated in one of these tunnels.

bfd : mult: optional string, containing an integer, in range 1 to 255
The BFD detection multiplier, which defaults to 3. An endpoint signals a
connectivity fault if the given number of consecutive BFD control messages fail to
arrive.

BFD Status:

The switch sets key-value pairs in the bfd_status column to report the status of BFD on
this interface. When BFD is not enabled, with bfd:enable, the switch clears all key-value
pairs from bfd_status.

bfd_status : state: optional string, one of admin_down, down, init, or up
Reports the state of the BFD session. The BFD session is fully healthy and
negotiated if UP.

bfd_status : forwarding: optional string, either true or false
Reports whether the BFD session believes this Interface may be used to forward
traffic. Typically this means the local session is signaling UP, and the remote
system isn’t signaling a problem such as concatenated path down.

bfd_status : diagnostic: optional string
A diagnostic code specifying the local system’s reason for the last change in
session state. The error messages are defined in section 4.1 of [RFC 5880].

bfd_status : remote_state: optional string, one of admin_down, down, init, or up
Reports the state of the remote endpoint’s BFD session.

bfd_status : remote_diagnostic: optional string
A diagnostic code specifying the remote system’s reason for the last change in
session state. The error messages are defined in section 4.1 of [RFC 5880].

bfd_status : flap_count: optional string, containing an integer, at least 0
Counts the number of bfd_status:forwarding flaps since start. A flap is considered
as a change of the bfd_status:forwarding value.

Connectivity Fault Management:

802.1ag Connectivity Fault Management (CFM) allows a group of Maintenance Points (MPs)
called a Maintenance Association (MA) to detect connectivity problems with each other. MPs
within a MA should have complete and exclusive interconnectivity. This is verified by
occasionally broadcasting Continuity Check Messages (CCMs) at a configurable transmission
interval.

According to the 802.1ag specification, each Maintenance Point should be configured out-
of-band with a list of Remote Maintenance Points it should have connectivity to. Open
vSwitch differs from the specification in this area. It simply assumes the link is faulted
if no Remote Maintenance Points are reachable, and considers it not faulted otherwise.

When operating over tunnels which have no in_key, or an in_key of flow. CFM will only
accept CCMs with a tunnel key of zero.

cfm_mpid: optional integer
A Maintenance Point ID (MPID) uniquely identifies each endpoint within a
Maintenance Association. The MPID is used to identify this endpoint to other
Maintenance Points in the MA. Each end of a link being monitored should have a
different MPID. Must be configured to enable CFM on this Interface.

According to the 802.1ag specification, MPIDs can only range between [1, 8191].
However, extended mode (see other_config:cfm_extended) supports eight byte MPIDs.

cfm_flap_count: optional integer
Counts the number of cfm fault flapps since boot. A flap is considered to be a
change of the cfm_fault value.

cfm_fault: optional boolean
Indicates a connectivity fault triggered by an inability to receive heartbeats from
any remote endpoint. When a fault is triggered on Interfaces participating in
bonds, they will be disabled.

Faults can be triggered for several reasons. Most importantly they are triggered
when no CCMs are received for a period of 3.5 times the transmission interval.
Faults are also triggered when any CCMs indicate that a Remote Maintenance Point is
not receiving CCMs but able to send them. Finally, a fault is triggered if a CCM is
received which indicates unexpected configuration. Notably, this case arises when a
CCM is received which advertises the local MPID.

cfm_fault_status : recv: none
Indicates a CFM fault was triggered due to a lack of CCMs received on the
Interface.

cfm_fault_status : rdi: none
Indicates a CFM fault was triggered due to the reception of a CCM with the RDI bit
flagged. Endpoints set the RDI bit in their CCMs when they are not receiving CCMs
themselves. This typically indicates a unidirectional connectivity failure.

cfm_fault_status : maid: none
Indicates a CFM fault was triggered due to the reception of a CCM with a MAID other
than the one Open vSwitch uses. CFM broadcasts are tagged with an identification
number in addition to the MPID called the MAID. Open vSwitch only supports
receiving CCM broadcasts tagged with the MAID it uses internally.

cfm_fault_status : loopback: none
Indicates a CFM fault was triggered due to the reception of a CCM advertising the
same MPID configured in the cfm_mpid column of this Interface. This may indicate a
loop in the network.

cfm_fault_status : overflow: none
Indicates a CFM fault was triggered because the CFM module received CCMs from more
remote endpoints than it can keep track of.

cfm_fault_status : override: none
Indicates a CFM fault was manually triggered by an administrator using an
ovs-appctl command.

cfm_fault_status : interval: none
Indicates a CFM fault was triggered due to the reception of a CCM frame having an
invalid interval.

cfm_remote_opstate: optional string, either down or up
When in extended mode, indicates the operational state of the remote endpoint as
either up or down. See other_config:cfm_opstate.

cfm_health: optional integer, in range 0 to 100
Indicates the health of the interface as a percentage of CCM frames received over
21 other_config:cfm_intervals. The health of an interface is undefined if it is
communicating with more than one cfm_remote_mpids. It reduces if healthy heartbeats
are not received at the expected rate, and gradually improves as healthy heartbeats
are received at the desired rate. Every 21 other_config:cfm_intervals, the health
of the interface is refreshed.

As mentioned above, the faults can be triggered for several reasons. The link
health will deteriorate even if heartbeats are received but they are reported to be
unhealthy. An unhealthy heartbeat in this context is a heartbeat for which either
some fault is set or is out of sequence. The interface health can be 100 only on
receiving healthy heartbeats at the desired rate.

cfm_remote_mpids: set of integers
When CFM is properly configured, Open vSwitch will occasionally receive CCM
broadcasts. These broadcasts contain the MPID of the sending Maintenance Point. The
list of MPIDs from which this Interface is receiving broadcasts from is regularly
collected and written to this column.

other_config : cfm_interval: optional string, containing an integer
The interval, in milliseconds, between transmissions of CFM heartbeats. Three
missed heartbeat receptions indicate a connectivity fault.

In standard operation only intervals of 3, 10, 100, 1,000, 10,000, 60,000, or
600,000 ms are supported. Other values will be rounded down to the nearest value on
the list. Extended mode (see other_config:cfm_extended) supports any interval up to
65,535 ms. In either mode, the default is 1000 ms.

We do not recommend using intervals less than 100 ms.

other_config : cfm_extended: optional string, either true or false
When true, the CFM module operates in extended mode. This causes it to use a
nonstandard destination address to avoid conflicting with compliant implementations
which may be running concurrently on the network. Furthermore, extended mode
increases the accuracy of the cfm_interval configuration parameter by breaking wire
compatibility with 802.1ag compliant implementations. And extended mode allows
eight byte MPIDs. Defaults to false.

other_config : cfm_demand: optional string, either true or false
When true, and other_config:cfm_extended is true, the CFM module operates in demand
mode. When in demand mode, traffic received on the Interface is used to indicate
liveness. CCMs are still transmitted and received. At least one CCM must be
received every 100 * other_config:cfm_interval amount of time. Otherwise, even if
traffic are received, the CFM module will raise the connectivity fault.

Demand mode has a couple of caveats:

• To ensure that ovs-vswitchd has enough time to pull statistics from the
datapath, the fault detection interval is set to 3.5 *
MAX(other_config:cfm_interval, 500) ms.

• To avoid ambiguity, demand mode disables itself when there are multiple
remote maintenance points.

• If the Interface is heavily congested, CCMs containing the
other_config:cfm_opstate status may be dropped causing changes in the
operational state to be delayed. Similarly, if CCMs containing the RDI bit
are not received, unidirectional link failures may not be detected.

other_config : cfm_opstate: optional string, either down or up
When down, the CFM module marks all CCMs it generates as operationally down without
triggering a fault. This allows remote maintenance points to choose not to forward
traffic to the Interface on which this CFM module is running. Currently, in Open
vSwitch, the opdown bit of CCMs affects Interfaces participating in bonds, and the
bundle OpenFlow action. This setting is ignored when CFM is not in extended mode.
Defaults to up.

other_config : cfm_ccm_vlan: optional string, containing an integer, in range 1 to 4,095
When set, the CFM module will apply a VLAN tag to all CCMs it generates with the
given value. May be the string random in which case each CCM will be tagged with a
different randomly generated VLAN.

other_config : cfm_ccm_pcp: optional string, containing an integer, in range 1 to 7
When set, the CFM module will apply a VLAN tag to all CCMs it generates with the
given PCP value, the VLAN ID of the tag is governed by the value of
other_config:cfm_ccm_vlan. If other_config:cfm_ccm_vlan is unset, a VLAN ID of zero
is used.

Bonding Configuration:

other_config : lacp-port-id: optional string, containing an integer, in range 1 to 65,535
The LACP port ID of this Interface. Port IDs are used in LACP negotiations to
identify individual ports participating in a bond.

other_config : lacp-port-priority: optional string, containing an integer, in range 1 to
65,535
The LACP port priority of this Interface. In LACP negotiations Interfaces with
numerically lower priorities are preferred for aggregation.

other_config : lacp-aggregation-key: optional string, containing an integer, in range 1 to
65,535
The LACP aggregation key of this Interface. Interfaces with different aggregation
keys may not be active within a given Port at the same time.

Virtual Machine Identifiers:

These key-value pairs specifically apply to an interface that represents a virtual
Ethernet interface connected to a virtual machine. These key-value pairs should not be
present for other types of interfaces. Keys whose names end in -uuid have values that
uniquely identify the entity in question.

external_ids : attached-mac: optional string
The MAC address programmed into the ``virtual hardware’’ for this interface, in the
form xx:xx:xx:xx:xx:xx.

external_ids : iface-id: optional string
A system-unique identifier for the interface.

external_ids : iface-status: optional string, either active or inactive
Hypervisors may sometimes have more than one interface associated with a given
external_ids:iface-id, only one of which is actually in use at a given time. For
example, in some circumstances hypervisor may have both a ``tap’’ and a ``vif’’
interface for a single external_ids:iface-id, but only uses one of them at a time.
A hypervisor that behaves this way must mark the currently in use interface active
and the others inactive. A hypervisor that never has more than one interface for a
given external_ids:iface-id may mark that interface active or omit
external_ids:iface-status entirely.

During VM migration, a given external_ids:iface-id might transiently be marked
active on two different hypervisors. That is, active means that this
external_ids:iface-id is the active instance within a single hypervisor, not in a
broader scope. There is one exception: some hypervisors support ``migration’’ from
a given hypervisor to itself (most often for test purposes). During such a
``migration,’’ two instances of a single external_ids:iface-id might both be
briefly marked active on a single hypervisor.

external_ids : vm-id: optional string
The VM to which this interface belongs.

