Provided by: openvswitch-switch_2.0.2-0ubuntu0.14.04.3_amd64 bug

NAME

       Open_vSwitch - 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.
       SSL       SSL configuration.
       sFlow     sFlow configuration.
       IPFIX     IPFIX configuration.
       Flow_Sample_Collector_Set
                 Flow_Sample_Collector_Set configuration.

Open_vSwitch TABLE

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

   Summary:
       Configuration:
         bridges                     set of Bridges
         ssl                         optional SSL
         external_ids : system-id    optional string
         external_ids : xs-system-uuid
                                     optional string
         other_config : flow-restore-wait
                                     optional string, either true or false
         other_config : flow-eviction-threshold
                                     optional string, containing an integer, at least 0
         other_config : force-miss-model
                                     optional string
         other_config : n-handler-threads
                                     optional string, containing an integer, at least 1
       Status:
         next_cfg                    integer
         cur_cfg                     integer
         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
       Database Configuration:
         manager_options             set of Managers
       Common Columns:
         other_config                map of string-string pairs
         external_ids                map of string-string pairs

   Details:
     Configuration:

       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.  On a Citrix XenServer, this will likely be the same as external_ids:xs-
              system-uuid.

       external_ids : xs-system-uuid: optional string
              The Citrix XenServer universally unique identifier for  the  physical  host  as  displayed  by  xe
              host-list.

       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.

              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-eviction-threshold: optional string, containing an integer, at least 0
              A  number of flows as a nonnegative integer.  This sets number of flows at which eviction from the
              datapath flow table will be triggered.  If there are a large number of flows then increasing  this
              value to around the number of flows present can result in reduced CPU usage and packet loss.

              The default is 2500.  Values below 100 will be rounded up to 100.

       other_config : force-miss-model: optional string
              Specifies  userspace behaviour for handling flow misses. This takes precedence over flow-eviction-
              threshold.

              auto   Handle automatically based on the  flow-eviction-threshold  and  the  flow  setup  governer
                     (default, recommended).

              with-facets
                     Always  create  facets.  Expensive  kernel  flow creation and statistics tracking is always
                     performed, even on flows with only a small number of packets.

              without-facets
                     Always handle without facets. Forces flow misses to be handled in userspace. May  cause  an
                     increase in CPU usage and packet loss on high throughput.

       other_config : n-handler-threads: optional string, containing an integer, at least 1
              Specifies the number of threads for software datapaths to use for handling new flows.  The default
              is two less than the number of online CPU cores (but at least 1).

              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.

     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.

     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 in  the  form  major.minor.tweak,  e.g.  1.2.3.   Whenever  the
              database  schema  is changed in a non-backward compatible way (e.g. deleting a column or a table),
              major is incremented.  When the database schema is changed in  a  backward  compatible  way  (e.g.
              adding  a  new  column),  minor  is incremented.  When the database schema is changed cosmetically
              (e.g. reindenting its syntax), tweak is incremented.

              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. XenServer or 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. 5.6.100-39265p on XenServer 5.6.100
              build 39265.

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

     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 connection should be configured.  See the Manager table
              for more information.

     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                        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
       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
         other_config : datapath-id  optional string
         other_config : dp-desc      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
         protocols                   set of strings, one of OpenFlow11, OpenFlow10, OpenFlow13, or OpenFlow12
       Spanning Tree 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 Features:
         datapath_type               string
         external_ids : bridge-id    optional string
         external_ids : xs-network-uuids
                                     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
       Bridge Status:
         status                      map of string-string pairs
         status : stp_bridge_id      optional string
         status : stp_designated_root
                                     optional string
         status : stp_root_path_cost
                                     optional string
       Common Columns:
         other_config                map of string-string pairs
         external_ids                map of string-string pairs

   Details:
     Core Features:

       name: string (must be unique within table)
              Bridge  identifier.   Should  be alphanumeric and no more than about 8 bytes long.  Must be unique
              among the names of ports, interfaces, and bridges on a host.

       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.

     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 flow table.   If  there  are  no
              primary  controllers,  adding  one  also  clears  the  flow  table.   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 the flow table.

       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).

              When  more  than  one  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 flow 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.)

       other_config : datapath-id: optional string
              Exactly 16 hex digits to set the OpenFlow datapath ID to a specific value.  May not be all-zero.

       other_config : dp-desc: optional string
              Human  readable  description  of  datapath.   It  it  a  maximum 256 byte-long free-form string to
              describe the datapath for debugging purposes, e.g. switch3 in room 3120.

       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.

       protocols: set of strings, one of OpenFlow11, OpenFlow10, OpenFlow13, or OpenFlow12
              List  of  OpenFlow  protocols that may be used when negotiating a connection with a controller.  A
              default value of OpenFlow10 will be used 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.

       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.