Auto Attach Configuration:

Auto Attach configuration for a particular interface.

lldp : enable: optional string, either true or false
True to enable LLDP on this Interface. If not specified, LLDP will be disabled by
default.

Flow control Configuration:

Ethernet flow control defined in IEEE 802.1Qbb provides link level flow control using MAC
pause frames. Implemented only for interfaces with type dpdk.

options : rx-flow-ctrl: optional string, either true or false
Set to true to enable Rx flow control on physical ports. By default, Rx flow
control is disabled.

options : tx-flow-ctrl: optional string, either true or false
Set to true to enable Tx flow control on physical ports. By default, Tx flow
control is disabled.

options : flow-ctrl-autoneg: optional string, either true or false
Set to true to enable flow control auto negotiation on physical ports. By default,
auto-neg is disabled.

Link State Change detection mode:

options : dpdk-lsc-interrupt: optional string, either true or false
Set this value to true to configure interrupt mode for Link State Change (LSC)
detection instead of poll mode for the DPDK interface.

If this value is not set, poll mode is configured.

This parameter has an effect only on netdev dpdk interfaces.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

other_config: map of string-string pairs

external_ids: map of string-string pairs

Flow_Table TABLE

Configuration for a particular OpenFlow table.

Summary:
name optional string
Eviction Policy:
flow_limit optional integer, at least 0
overflow_policy optional string, either evict or refuse
groups set of strings
Classifier Optimization:
prefixes set of up to 3 strings
Common Columns:
external_ids map of string-string pairs

Details:
name: optional string
The table’s name. Set this column to change the name that controllers will receive
when they request table statistics, e.g. ovs-ofctl dump-tables. The name does not
affect switch behavior.

Eviction Policy:

Open vSwitch supports limiting the number of flows that may be installed in a flow table,
via the flow_limit column. When adding a flow would exceed this limit, by default Open
vSwitch reports an error, but there are two ways to configure Open vSwitch to instead
delete (``evict’’) a flow to make room for the new one:

• Set the overflow_policy column to evict.

• Send an OpenFlow 1.4+ ``table mod request’’ to enable eviction for the flow
table (e.g. ovs-ofctl -O OpenFlow14 mod-table br0 0 evict to enable eviction
on flow table 0 of bridge br0).

When a flow must be evicted due to overflow, the flow to evict is chosen through an
approximation of the following algorithm. This algorithm is used regardless of how
eviction was enabled:

1. Divide the flows in the table into groups based on the values of the fields or
subfields specified in the groups column, so that all of the flows in a given
group have the same values for those fields. If a flow does not specify a given
field, that field’s value is treated as 0. If groups is empty, then all of the
flows in the flow table are treated as a single group.

2. Consider the flows in the largest group, that is, the group that contains the
greatest number of flows. If two or more groups all have the same largest
number of flows, consider the flows in all of those groups.

3. If the flows under consideration have different importance values, eliminate
from consideration any flows except those with the lowest importance.
(``Importance,’’ a 16-bit integer value attached to each flow, was introduced
in OpenFlow 1.4. Flows inserted with older versions of OpenFlow always have an
importance of 0.)

4. Among the flows under consideration, choose the flow that expires soonest for
eviction.

The eviction process only considers flows that have an idle timeout or a hard timeout.
That is, eviction never deletes permanent flows. (Permanent flows do count against
flow_limit.)

flow_limit: optional integer, at least 0
If set, limits the number of flows that may be added to the table. Open vSwitch may
limit the number of flows in a table for other reasons, e.g. due to hardware
limitations or for resource availability or performance reasons.

overflow_policy: optional string, either evict or refuse
Controls the switch’s behavior when an OpenFlow flow table modification request
would add flows in excess of flow_limit. The supported values are:

refuse Refuse to add the flow or flows. This is also the default policy when
overflow_policy is unset.

evict Delete a flow chosen according to the algorithm described above.

groups: set of strings
When overflow_policy is evict, this controls how flows are chosen for eviction when
the flow table would otherwise exceed flow_limit flows. Its value is a set of NXM
fields or sub-fields, each of which takes one of the forms field[] or
field[start..end], e.g. NXM_OF_IN_PORT[]. Please see meta-flow.h for a complete
list of NXM field names.

Open vSwitch ignores any invalid or unknown field specifications.

When eviction is not enabled, via overflow_policy or an OpenFlow 1.4+ ``table
mod,’’ this column has no effect.

Classifier Optimization:

prefixes: set of up to 3 strings
This string set specifies which fields should be used for address prefix tracking.
Prefix tracking allows the classifier to skip rules with longer than necessary
prefixes, resulting in better wildcarding for datapath flows.

Prefix tracking may be beneficial when a flow table contains matches on IP address
fields with different prefix lengths. For example, when a flow table contains IP
address matches on both full addresses and proper prefixes, the full address
matches will typically cause the datapath flow to un-wildcard the whole address
field (depending on flow entry priorities). In this case each packet with a
different address gets handed to the userspace for flow processing and generates
its own datapath flow. With prefix tracking enabled for the address field in
question packets with addresses matching shorter prefixes would generate datapath
flows where the irrelevant address bits are wildcarded, allowing the same datapath
flow to handle all the packets within the prefix in question. In this case many
userspace upcalls can be avoided and the overall performance can be better.

This is a performance optimization only, so packets will receive the same treatment
with or without prefix tracking.

The supported fields are: tun_id, tun_src, tun_dst, tun_ipv6_src, tun_ipv6_dst,
nw_src, nw_dst (or aliases ip_src and ip_dst), ipv6_src, and ipv6_dst. (Using this
feature for tun_id would only make sense if the tunnel IDs have prefix structure
similar to IP addresses.)

By default, the prefixes=ip_dst,ip_src are used on each flow table. This instructs
the flow classifier to track the IP destination and source addresses used by the
rules in this specific flow table.

The keyword none is recognized as an explicit override of the default values,
causing no prefix fields to be tracked.

To set the prefix fields, the flow table record needs to exist:

ovs-vsctl set Bridge br0 flow_tables:0=@N1 -- --id=@N1 create Flow_Table
name=table0
Creates a flow table record for the OpenFlow table number 0.

ovs-vsctl set Flow_Table table0 prefixes=ip_dst,ip_src
Enables prefix tracking for IP source and destination address fields.

There is a maximum number of fields that can be enabled for any one flow table.
Currently this limit is 3.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

QoS TABLE

Quality of Service (QoS) configuration for each Port that references it.

Summary:
type string
queues map of integer-Queue pairs, key in range 0 to 4,294,967,295
Configuration for linux-htb and linux-hfsc:
other_config : max-rate optional string, containing an integer
Configuration for egress-policer QoS:
other_config : cir optional string, containing an integer
other_config : cbs optional string, containing an integer
other_config : eir optional string, containing an integer
other_config : ebs optional string, containing an integer
Configuration for linux-sfq:
other_config : perturb optional string, containing an integer
other_config : quantum optional string, containing an integer
Configuration for linux-netem:
other_config : latency optional string, containing an integer
other_config : limit optional string, containing an integer
other_config : loss optional string, containing an integer
other_config : jitter optional string, containing an integer
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs

Details:
type: string
The type of QoS to implement. The currently defined types are listed below:

linux-htb
Linux ``hierarchy token bucket’’ classifier. See tc-htb(8) (also at
http://linux.die.net/man/8/tc-htb) and the HTB manual
(http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm) for information on how
this classifier works and how to configure it.

linux-hfsc
Linux "Hierarchical Fair Service Curve" classifier. See
http://linux-ip.net/articles/hfsc.en/ for information on how this classifier
works.

linux-sfq
Linux ``Stochastic Fairness Queueing’’ classifier. See tc-sfq(8) (also at
http://linux.die.net/man/8/tc-sfq) for information on how this classifier
works.

linux-codel
Linux ``Controlled Delay’’ classifier. See tc-codel(8) (also at
http://man7.org/linux/man-pages/man8/tc-codel.8.html) for information on how
this classifier works.

linux-fq_codel
Linux ``Fair Queuing with Controlled Delay’’ classifier. See tc-fq_codel(8)
(also at http://man7.org/linux/man-pages/man8/tc-fq_codel.8.html) for
information on how this classifier works.

linux-netem
Linux ``Network Emulator’’ classifier. See tc-netem(8) (also at
http://man7.org/linux/man-pages/man8/tc-netem.8.html) for information on how
this classifier works.

linux-noop
Linux ``No operation.’’ By default, Open vSwitch manages quality of service
on all of its configured ports. This can be helpful, but sometimes
administrators prefer to use other software to manage QoS. This type
prevents Open vSwitch from changing the QoS configuration for a port.

egress-policer
A DPDK egress policer algorithm using the DPDK rte_meter library. The
rte_meter library provides an implementation which allows the metering and
policing of traffic. The implementation in OVS essentially creates a single
token bucket used to police traffic. It should be noted that when the
rte_meter is configured as part of QoS there will be a performance overhead
as the rte_meter itself will consume CPU cycles in order to police traffic.
These CPU cycles ordinarily are used for packet proccessing. As such the
drop in performance will be noticed in terms of overall aggregate traffic
throughput.

trtcm-policer
A DPDK egress policer algorithm using RFC 4115’s Two-Rate, Three-Color
marker. It’s a two-level hierarchical policer which first does a color-blind
marking of the traffic at the queue level, followed by a color-aware marking
at the port level. At the end traffic marked as Green or Yellow is
forwarded, Red is dropped. For details on how traffic is marked, see RFC
4115. If the ``default queue’’, 0, is not configured it’s automatically
created with the same other_config values as the physical port.

queues: map of integer-Queue pairs, key in range 0 to 4,294,967,295
A map from queue numbers to Queue records. The supported range of queue numbers
depend on type. The queue numbers are the same as the queue_id used in OpenFlow in
struct ofp_action_enqueue and other structures.

Queue 0 is the ``default queue.’’ It is used by OpenFlow output actions when no
specific queue has been set. When no configuration for queue 0 is present, it is
automatically configured as if a Queue record with empty dscp and other_config
columns had been specified. (Before version 1.6, Open vSwitch would leave queue 0
unconfigured in this case. With some queuing disciplines, this dropped all packets
destined for the default queue.)

Configuration for linux-htb and linux-hfsc:

The linux-htb and linux-hfsc classes support the following key-value pair:

other_config : max-rate: optional string, containing an integer
Maximum rate shared by all queued traffic, in bit/s. Optional. If not specified,
for physical interfaces, the default is the link rate. For other interfaces or if
the link rate cannot be determined, the default is currently 10 Gbps.

Configuration for egress-policer QoS:

QoS type egress-policer provides egress policing for userspace port types with DPDK. It
has the following key-value pairs defined.

other_config : cir: optional string, containing an integer
The Committed Information Rate (CIR) is measured in bytes of IP packets per second,
i.e. it includes the IP header, but not link specific (e.g. Ethernet) headers. This
represents the bytes per second rate at which the token bucket will be updated. The
cir value is calculated by (pps x packet data size). For example assuming a user
wishes to limit a stream consisting of 64 byte packets to 1 million packets per
second the CIR would be set to to to 46000000. This value can be broken into
’1,000,000 x 46’. Where 1,000,000 is the policing rate for the number of packets
per second and 46 represents the size of the packet data for a 64 bytes IP packet
without 14 bytes Ethernet and 4 bytes FCS header.

other_config : cbs: optional string, containing an integer
The Committed Burst Size (CBS) is measured in bytes and represents a token bucket.
At a minimum this value should be be set to the expected largest size packet in the
traffic stream. In practice larger values may be used to increase the size of the
token bucket. If a packet can be transmitted then the cbs will be decremented by
the number of bytes/tokens of the packet. If there are not enough tokens in the cbs
bucket the packet will be dropped.

other_config : eir: optional string, containing an integer
The Excess Information Rate (EIR) is measured in bytes of IP packets per second,
i.e. it includes the IP header, but not link specific (e.g. Ethernet) headers. This
represents the bytes per second rate at which the token bucket will be updated. The
eir value is calculated by (pps x packet data size). For example assuming a user
wishes to limit a stream consisting of 64 byte packets to 1 million packets per
second the EIR would be set to to to 46000000. This value can be broken into
’1,000,000 x 46’. Where 1,000,000 is the policing rate for the number of packets
per second and 46 represents the size of the packet data for a 64 bytes IP packet
without 14 bytes Ethernet and 4 bytes FCS header.

other_config : ebs: optional string, containing an integer
The Excess Burst Size (EBS) is measured in bytes and represents a token bucket. At
a minimum this value should be be set to the expected largest size packet in the
traffic stream. In practice larger values may be used to increase the size of the
token bucket. If a packet can be transmitted then the ebs will be decremented by
the number of bytes/tokens of the packet. If there are not enough tokens in the cbs
bucket the packet might be dropped.

Configuration for linux-sfq:

The linux-sfq QoS supports the following key-value pairs:

other_config : perturb: optional string, containing an integer
Number of seconds between consecutive perturbations in hashing algorithm. Different
flows can end up in the same hash bucket causing unfairness. Perturbation’s goal is
to remove possible unfairness. The default and recommended value is 10. Too low a
value is discouraged because each perturbation can cause packet reordering.

other_config : quantum: optional string, containing an integer
Number of bytes linux-sfq QoS can dequeue in one turn in round-robin from one flow.
The default and recommended value is equal to interface’s MTU.

Configuration for linux-netem:

The linux-netem QoS supports the following key-value pairs:

other_config : latency: optional string, containing an integer
Adds the chosen delay to the packets outgoing to chosen network interface. The
latency value expressed in us.

other_config : limit: optional string, containing an integer
Maximum number of packets the qdisc may hold queued at a time. The default value is
1000.

other_config : loss: optional string, containing an integer
Adds an independent loss probability to the packets outgoing from the chosen
network interface.

other_config : jitter: optional string, containing an integer
Adds the provided jitter to the latency outgoing to the chosen network interface.
The jitter value expressed in us.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

other_config: map of string-string pairs

external_ids: map of string-string pairs

Queue TABLE

       A  configuration  for  a  port  output queue, used in configuring Quality of Service (QoS)
       features. May be referenced by queues column in QoS table.

   Summary:
       dscp                          optional integer, in range 0 to 63
       Configuration for linux-htb QoS:
         other_config : min-rate     optional string, containing an integer, at least 1
         other_config : max-rate     optional string, containing an integer, at least 1
         other_config : burst        optional string, containing an integer, at least 1
         other_config : priority     optional string,  containing  an  integer,  in  range  0  to
                                     4,294,967,295
       Configuration for linux-hfsc QoS:
         other_config : min-rate     optional string, containing an integer, at least 1
         other_config : max-rate     optional string, containing an integer, at least 1
       Common Columns:
         other_config                map of string-string pairs
         external_ids                map of string-string pairs

   Details:
       dscp: optional integer, in range 0 to 63
              If set, Open vSwitch will mark all traffic egressing this Queue with the given DSCP
              bits. Traffic egressing the default Queue is  only  marked  if  it  was  explicitly
              selected as the Queue at the time the packet was output. If unset, the DSCP bits of
              traffic egressing this Queue will remain unchanged.

     Configuration for linux-htb QoS:

       QoS type linux-htb may use queue_ids less than 61440. It has the following key-value pairs
       defined.

       other_config : min-rate: optional string, containing an integer, at least 1
              Minimum guaranteed bandwidth, in bit/s.

       other_config : max-rate: optional string, containing an integer, at least 1
              Maximum  allowed bandwidth, in bit/s. Optional. If specified, the queue’s rate will
              not be allowed  to  exceed  the  specified  value,  even  if  excess  bandwidth  is
              available. If unspecified, defaults to no limit.

       other_config : burst: optional string, containing an integer, at least 1
              Burst  size,  in  bits.  This is the maximum amount of ``credits’’ that a queue can
              accumulate while it is idle. Optional.  Details  of  the  linux-htb  implementation
              require a minimum burst size, so a too-small burst will be silently ignored.

       other_config   :  priority:  optional  string,  containing  an  integer,  in  range  0  to
       4,294,967,295
              A queue with a smaller priority will receive all the excess bandwidth that  it  can
              use  before  a queue with a larger value receives any. Specific priority values are
              unimportant; only relative ordering matters. Defaults to 0 if unspecified.

     Configuration for linux-hfsc QoS:

       QoS type linux-hfsc may use queue_ids less than 61440.  It  has  the  following  key-value
       pairs defined.

       other_config : min-rate: optional string, containing an integer, at least 1
              Minimum guaranteed bandwidth, in bit/s.

       other_config : max-rate: optional string, containing an integer, at least 1
              Maximum  allowed bandwidth, in bit/s. Optional. If specified, the queue’s rate will
              not be allowed  to  exceed  the  specified  value,  even  if  excess  bandwidth  is
              available. If unspecified, defaults to no limit.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       other_config: map of string-string pairs

       external_ids: map of string-string pairs

Mirror TABLE

A port mirror within a Bridge.

A port mirror configures a bridge to send selected frames to special ``mirrored’’ ports,
in addition to their normal destinations. Mirroring traffic may also be referred to as
SPAN or RSPAN, depending on how the mirrored traffic is sent.

When a packet enters an Open vSwitch bridge, it becomes eligible for mirroring based on
its ingress port and VLAN. As the packet travels through the flow tables, each time it is
output to a port, it becomes eligible for mirroring based on the egress port and VLAN. In
Open vSwitch 2.5 and later, mirroring occurs just after a packet first becomes eligible,
using the packet as it exists at that point; in Open vSwitch 2.4 and earlier, mirroring
occurs only after a packet has traversed all the flow tables, using the original packet as
it entered the bridge. This makes a difference only when the flow table modifies the
packet: in Open vSwitch 2.4, the modifications are never visible to mirrors, whereas in
Open vSwitch 2.5 and later modifications made before the first output that makes it
eligible for mirroring to a particular destination are visible.

A packet that enters an Open vSwitch bridge is mirrored to a particular destination only
once, even if it is eligible for multiple reasons. For example, a packet would be mirrored
to a particular output_port only once, even if it is selected for mirroring to that port
by select_dst_port and select_src_port in the same or different Mirror records.

Summary:
name string
Selecting Packets for Mirroring:
select_all boolean
select_dst_port set of weak reference to Ports
select_src_port set of weak reference to Ports
select_vlan set of up to 4,096 integers, in range 0 to 4,095
Mirroring Destination Configuration:
output_port optional weak reference to Port
output_vlan optional integer, in range 1 to 4,095
snaplen optional integer, in range 14 to 65,535
Statistics: Mirror counters:
statistics : tx_packets optional integer
statistics : tx_bytes optional integer
Common Columns:
external_ids map of string-string pairs

Details:
name: string
Arbitrary identifier for the Mirror.

Selecting Packets for Mirroring:

To be selected for mirroring, a given packet must enter or leave the bridge through a
selected port and it must also be in one of the selected VLANs.

select_all: boolean
If true, every packet arriving or departing on any port is selected for mirroring.

select_dst_port: set of weak reference to Ports
Ports on which departing packets are selected for mirroring.

select_src_port: set of weak reference to Ports
Ports on which arriving packets are selected for mirroring.

select_vlan: set of up to 4,096 integers, in range 0 to 4,095
VLANs on which packets are selected for mirroring. An empty set selects packets on
all VLANs.

Mirroring Destination Configuration:

These columns are mutually exclusive. Exactly one of them must be nonempty.

output_port: optional weak reference to Port
Output port for selected packets, if nonempty.

Specifying a port for mirror output reserves that port exclusively for mirroring.
No frames other than those selected for mirroring via this column will be forwarded
to the port, and any frames received on the port will be discarded.

The output port may be any kind of port supported by Open vSwitch. It may be, for
example, a physical port (sometimes called SPAN) or a GRE tunnel.

output_vlan: optional integer, in range 1 to 4,095
Output VLAN for selected packets, if nonempty.

The frames will be sent out all ports that trunk output_vlan, as well as any ports
with implicit VLAN output_vlan. When a mirrored frame is sent out a trunk port, the
frame’s VLAN tag will be set to output_vlan, replacing any existing tag; when it is
sent out an implicit VLAN port, the frame will not be tagged. This type of
mirroring is sometimes called RSPAN.

See the documentation for other_config:forward-bpdu in the Interface table for a
list of destination MAC addresses which will not be mirrored to a VLAN to avoid
confusing switches that interpret the protocols that they represent.

Please note: Mirroring to a VLAN can disrupt a network that contains unmanaged
switches. Consider an unmanaged physical switch with two ports: port 1, connected
to an end host, and port 2, connected to an Open vSwitch configured to mirror
received packets into VLAN 123 on port 2. Suppose that the end host sends a packet
on port 1 that the physical switch forwards to port 2. The Open vSwitch forwards
this packet to its destination and then reflects it back on port 2 in VLAN 123.
This reflected packet causes the unmanaged physical switch to replace the MAC
learning table entry, which correctly pointed to port 1, with one that incorrectly
points to port 2. Afterward, the physical switch will direct packets destined for
the end host to the Open vSwitch on port 2, instead of to the end host on port 1,
disrupting connectivity. If mirroring to a VLAN is desired in this scenario, then
the physical switch must be replaced by one that learns Ethernet addresses on a
per-VLAN basis. In addition, learning should be disabled on the VLAN containing
mirrored traffic. If this is not done then intermediate switches will learn the MAC
address of each end host from the mirrored traffic. If packets being sent to that
end host are also mirrored, then they will be dropped since the switch will attempt
to send them out the input port. Disabling learning for the VLAN will cause the
switch to correctly send the packet out all ports configured for that VLAN. If Open
vSwitch is being used as an intermediate switch, learning can be disabled by adding
the mirrored VLAN to flood_vlans in the appropriate Bridge table or tables.

Mirroring to a GRE tunnel has fewer caveats than mirroring to a VLAN and should
generally be preferred.

snaplen: optional integer, in range 14 to 65,535
Maximum per-packet number of bytes to mirror.

A mirrored packet with size larger than snaplen will be truncated in datapath to
snaplen bytes before sending to the mirror output port. If omitted, packets are not
truncated.

Statistics: Mirror counters:

Key-value pairs that report mirror statistics. The update period is controlled by
other_config:stats-update-interval in the Open_vSwitch table.

statistics : tx_packets: optional integer
Number of packets transmitted through this mirror.

statistics : tx_bytes: optional integer
Number of bytes transmitted through this mirror.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

Controller TABLE

An OpenFlow controller.

Summary:
Core Features:
type optional string, either primary or service
target string
connection_mode optional string, either in-band or out-of-band
Controller Failure Detection and Handling:
max_backoff optional integer, at least 1,000
inactivity_probe optional integer
Asynchronous Messages:
enable_async_messages optional boolean
Controller Rate Limiting:
controller_queue_size optional integer, in range 1 to 512
controller_rate_limit optional integer, at least 100
controller_burst_limit optional integer, at least 25
Controller Rate Limiting Statistics:
status : packet-in-TYPE-bypassed
optional string, containing an integer, at least 0
status : packet-in-TYPE-queued
optional string, containing an integer, at least 0
status : packet-in-TYPE-dropped
optional string, containing an integer, at least 0
status : packet-in-TYPE-backlog
optional string, containing an integer, at least 0
Additional In-Band Configuration:
local_ip optional string
local_netmask optional string
local_gateway optional string
Controller Status:
is_connected boolean
role optional string, one of master, other, or slave
status : last_error optional string
status : state optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE,
or VOID
status : sec_since_connect optional string, containing an integer, at least 0
status : sec_since_disconnect
optional string, containing an integer, at least 1
Connection Parameters:
other_config : dscp optional string, containing an integer
Common Columns:
external_ids map of string-string pairs
other_config map of string-string pairs

Details:
Core Features:

type: optional string, either primary or service
Open vSwitch supports two kinds of OpenFlow controllers. A bridge may have any
number of each kind:

Primary controllers
This is the kind of controller envisioned by the OpenFlow specifications.
Usually, a primary controller implements a network policy by taking charge
of the switch’s flow table.

The fail_mode column in the Bridge table applies to primary controllers.

When multiple primary controllers are configured, Open vSwitch connects to
all of them simultaneously. OpenFlow provides few facilities to allow
multiple controllers to coordinate in interacting with a single switch, so
more than one primary controller should be specified only if the controllers
are themselves designed to coordinate with each other.

Service controllers
These kinds of OpenFlow controller connections are intended for occasional
support and maintenance use, e.g. with ovs-ofctl. Usually a service
controller connects only briefly to inspect or modify some of a switch’s
state.

The fail_mode column in the Bridge table does not apply to service
controllers.

By default, Open vSwitch treats controllers with active connection methods as
primary controllers and those with passive connection methods as service
controllers. Set this column to the desired type to override this default.

target: string
Connection method for controller.

The following active connection methods are currently supported:

ssl:host[:port]
The specified SSL port on the host at the given host, which can either be a
DNS name (if built with unbound library) or an IP address. The ssl column in
the Open_vSwitch table must point to a valid SSL configuration when this
form is used.

If port is not specified, it defaults to 6653.

SSL support is an optional feature that is not always built as part of Open
vSwitch.

tcp:host[:port]
The specified TCP port on the host at the given host, which can either be a
DNS name (if built with unbound library) or an IP address (IPv4 or IPv6). If
host is an IPv6 address, wrap it in square brackets, e.g. tcp:[::1]:6653.

If port is not specified, it defaults to 6653.

The following passive connection methods are currently supported:

pssl:[port][:host]
Listens for SSL connections on the specified TCP port. If host, which can
either be a DNS name (if built with unbound library) or an IP address, is
specified, then connections are restricted to the resolved or specified
local IP address (either IPv4 or IPv6). If host is an IPv6 address, wrap it
in square brackets, e.g. pssl:6653:[::1].

If port is not specified, it defaults to 6653. If host is not specified then
it listens only on IPv4 (but not IPv6) addresses. The ssl column in the
Open_vSwitch table must point to a valid SSL configuration when this form is
used.

If port is not specified, it currently to 6653.

SSL support is an optional feature that is not always built as part of Open
vSwitch.

ptcp:[port][:host]
Listens for connections on the specified TCP port. If host, which can either
be a DNS name (if built with unbound library) or an IP address, is
specified, then connections are restricted to the resolved or specified
local IP address (either IPv4 or IPv6). If host is an IPv6 address, wrap it
in square brackets, e.g. ptcp:6653:[::1]. If host is not specified then it
listens only on IPv4 addresses.

If port is not specified, it defaults to 6653.

When multiple controllers are configured for a single bridge, the target values
must be unique. Duplicate target values yield unspecified results.

connection_mode: optional string, either in-band or out-of-band
If it is specified, this setting must be one of the following strings that
describes how Open vSwitch contacts this OpenFlow controller over the network:

in-band
In this mode, this controller’s OpenFlow traffic travels over the bridge
associated with the controller. With this setting, Open vSwitch allows
traffic to and from the controller regardless of the contents of the
OpenFlow flow table. (Otherwise, Open vSwitch would never be able to connect
to the controller, because it did not have a flow to enable it.) This is the
most common connection mode because it is not necessary to maintain two
independent networks.

out-of-band
In this mode, OpenFlow traffic uses a control network separate from the
bridge associated with this controller, that is, the bridge does not use any
of its own network devices to communicate with the controller. The control
network must be configured separately, before or after ovs-vswitchd is
started.

If not specified, the default is implementation-specific.

Controller Failure Detection and Handling:

max_backoff: optional integer, at least 1,000
Maximum number of milliseconds to wait between connection attempts. Default is
implementation-specific.

inactivity_probe: optional integer
Maximum number of milliseconds of idle time on connection to controller before
sending an inactivity probe message. If Open vSwitch does not communicate with the
controller for the specified number of seconds, it will send a probe. If a response
is not received for the same additional amount of time, Open vSwitch assumes the
connection has been broken and attempts to reconnect. Default is implementation-
specific. A value of 0 disables inactivity probes.

Asynchronous Messages:

OpenFlow switches send certain messages to controllers spontanenously, that is, not in
response to any request from the controller. These messages are called ``asynchronous
messages.’’ These columns allow asynchronous messages to be limited or disabled to ensure
the best use of network resources.

enable_async_messages: optional boolean
The OpenFlow protocol enables asynchronous messages at time of connection
establishment, which means that a controller can receive asynchronous messages,
potentially many of them, even if it turns them off immediately after connecting.
Set this column to false to change Open vSwitch behavior to disable, by default,
all asynchronous messages. The controller can use the NXT_SET_ASYNC_CONFIG Nicira
extension to OpenFlow to turn on any messages that it does want to receive, if any.

Controller Rate Limiting:

A switch can forward packets to a controller over the OpenFlow protocol. Forwarding
packets this way at too high a rate can overwhelm a controller, frustrate use of the
OpenFlow connection for other purposes, increase the latency of flow setup, and use an
unreasonable amount of bandwidth. Therefore, Open vSwitch supports limiting the rate of
packet forwarding to a controller.

There are two main reasons in OpenFlow for a packet to be sent to a controller: either the
packet ``misses’’ in the flow table, that is, there is no matching flow, or a flow table
action says to send the packet to the controller. Open vSwitch limits the rate of each
kind of packet separately at the configured rate. Therefore, the actual rate that packets
are sent to the controller can be up to twice the configured rate, when packets are sent
for both reasons.

This feature is specific to forwarding packets over an OpenFlow connection. It is not
general-purpose QoS. See the QoS table for quality of service configuration, and
ingress_policing_rate in the Interface table for ingress policing configuration.

controller_queue_size: optional integer, in range 1 to 512
This sets the maximum size of the queue of packets that need to be sent to this
OpenFlow controller. The value must be less than 512. If not specified the queue
size is limited to the value set for the management controller in
other_config:controller-queue-size if present or 100 packets by default. Note:
increasing the queue size might have a negative impact on latency.

controller_rate_limit: optional integer, at least 100
The maximum rate at which the switch will forward packets to the OpenFlow
controller, in packets per second. If no value is specified, rate limiting is
disabled.

controller_burst_limit: optional integer, at least 25
When a high rate triggers rate-limiting, Open vSwitch queues packets to the
controller for each port and transmits them to the controller at the configured
rate. This value limits the number of queued packets. Ports on a bridge share the
packet queue fairly.

This value has no effect unless controller_rate_limit is configured. The current
default when this value is not specified is one-quarter of controller_rate_limit,
meaning that queuing can delay forwarding a packet to the controller by up to 250
ms.

Controller Rate Limiting Statistics:

These values report the effects of rate limiting. Their values are relative to
establishment of the most recent OpenFlow connection, or since rate limiting was enabled,
whichever happened more recently. Each consists of two values, one with TYPE replaced by
miss for rate limiting flow table misses, and the other with TYPE replaced by action for
rate limiting packets sent by OpenFlow actions.

These statistics are reported only when controller rate limiting is enabled.

status : packet-in-TYPE-bypassed: optional string, containing an integer, at least 0
Number of packets sent directly to the controller, without queuing, because the
rate did not exceed the configured maximum.

status : packet-in-TYPE-queued: optional string, containing an integer, at least 0
Number of packets added to the queue to send later.

status : packet-in-TYPE-dropped: optional string, containing an integer, at least 0
Number of packets added to the queue that were later dropped due to overflow. This
value is less than or equal to status:packet-in-TYPE-queued.

status : packet-in-TYPE-backlog: optional string, containing an integer, at least 0
Number of packets currently queued. The other statistics increase monotonically,
but this one fluctuates between 0 and the controller_burst_limit as conditions
change.

Additional In-Band Configuration:

These values are considered only in in-band control mode (see connection_mode).

When multiple controllers are configured on a single bridge, there should be only one set
of unique values in these columns. If different values are set for these columns in
different controllers, the effect is unspecified.

local_ip: optional string
The IP address to configure on the local port, e.g. 192.168.0.123. If this value is
unset, then local_netmask and local_gateway are ignored.

local_netmask: optional string
The IP netmask to configure on the local port, e.g. 255.255.255.0. If local_ip is
set but this value is unset, then the default is chosen based on whether the IP
address is class A, B, or C.

local_gateway: optional string
The IP address of the gateway to configure on the local port, as a string, e.g.
192.168.0.1. Leave this column unset if this network has no gateway.

Controller Status:

is_connected: boolean
true if currently connected to this controller, false otherwise.

role: optional string, one of master, other, or slave
The level of authority this controller has on the associated bridge. Possible
values are:

other Allows the controller access to all OpenFlow features.

master Equivalent to other, except that there may be at most one such controller at
a time. If a given controller promotes itself to this role, ovs-vswitchd
demotes any existing controller with the role to slave.

slave Allows the controller read-only access to OpenFlow features. Attempts to
modify the flow table will be rejected with an error. Such controllers do
not receive OFPT_PACKET_IN or OFPT_FLOW_REMOVED messages, but they do
receive OFPT_PORT_STATUS messages.

status : last_error: optional string
A human-readable description of the last error on the connection to the controller;
i.e. strerror(errno). This key will exist only if an error has occurred.

status : state: optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE, or VOID
The state of the connection to the controller:

VOID Connection is disabled.

BACKOFF
Attempting to reconnect at an increasing period.

CONNECTING
Attempting to connect.

ACTIVE Connected, remote host responsive.

IDLE Connection is idle. Waiting for response to keep-alive.

These values may change in the future. They are provided only for human
consumption.

status : sec_since_connect: optional string, containing an integer, at least 0
The amount of time since this controller last successfully connected to the switch
(in seconds). Value is empty if controller has never successfully connected.

status : sec_since_disconnect: optional string, containing an integer, at least 1
The amount of time since this controller last disconnected from the switch (in
seconds). Value is empty if controller has never disconnected.

Connection Parameters:

Additional configuration for a connection between the controller and the Open vSwitch.

other_config : dscp: optional string, containing an integer
The Differentiated Service Code Point (DSCP) is specified using 6 bits in the Type
of Service (TOS) field in the IP header. DSCP provides a mechanism to classify the
network traffic and provide Quality of Service (QoS) on IP networks. The DSCP value
specified here is used when establishing the connection between the controller and
the Open vSwitch. If no value is specified, a default value of 48 is chosen. Valid
DSCP values must be in the range 0 to 63.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

other_config: map of string-string pairs

Manager TABLE

Configuration for a database connection to an Open vSwitch database (OVSDB) client.

This table primarily configures the Open vSwitch database (ovsdb-server), not the Open
vSwitch switch (ovs-vswitchd). The switch does read the table to determine what
connections should be treated as in-band.

The Open vSwitch database server can initiate and maintain active connections to remote
clients. It can also listen for database connections.

Summary:
Core Features:
target string (must be unique within table)
connection_mode optional string, either in-band or out-of-band
Client Failure Detection and Handling:
max_backoff optional integer, at least 1,000
inactivity_probe optional integer
Status:
is_connected boolean
status : last_error optional string
status : state optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE,
or VOID
status : sec_since_connect optional string, containing an integer, at least 0
status : sec_since_disconnect
optional string, containing an integer, at least 0
status : locks_held optional string
status : locks_waiting optional string
status : locks_lost optional string
status : n_connections optional string, containing an integer, at least 2
status : bound_port optional string, containing an integer
Connection Parameters:
other_config : dscp optional string, containing an integer
Common Columns:
external_ids map of string-string pairs
other_config map of string-string pairs

Details:
Core Features:

target: string (must be unique within table)
Connection method for managers.

The following connection methods are currently supported:

If port is not specified, it defaults to 6640.

SSL support is an optional feature that is not always built as part of Open
vSwitch.

If port is not specified, it defaults to 6640.

pssl:[port][:host]
Listens for SSL connections on the specified TCP port. Specify 0 for port to
have the kernel automatically choose an available port. If host, which can
either be a DNS name (if built with unbound library) or an IP address, is
specified, then connections are restricted to the resolved or specified
local IP address (either IPv4 or IPv6 address). If host is an IPv6 address,
wrap in square brackets, e.g. pssl:6640:[::1]. If host is not specified then
it listens only on IPv4 (but not IPv6) addresses. The ssl column in the
Open_vSwitch table must point to a valid SSL configuration when this form is
used.

If port is not specified, it defaults to 6640.

SSL support is an optional feature that is not always built as part of Open
vSwitch.

ptcp:[port][:host]
Listens for connections on the specified TCP port. Specify 0 for port to
have the kernel automatically choose an available port. If host, which can
either be a DNS name (if built with unbound library) or an IP address, is
specified, then connections are restricted to the resolved or specified
local IP address (either IPv4 or IPv6 address). If host is an IPv6 address,
wrap it in square brackets, e.g. ptcp:6640:[::1]. If host is not specified
then it listens only on IPv4 addresses.

If port is not specified, it defaults to 6640.

When multiple managers are configured, the target values must be unique. Duplicate
target values yield unspecified results.

in-band
In this mode, this connection’s traffic travels over a bridge managed by
Open vSwitch. With this setting, Open vSwitch allows traffic to and from the
client regardless of the contents of the OpenFlow flow table. (Otherwise,
Open vSwitch would never be able to connect to the client, because it did
not have a flow to enable it.) This is the most common connection mode
because it is not necessary to maintain two independent networks.

out-of-band
In this mode, the client’s traffic uses a control network separate from that
managed by Open vSwitch, that is, Open vSwitch does not use any of its own
network devices to communicate with the client. The control network must be
configured separately, before or after ovs-vswitchd is started.

If not specified, the default is implementation-specific.

Client Failure Detection and Handling:

max_backoff: optional integer, at least 1,000
Maximum number of milliseconds to wait between connection attempts. Default is
implementation-specific.

inactivity_probe: optional integer
Maximum number of milliseconds of idle time on connection to the client before
sending an inactivity probe message. If Open vSwitch does not communicate with the
client for the specified number of seconds, it will send a probe. If a response is
not received for the same additional amount of time, Open vSwitch assumes the
connection has been broken and attempts to reconnect. Default is implementation-
specific. A value of 0 disables inactivity probes.

Status:

Key-value pair of is_connected is always updated. Other key-value pairs in the status
columns may be updated depends on the target type.

When target specifies a connection method that listens for inbound connections (e.g. ptcp:
or punix:), both n_connections and is_connected may also be updated while the remaining
key-value pairs are omitted.

On the other hand, when target specifies an outbound connection, all key-value pairs may
be updated, except the above-mentioned two key-value pairs associated with inbound
connection targets. They are omitted.

is_connected: boolean
true if currently connected to this manager, false otherwise.

status : last_error: optional string
A human-readable description of the last error on the connection to the manager;
i.e. strerror(errno). This key will exist only if an error has occurred.

status : state: optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE, or VOID
The state of the connection to the manager:

VOID Connection is disabled.

BACKOFF
Attempting to reconnect at an increasing period.

CONNECTING
Attempting to connect.

ACTIVE Connected, remote host responsive.

IDLE Connection is idle. Waiting for response to keep-alive.

These values may change in the future. They are provided only for human
consumption.

status : sec_since_connect: optional string, containing an integer, at least 0
The amount of time since this manager last successfully connected to the database
(in seconds). Value is empty if manager has never successfully connected.

status : sec_since_disconnect: optional string, containing an integer, at least 0
The amount of time since this manager last disconnected from the database (in
seconds). Value is empty if manager has never disconnected.

status : locks_held: optional string
Space-separated list of the names of OVSDB locks that the connection holds. Omitted
if the connection does not hold any locks.

status : locks_waiting: optional string
Space-separated list of the names of OVSDB locks that the connection is currently
waiting to acquire. Omitted if the connection is not waiting for any locks.

status : locks_lost: optional string
Space-separated list of the names of OVSDB locks that the connection has had stolen
by another OVSDB client. Omitted if no locks have been stolen from this connection.

status : n_connections: optional string, containing an integer, at least 2
When target specifies a connection method that listens for inbound connections
(e.g. ptcp: or pssl:) and more than one connection is actually active, the value is
the number of active connections. Otherwise, this key-value pair is omitted.

status : bound_port: optional string, containing an integer
When target is ptcp: or pssl:, this is the TCP port on which the OVSDB server is
listening. (This is particularly useful when target specifies a port of 0, allowing
the kernel to choose any available port.)

Connection Parameters:

Additional configuration for a connection between the manager and the Open vSwitch
Database.

other_config : dscp: optional string, containing an integer
The Differentiated Service Code Point (DSCP) is specified using 6 bits in the Type
of Service (TOS) field in the IP header. DSCP provides a mechanism to classify the
network traffic and provide Quality of Service (QoS) on IP networks. The DSCP value
specified here is used when establishing the connection between the manager and the
Open vSwitch. If no value is specified, a default value of 48 is chosen. Valid DSCP
values must be in the range 0 to 63.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

other_config: map of string-string pairs

NetFlow TABLE

A NetFlow target. NetFlow is a protocol that exports a number of details about terminating
IP flows, such as the principals involved and duration.

Summary:
targets set of 1 or more strings
engine_id optional integer, in range 0 to 255
engine_type optional integer, in range 0 to 255
active_timeout integer, at least -1
add_id_to_interface boolean
Common Columns:
external_ids map of string-string pairs

Details:
targets: set of 1 or more strings
NetFlow targets in the form ip:port. The ip must be specified numerically, not as a
DNS name.

engine_id: optional integer, in range 0 to 255
Engine ID to use in NetFlow messages. Defaults to datapath index if not specified.

engine_type: optional integer, in range 0 to 255
Engine type to use in NetFlow messages. Defaults to datapath index if not
specified.

active_timeout: integer, at least -1
The interval at which NetFlow records are sent for flows that are still active, in
seconds. A value of 0 requests the default timeout (currently 600 seconds); a value
of -1 disables active timeouts.

The NetFlow passive timeout, for flows that become inactive, is not configurable.
It will vary depending on the Open vSwitch version, the forms and contents of the
OpenFlow flow tables, CPU and memory usage, and network activity. A typical passive
timeout is about a second.

add_id_to_interface: boolean
If this column’s value is false, the ingress and egress interface fields of NetFlow
flow records are derived from OpenFlow port numbers. When it is true, the 7 most
significant bits of these fields will be replaced by the least significant 7 bits
of the engine id. This is useful because many NetFlow collectors do not expect
multiple switches to be sending messages from the same host, so they do not store
the engine information which could be used to disambiguate the traffic.

When this option is enabled, a maximum of 508 ports are supported.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

Datapath TABLE

Configuration for a datapath within Open_vSwitch.

A datapath is responsible for providing the packet handling in Open vSwitch. There are two
primary datapath implementations used by Open vSwitch: kernel and userspace. Kernel
datapath implementations are available for Linux and Hyper-V, and selected as system in
the datapath_type column of the Bridge table. The userspace datapath is used by DPDK and
AF-XDP, and is selected as netdev in the datapath_type column of the Bridge table.

A datapath of a particular type is shared by all the bridges that use that datapath. Thus,
configurations applied to this table affect all bridges that use this datapath.

Summary:
datapath_version string
ct_zones map of integer-CT_Zone pairs, key in range 0 to 65,535
Capabilities:
capabilities : max_vlan_headers
optional string, containing an integer, at least 0
capabilities : recirc optional string, either true or false
capabilities : lb_output_action
optional string, either true or false
Connection-Tracking Capabilities:
capabilities : ct_state optional string, either true or false
capabilities : ct_state_nat
optional string, either true or false
capabilities : ct_zone optional string, either true or false
capabilities : ct_mark optional string, either true or false
capabilities : ct_label optional string, either true or false
capabilities : ct_orig_tuple
optional string, either true or false
capabilities : ct_orig_tuple6
optional string, either true or false
capabilities : masked_set_action
optional string, either true or false
capabilities : tnl_push_pop
optional string, either true or false
capabilities : ufid optional string, either true or false
capabilities : trunc optional string, either true or false
capabilities : nd_ext optional string, either true or false
Clone Actions:
capabilities : clone optional string, either true or false
capabilities : sample_nesting
optional string, containing an integer, at least 0
capabilities : ct_eventmask
optional string, either true or false
capabilities : ct_clear optional string, either true or false
capabilities : max_hash_alg
optional string, containing an integer, at least 0
capabilities : check_pkt_len
optional string, either true or false
capabilities : ct_timeout optional string, either true or false
capabilities : explicit_drop_action
optional string, either true or false
capabilities : ct_zero_snat
optional string, either true or false
capabilities : ct_flush optional string, either true or false
Common Columns:
external_ids map of string-string pairs

Details:
datapath_version: string
Reports the version number of the Open vSwitch datapath in use. This allows
management software to detect and report discrepancies between Open vSwitch
userspace and datapath versions. (The ovs_version column in the Open_vSwitch
reports the Open vSwitch userspace version.) The version reported depends on the
datapath in use:

• When the kernel module included in the Open vSwitch source tree is used,
this column reports the Open vSwitch version from which the module was
taken.

• When the kernel module that is part of the upstream Linux kernel is used,
this column reports <unknown>.

• When the datapath is built into the ovs-vswitchd binary, this column reports
<built-in>. A built-in datapath is by definition the same version as the
rest of the Open vSwitch userspace.

• Other datapaths (such as the Hyper-V kernel datapath) currently report
<unknown>.

A version discrepancy between ovs-vswitchd and the datapath in use is not normally
cause for alarm. The Open vSwitch kernel datapaths for Linux and Hyper-V, in
particular, are designed for maximum inter-version compatibility: any userspace
version works with with any kernel version. Some reasons do exist to insist on
particular user/kernel pairings. First, newer kernel versions add new features,
that can only be used by new-enough userspace, e.g. VXLAN tunneling requires
certain minimal userspace and kernel versions. Second, as an extension to the first
reason, some newer kernel versions add new features for enhancing performance that
only new-enough userspace versions can take advantage of.

ct_zones: map of integer-CT_Zone pairs, key in range 0 to 65,535
Configuration for connection tracking zones. Each pair maps from a zone id to a
configuration for that zone. Zone 0 applies to the default zone (ie, the one used
if a zone is not specified in connection tracking-related OpenFlow matches and
actions).

Capabilities:

The capabilities column reports a datapath’s features. For the netdev datapath, the
capabilities are fixed for a given version of Open vSwitch because this datapath is built
into the ovs-vswitchd binary. The Linux kernel and Windows and other datapaths, which are
external to OVS userspace, can vary in version and capabilities independently from
ovs-vswitchd.

Some of these features indicate whether higher-level Open vSwitch features are available.
For example, OpenFlow features for connection-tracking are available only when
capabilities:ct_state is true. A controller that wishes to determine whether a feature is
supported could, therefore, consult the relevant capabilities in this table. However, as a
general rule, it is better for a controller to try to use the higher-level feature and use
the result as an indication of support, since the low-level capabilities are more likely
to shift over time than the high-level features that rely on them.

capabilities : max_vlan_headers: optional string, containing an integer, at least 0
Number of 802.1q VLAN headers supported by the datapath, as probed by the
ovs-vswitchd slow path. If the datapath supports more VLAN headers than the slow
path, this reports the slow path’s limit. The value of other-config:vlan-limit in
the Open_vSwitch table does not influence the number reported here.

capabilities : recirc: optional string, either true or false
If this is true, then the datapath supports recirculation, specifically
OVS_KEY_ATTR_RECIRC_ID. Recirculation enables higher performance for MPLS and
active-active load balancing bonding modes.

capabilities : lb_output_action: optional string, either true or false
If this is true, then the datapath supports optimized balance-tcp bond mode. This
capability replaces existing hash and recirc actions with new action lb_output and
avoids recirculation of packet in datapath. It is supported only for balance-tcp
bond mode in netdev datapath. The new action gives higher performance by using bond
buckets instead of post recirculation flows for selection of slave port from bond.
By default this new action is disabled, however it can be enabled by setting other-
config:lb-output-action in Port table.

Connection-Tracking Capabilities:

These capabilities are granular because Open vSwitch and its datapaths added support for
connection tracking over several releases, with features added individually over that
time.

capabilities : ct_state: optional string, either true or false
If true, datapath supports OVS_KEY_ATTR_CT_STATE, which indicates support for the
bits in the OpenFlow ct_state field (see ovs-fields(7)) other than snat and dnat,
which have a separate capability.

If this is false, the datapath does not support connection-tracking at all and the
remaining connection-tracking capabilities should all be false. In this case, Open
vSwitch will reject flows that match on the ct_state field or use the ct action.

capabilities : ct_state_nat: optional string, either true or false
If true, it means that the datapath supports the snat and dnat flags in the
OpenFlow ct_state field. The ct_state capability must be true for this to make
sense.

If false, Open vSwitch will reject flows that match on the snat or dnat bits in
ct_state or use nat in the ct action.

capabilities : ct_zone: optional string, either true or false
If true, datapath supports OVS_KEY_ATTR_CT_ZONE. If false, Open vSwitch rejects
flows that match on the ct_zone field or that specify a nonzero zone or a zone
field on the ct action.

capabilities : ct_mark: optional string, either true or false
If true, datapath supports OVS_KEY_ATTR_CT_MARK. If false, Open vSwitch rejects
flows that match on the ct_mark field or that set ct_mark in the ct action.

capabilities : ct_label: optional string, either true or false
If true, datapath supports OVS_KEY_ATTR_CT_LABEL. If false, Open vSwitch rejects
flows that match on the ct_label field or that set ct_label in the ct action.

capabilities : ct_orig_tuple: optional string, either true or false
If true, the datapath supports matching the 5-tuple from the connection’s original
direction for IPv4 traffic. If false, Open vSwitch rejects flows that match on
ct_nw_src or ct_nw_dst, that use the ct feature of the resubmit action, or the
force keyword in the ct action. (The latter isn’t tied to connection tracking
support of original tuples in any technical way. They are conflated because all
current datapaths implemented the two features at the same time.)

If this and capabilities:ct_orig_tuple6 are both false, Open vSwitch rejects flows
that match on ct_nw_proto, ct_tp_src, or ct_tp_dst.

capabilities : ct_orig_tuple6: optional string, either true or false
If true, the datapath supports matching the 5-tuple from the connection’s original
direction for IPv6 traffic. If false, Open vSwitch rejects flows that match on
ct_ipv6_src or ct_ipv6_dst.

capabilities : masked_set_action: optional string, either true or false
True if the datapath supports masked data in OVS_ACTION_ATTR_SET actions. Masked
data can improve performance by allowing megaflows to match on fewer fields.

capabilities : tnl_push_pop: optional string, either true or false
True if the datapath supports tnl_push and pop actions. This is a prerequisite for
a datapath to support native tunneling.

capabilities : ufid: optional string, either true or false
True if the datapath supports OVS_FLOW_ATTR_UFID. UFID support improves
revalidation performance by transferring less data between the slow path and the
datapath.

capabilities : trunc: optional string, either true or false
True if the datapath supports OVS_ACTION_ATTR_TRUNC action. If false, the output
action with packet truncation requires every packet to be sent to the Open vSwitch
slow path, which is likely to make it too slow for mirroring traffic in bulk.

capabilities : nd_ext: optional string, either true or false
True if the datapath supports OVS_KEY_ATTR_ND_EXTENSIONS to match on ICMPv6 "ND
reserved" and "ND option type" header fields. If false, the datapath reports error
if the feature is used.

Clone Actions:

When Open vSwitch translates actions from OpenFlow into the datapath representation, some
of the datapath actions may modify the packet or have other side effects that later
datapath actions can’t undo. The OpenFlow ct, meter, output with truncation, encap, decap,
and dec_nsh_ttl actions fall into this category. Often, this is not a problem because
nothing later on needs the original packet.

Such actions can, however, occur in circumstances where the translation does require the
original packet. For example, an OpenFlow output action might direct a packet to a patch
port, which might in turn lead to a ct action that NATs the packet (which cannot be
undone), and then afterward when control flow pops back across the patch port some other
action might need to act on the original packet.

Open vSwitch has two different ways to implement this ``save and restore’’ via datapath
actions. These capabilities indicate which one Open vSwitch will choose. When neither is
available, Open vSwitch simply fails in situations that require this feature.

capabilities : clone: optional string, either true or false
True if the datapath supports OVS_ACTION_ATTR_CLONE action. This is the preferred
option for saving and restoring packets, since it is intended for the purpose, but
old datapaths do not support it. Open vSwitch will use it whenever it is available.

(The OpenFlow clone action does not always yield a OVS_ACTION_ATTR_CLONE action. It
only does so when the datapath supports it and the clone brackets actions that
otherwise cannot be undone.)

capabilities : sample_nesting: optional string, containing an integer, at least 0
Maximum level of nesting allowed by OVS_ACTION_ATTR_SAMPLE action. Open vSwitch
misuses this action for saving and restoring packets when the datapath supports
more than 3 levels of nesting and OVS_ACTION_ATTR_CLONE is not available.

capabilities : ct_eventmask: optional string, either true or false
True if the datapath’s OVS_ACTION_ATTR_CT action implements the
OVS_CT_ATTR_EVENTMASK attribute. When this is true, Open vSwitch uses the event
mask feature to limit the kinds of events reported to conntrack update listeners.
When Open vSwitch doesn’t limit the event mask, listeners receive reports of
numerous usually unimportant events, such as TCP state machine changes, which can
waste CPU time.

capabilities : ct_clear: optional string, either true or false
True if the datapath supports OVS_ACTION_ATTR_CT_CLEAR action. If false, the
OpenFlow ct_clear action has no effect on the datapath.

capabilities : max_hash_alg: optional string, containing an integer, at least 0
Highest supported dp_hash algorithm. This allows Open vSwitch to avoid requesting a
packet hash that the datapath does not support.

capabilities : check_pkt_len: optional string, either true or false
True if the datapath supports OVS_ACTION_ATTR_CHECK_PKT_LEN. If false, Open vSwitch
implements the check_pkt_larger action by sending every packet through the Open
vSwitch slow path, which is likely to make it too slow for handling traffic in
bulk.

capabilities : ct_timeout: optional string, either true or false
True if the datapath supports OVS_CT_ATTR_TIMEOUT in the OVS_ACTION_ATTR_CT action.
If false, Open vswitch cannot implement timeout policies based on connection
tracking zones, as configured through the CT_Timeout_Policy table.

capabilities : explicit_drop_action: optional string, either true or false
True if the datapath supports OVS_ACTION_ATTR_DROP. If false, explicit drop action
will not be sent to the datapath.

capabilities : ct_zero_snat: optional string, either true or false
True if the datapath supports all-zero SNAT. This is a special case if the src IP
address is configured as all 0’s, i.e., nat(src=0.0.0.0). In this case, when a
source port collision is detected during the commit, the source port will be
translated to an ephemeral port. If there is no collision, no SNAT is performed.

capabilities : ct_flush: optional string, either true or false
True if the datapath supports CT flush OpenFlow Nicira extension called
NXT_CT_FLUSH. The NXT_CT_FLUSH extensions allows to flush CT entries based on
specified parameters.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

CT_Zone TABLE

       Connection tracking zone configuration

   Summary:
       timeout_policy                optional CT_Timeout_Policy
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       timeout_policy: optional CT_Timeout_Policy
              Connection tracking timeout policy for this  zone.  If  a  timeout  policy  is  not
              specified, it defaults to the timeout policy in the system.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

CT_Timeout_Policy TABLE

       Connection tracking timeout policy configuration

   Summary:
       Timeouts:
         timeouts                    map  of  string-integer  pairs,  key  one   of   icmp_first,
                                     icmp_reply,   tcp_close,   tcp_close_wait,  tcp_established,
                                     tcp_fin_wait,  tcp_last_ack,  tcp_retransmit,  tcp_syn_recv,
                                     tcp_syn_sent2,   tcp_syn_sent,   tcp_time_wait,   tcp_unack,
                                     udp_first, udp_multiple, or udp_single, value in range 0  to
                                     4,294,967,295
         TCP Timeouts:
            timeouts : tcp_syn_sent  optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_syn_recv  optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_established
                                     optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_fin_wait  optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_close_wait
                                     optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_last_ack  optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_time_wait optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_close     optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_syn_sent2 optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_retransmit
                                     optional integer, in range 0 to 4,294,967,295
            timeouts : tcp_unack     optional integer, in range 0 to 4,294,967,295
         UDP Timeouts:
            timeouts : udp_first     optional integer, in range 0 to 4,294,967,295
            timeouts : udp_single    optional integer, in range 0 to 4,294,967,295
            timeouts : udp_multiple  optional integer, in range 0 to 4,294,967,295
         ICMP Timeouts:
            timeouts : icmp_first    optional integer, in range 0 to 4,294,967,295
            timeouts : icmp_reply    optional integer, in range 0 to 4,294,967,295
       Common Columns:
         external_ids                map of string-string pairs

   Details:
     Timeouts:

       timeouts:  map  of  string-integer  pairs,  key  one of icmp_first, icmp_reply, tcp_close,
       tcp_close_wait, tcp_established, tcp_fin_wait, tcp_last_ack, tcp_retransmit, tcp_syn_recv,
       tcp_syn_sent2,   tcp_syn_sent,   tcp_time_wait,  tcp_unack,  udp_first,  udp_multiple,  or
       udp_single, value in range 0 to 4,294,967,295
              The timeouts column contains key-value pairs used to configure connection  tracking
              timeouts  in  a  datapath. Key-value pairs that are not supported by a datapath are
              ignored. The timeout value is in seconds.

     TCP Timeouts:

       timeouts : tcp_syn_sent: optional integer, in range 0 to 4,294,967,295
              The timeout for the connection after the first TCP SYN  packet  has  been  seen  by
              conntrack.

       timeouts : tcp_syn_recv: optional integer, in range 0 to 4,294,967,295
              The  timeout  of the connection after the first TCP SYN-ACK packet has been seen by
              conntrack.

       timeouts : tcp_established: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection after the connection has been fully established.

       timeouts : tcp_fin_wait: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection after the first TCP  FIN  packet  has  been  seen  by
              conntrack.

       timeouts : tcp_close_wait: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection after the first TCP ACK packet has been seen after it
              receives TCP FIN packet. This  timeout  is  only  supported  by  the  Linux  kernel
              datapath.

       timeouts : tcp_last_ack: optional integer, in range 0 to 4,294,967,295
              The  timeout  of  the  connection after TCP FIN packets have been seen by conntrack
              from both directions. This timeout is only supported by the Linux kernel datapath.

       timeouts : tcp_time_wait: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection after conntrack has seen the TCP ACK packet  for  the
              second TCP FIN packet.

       timeouts : tcp_close: optional integer, in range 0 to 4,294,967,295
              The  timeout  of  the  connection  after  the first TCP RST packet has been seen by
              conntrack.

       timeouts : tcp_syn_sent2: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection when only a TCP SYN packet has been seen by conntrack
              from  both  directions  (simultaneous  open). This timeout is only supported by the
              Linux kernel datapath.

       timeouts : tcp_retransmit: optional integer, in range 0 to 4,294,967,295
              The  timeout  of  the  connection  when  it   exceeds   the   maximum   number   of
              retransmissions. This timeout is only supported by the Linux kernel datapath.

       timeouts : tcp_unack: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection when non-SYN packets create an established connection
              in TCP loose tracking mode. This timeout is only  supported  by  the  Linux  kernel
              datapath.

     UDP Timeouts:

       timeouts : udp_first: optional integer, in range 0 to 4,294,967,295
              The  timeout  of  the  connection  after  the  first  UDP  packet  has been seen by
              conntrack. This timeout is only supported by the userspace datapath.

       timeouts : udp_single: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection when conntrack only seen UDP packet from  the  source
              host, but the destination host has never sent one back.

       timeouts : udp_multiple: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection when UDP packets have been seen in both directions.

     ICMP Timeouts:

       timeouts : icmp_first: optional integer, in range 0 to 4,294,967,295
              The  timeout  of  the  connection  after  the  first  ICMP  packet has been seen by
              conntrack.

       timeouts : icmp_reply: optional integer, in range 0 to 4,294,967,295
              The timeout of the connection when ICMP packets have been seen in  both  direction.
              This timeout is only supported by the userspace datapath.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

SSL TABLE

       SSL configuration for an Open_vSwitch.

   Summary:
       private_key                   string
       certificate                   string
       ca_cert                       string
       bootstrap_ca_cert             boolean
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       private_key: string
              Name of a PEM file containing the private key used as the switch’s identity for SSL
              connections to the controller.

       certificate: string
              Name  of  a  PEM file containing a certificate, signed by the certificate authority
              (CA) used by the controller and manager, that certifies the switch’s  private  key,
              identifying a trustworthy switch.

       ca_cert: string
              Name  of a PEM file containing the CA certificate used to verify that the switch is
              connected to a trustworthy controller.

       bootstrap_ca_cert: boolean
              If set to true, then Open vSwitch will attempt to obtain the  CA  certificate  from
              the controller on its first SSL connection and save it to the named PEM file. If it
              is successful, it will immediately drop the connection and reconnect, and from then
              on  all  SSL  connections  must  be authenticated by a certificate signed by the CA
              certificate  thus  obtained.  This  option  exposes  the  SSL   connection   to   a
              man-in-the-middle  attack  obtaining  the  initial  CA certificate. It may still be
              useful for bootstrapping.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

sFlow TABLE

A set of sFlow(R) targets. sFlow is a protocol for remote monitoring of switches.

Summary:
agent optional string
header optional integer
polling optional integer
sampling optional integer
targets set of 1 or more strings
Common Columns:
external_ids map of string-string pairs

Details:
agent: optional string
Determines the agent address, that is, the IP address reported to collectors as the
source of the sFlow data. It may be an IP address or the name of a network device.
In the latter case, the network device’s IP address is used,

If not specified, the agent device is figured from the first target address and the
routing table. If the routing table does not contain a route to the target, the IP
address defaults to the local_ip in the collector’s Controller.

If an agent IP address cannot be determined, sFlow is disabled.

header: optional integer
Number of bytes of a sampled packet to send to the collector. If not specified, the
default is 128 bytes.

polling: optional integer
Polling rate in seconds to send port statistics to the collector. If not specified,
defaults to 30 seconds.

sampling: optional integer
Rate at which packets should be sampled and sent to the collector. If not
specified, defaults to 400, which means one out of 400 packets, on average, will be
sent to the collector.

targets: set of 1 or more strings
sFlow targets in the form ip:port.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

IPFIX TABLE

Configuration for sending packets to IPFIX collectors.

IPFIX is a protocol that exports a number of details about flows. The IPFIX implementation
in Open vSwitch samples packets at a configurable rate, extracts flow information from
those packets, optionally caches and aggregates the flow information, and sends the result
to one or more collectors.

IPFIX in Open vSwitch can be configured two different ways:

• With per-bridge sampling, Open vSwitch performs IPFIX sampling automatically
on all packets that pass through a bridge. To configure per-bridge sampling,
create an IPFIX record and point a Bridge table’s ipfix column to it. The
Flow_Sample_Collector_Set table is not used for per-bridge sampling.

• With flow-based sampling, sample actions in the OpenFlow flow table drive
IPFIX sampling. See ovs-actions(7) for a description of the sample action.

Flow-based sampling also requires database configuration: create a IPFIX
record that describes the IPFIX configuration and a
Flow_Sample_Collector_Set record that points to the Bridge whose flow table
holds the sample actions and to IPFIX record. The ipfix in the Bridge table
is not used for flow-based sampling.

Summary:
targets set of strings
cache_active_timeout optional integer, in range 0 to 4,200
cache_max_flows optional integer, in range 0 to 4,294,967,295
stats_interval optional integer, in range 1 to 3,600
template_interval optional integer, in range 1 to 3,600
other_config : enable-tunnel-sampling
optional string, either true or false
other_config : virtual_obs_id optional string
Per-Bridge Sampling:
sampling optional integer, in range 1 to 4,294,967,295
obs_domain_id optional integer, in range 0 to 4,294,967,295
obs_point_id optional integer, in range 0 to 4,294,967,295
other_config : enable-input-sampling
optional string, either true or false
other_config : enable-output-sampling
optional string, either true or false
Common Columns:
external_ids map of string-string pairs

Details:
targets: set of strings
IPFIX target collectors in the form ip:port.

cache_active_timeout: optional integer, in range 0 to 4,200
The maximum period in seconds for which an IPFIX flow record is cached and
aggregated before being sent. If not specified, defaults to 0. If 0, caching is
disabled.

cache_max_flows: optional integer, in range 0 to 4,294,967,295
The maximum number of IPFIX flow records that can be cached at a time. If not
specified, defaults to 0. If 0, caching is disabled.

stats_interval: optional integer, in range 1 to 3,600
Interval (in seconds) for sending IPFIX exporting process statistics according to
IETF RFC 5101 Section 4.3.

Default value is 600

template_interval: optional integer, in range 1 to 3,600
Interval (in seconds) for sending IPFIX Template information for each Observation
Domain ID.

Default value is 600

other_config : enable-tunnel-sampling: optional string, either true or false
Set to true to enable sampling and reporting tunnel header 7-tuples in IPFIX flow
records. Tunnel sampling is enabled by default.

The following enterprise entities report the sampled tunnel info:

tunnelType:
ID: 891, and enterprise ID 6876 (VMware).

type: unsigned 8-bit integer.

data type semantics: identifier.

description: Identifier of the layer 2 network overlay network encapsulation
type: 0x01 VxLAN, 0x02 GRE, 0x03 LISP, 0x07 GENEVE.

tunnelKey:
ID: 892, and enterprise ID 6876 (VMware).

type: variable-length octetarray.

data type semantics: identifier.

description: Key which is used for identifying an individual traffic flow
within a VxLAN (24-bit VNI), GENEVE (24-bit VNI), GRE (32-bit key), or LISP
(24-bit instance ID) tunnel. The key is encoded in this octetarray as a 3-,
4-, or 8-byte integer ID in network byte order.

tunnelSourceIPv4Address:
ID: 893, and enterprise ID 6876 (VMware).

type: unsigned 32-bit integer.

data type semantics: identifier.

description: The IPv4 source address in the tunnel IP packet header.

tunnelDestinationIPv4Address:
ID: 894, and enterprise ID 6876 (VMware).

type: unsigned 32-bit integer.

data type semantics: identifier.

description: The IPv4 destination address in the tunnel IP packet header.

tunnelProtocolIdentifier:
ID: 895, and enterprise ID 6876 (VMware).

type: unsigned 8-bit integer.

data type semantics: identifier.

description: The value of the protocol number in the tunnel IP packet
header. The protocol number identifies the tunnel IP packet payload type.

tunnelSourceTransportPort:
ID: 896, and enterprise ID 6876 (VMware).

type: unsigned 16-bit integer.

data type semantics: identifier.

description: The source port identifier in the tunnel transport header. For
the transport protocols UDP, TCP, and SCTP, this is the source port number
given in the respective header.

tunnelDestinationTransportPort:
ID: 897, and enterprise ID 6876 (VMware).

type: unsigned 16-bit integer.

data type semantics: identifier.

description: The destination port identifier in the tunnel transport header.
For the transport protocols UDP, TCP, and SCTP, this is the destination port
number given in the respective header.

Before Open vSwitch 2.5.90, other_config:enable-tunnel-sampling was only supported
with per-bridge sampling, and ignored otherwise. Open vSwitch 2.5.90 and later
support other_config:enable-tunnel-sampling for per-bridge and per-flow sampling.

other_config : virtual_obs_id: optional string
A string that accompanies each IPFIX flow record. Its intended use is for the
``virtual observation ID,’’ an identifier of a virtual observation point that is
locally unique in a virtual network. It describes a location in the virtual network
where IP packets can be observed. The maximum length is 254 bytes. If not
specified, the field is omitted from the IPFIX flow record.

The following enterprise entity reports the specified virtual observation ID:

virtualObsID:
ID: 898, and enterprise ID 6876 (VMware).

type: variable-length string.

data type semantics: identifier.

description: A virtual observation domain ID that is locally unique in a
virtual network.

This feature was introduced in Open vSwitch 2.5.90.

Per-Bridge Sampling:

These values affect only per-bridge sampling. See above for a description of the
differences between per-bridge and flow-based sampling.

sampling: optional integer, in range 1 to 4,294,967,295
The rate at which packets should be sampled and sent to each target collector. If
not specified, defaults to 400, which means one out of 400 packets, on average,
will be sent to each target collector.

obs_domain_id: optional integer, in range 0 to 4,294,967,295
The IPFIX Observation Domain ID sent in each IPFIX packet. If not specified,
defaults to 0.

obs_point_id: optional integer, in range 0 to 4,294,967,295
The IPFIX Observation Point ID sent in each IPFIX flow record. If not specified,
defaults to 0.

other_config : enable-input-sampling: optional string, either true or false
By default, Open vSwitch samples and reports flows at bridge port input in IPFIX
flow records. Set this column to false to disable input sampling.

other_config : enable-output-sampling: optional string, either true or false
By default, Open vSwitch samples and reports flows at bridge port output in IPFIX
flow records. Set this column to false to disable output sampling.

Common Columns:

The overall purpose of these columns is described under Common Columns at the beginning of
this document.

external_ids: map of string-string pairs

Flow_Sample_Collector_Set TABLE

       A  set  of  IPFIX  collectors of packet samples generated by OpenFlow sample actions. This
       table is used only for IPFIX flow-based sampling, not for  per-bridge  sampling  (see  the
       IPFIX table for a description of the two forms).

   Summary:
       id                            integer, in range 0 to 4,294,967,295
       bridge                        Bridge
       ipfix                         optional IPFIX
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       id: integer, in range 0 to 4,294,967,295
              The  ID of this collector set, unique among the bridge’s collector sets, to be used
              as the collector_set_id in OpenFlow sample actions.

       bridge: Bridge
              The bridge into which OpenFlow sample actions can be added to send  packet  samples
              to this set of IPFIX collectors.

       ipfix: optional IPFIX
              Configuration  of  the  set of IPFIX collectors to send one flow record per sampled
              packet to.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

AutoAttach TABLE

Auto Attach configuration within a bridge. The IETF Auto-Attach SPBM draft standard
describes a compact method of using IEEE 802.1AB Link Layer Discovery Protocol (LLDP)
together with a IEEE 802.1aq Shortest Path Bridging (SPB) network to automatically attach
network devices to individual services in a SPB network. The intent here is to allow
network applications and devices using OVS to be able to easily take advantage of features
offered by industry standard SPB networks.

Auto Attach (AA) uses LLDP to communicate between a directly connected Auto Attach Client
(AAC) and Auto Attach Server (AAS). The LLDP protocol is extended to add two new Type-
Length-Value tuples (TLVs). The first new TLV supports the ongoing discovery of directly
connected AA correspondents. Auto Attach operates by regularly transmitting AA discovery
TLVs between the AA client and AA server. By exchanging these discovery messages, both the
AAC and AAS learn the system name and system description of their peer. In the OVS
context, OVS operates as the AA client and the AA server resides on a switch at the edge
of the SPB network.

Once AA discovery has been completed the AAC then uses the second new TLV to deliver
identifier mappings from the AAC to the AAS. A primary feature of Auto Attach is to
facilitate the mapping of VLANs defined outside the SPB network onto service ids (ISIDs)
defined within the SPM network. By doing so individual external VLANs can be mapped onto
specific SPB network services. These VLAN id to ISID mappings can be configured and
managed locally using new options added to the ovs-vsctl command.

The Auto Attach OVS feature does not provide a full implementation of the LLDP protocol.
Support for the mandatory TLVs as defined by the LLDP standard and support for the AA TLV
extensions is provided. LLDP protocol support in OVS can be enabled or disabled on a port
by port basis. LLDP support is disabled by default.

Summary:
system_name string
system_description string
mappings map of integer-integer pairs, key in range 0 to 16,777,215,
value in range 0 to 4,095

Details:
system_name: string
The system_name string is exported in LLDP messages. It should uniquely identify
the bridge in the network.

system_description: string
The system_description string is exported in LLDP messages. It should describe the
type of software and hardware.

mappings: map of integer-integer pairs, key in range 0 to 16,777,215, value in range 0 to
4,095
A mapping from SPB network Individual Service Identifier (ISID) to VLAN id.