       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 Features:

       datapath_type: string
              Name of datapath provider.  The kernel datapath has type system.  The userspace datapath has  type
              netdev.

       external_ids : bridge-id: optional string
              A  unique  identifier  of  the  bridge.   On  Citrix  XenServer  this will commonly be the same as
              external_ids:xs-network-uuids.

       external_ids : xs-network-uuids: optional string
              Semicolon-delimited set of universally unique identifier(s) for the network with which this bridge
              is associated on a Citrix XenServer host.  The network identifiers are RFC 4122 UUIDs as displayed
              by, e.g., xe network-list.

       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
              Option  to  allow  forwarding  of BPDU frames when NORMAL action is invoked.  Frames with reserved
              Ethernet addresses (e.g. STP BPDU) will be forwarded when this option is enabled and the switch is
              not providing that functionality.  If STP is  enabled  on  the  port,  STP  BPDUs  will  never  be
              forwarded.  If the Open vSwitch bridge is used to connect different Ethernet networks, and if Open
              vSwitch  node  does  not run STP, then this option should be enabled.  Default is disabled, set to
              true to enable.  The following destination MAC addresss will not be forwarded when this option  is
              enabled.

              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  2048.   The  value,  if
              specified, is forced into a reasonable range, currently 10 to 1,000,000.

     Bridge Status:
       Status information about bridges.

       status: map of string-string pairs
              Key-value pairs that report bridge status.

       status : stp_bridge_id: optional string
              The  bridge-id  (in  hex)  used  in  spanning  tree  advertisements.  Configuring the bridge-id is
              described in the stp-system-id and stp-priority keys of the other_config section earlier.

       status : stp_designated_root: optional string
              The designated root (in hex) for this spanning tree.

       status : stp_root_path_cost: optional string
              The path cost of reaching the designated bridge.  A lower number is better.

     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                          string (must be unique within table)
       interfaces                    set of 1 or more Interfaces
       VLAN Configuration:
         vlan_mode                   optional string, one of access, 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
         other_config : priority-tags
                                     optional string, either true or false
       Bonding Configuration:
         bond_mode                   optional string, one of active-backup, balance-tcp, or balance-slb
         other_config : bond-hash-basis
                                     optional string, containing an integer
         Link Failure Detection:
            other_config : bond-detect-mode
                                     optional string, either miimon or carrier
            other_config : bond-miimon-interval
                                     optional string, containing an integer
            bond_updelay             integer
            bond_downdelay           integer
         LACP Configuration:
            lacp                     optional string, one of active, passive, or off
            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 slow or fast
         Rebalancing Configuration:
            other_config : bond-rebalance-interval
                                     optional string, containing an integer, in range 0 to 10,000
         bond_fake_iface             boolean
       Spanning Tree 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
       Other Features:
         qos                         optional QoS
         mac                         optional string
         fake_bridge                 boolean
         external_ids : fake-bridge-id-*
                                     optional string
       Port Status:
         status                      map of string-string pairs
         status : stp_port_id        optional string
         status : stp_state          optional  string,  one  of  disabled,  forwarding,  learning, listening, or
                                     blocking
         status : stp_sec_in_state   optional string, containing an integer, at least 0
         status : stp_role           optional string, one of designated, alternate, or root
       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: string (must be unique within table)
              Port name.  Should be alphanumeric and no more than about 8 bytes long.  May be the  same  as  the
              interface  name,  for  non-bonded  ports.   Must  otherwise  be  unique  among the names of ports,
              interfaces, and bridges on a host.

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

     VLAN Configuration:
       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.

       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, 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.

       other_config : priority-tags: optional string, either true or false
              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 true to enable
              priority-tagged frames on a port.

              Regardless of this setting, Open vSwitch omits the 802.1Q header on output if both the VLAN ID and
              priority would be zero.

              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  slaves  based  on source MAC address and output VLAN, with periodic
                     rebalancing as traffic patterns change.

              active-backup
                     Assigns all flows to one slave, failing over to a backup slave when  the  active  slave  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:

              balance-tcp
                     Balances flows among  slaves  based  on  L2,  L3,  and  L4  protocol  information  such  as
                     destination MAC address, IP address, and TCP port.

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

       bond_mode: optional string, one of active-backup, balance-tcp, or balance-slb
              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 slaves in load balanced bonds.  When
              changed, all flows will be  assigned  different  hash  values  possibly  causing  slave  selection
              decisions  to  change.   Does  not affect bonding modes which do not employ load balancing such as
              active-backup.

     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 miimon or carrier
              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, passive, or off
              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.  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 slow or fast
              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.

     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 10,000
              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 Configuration:

       other_config : stp-enable: optional string, either true or false
              If spanning tree is enabled on the bridge, member ports are enabled by default (with the exception
              of  bond, internal, and mirror ports which do not work with STP).  If this column’s value is false
              spanning tree 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.

     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.

       external_ids : fake-bridge-id-*: 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-xs-network-uuids.

     Port Status:
       Status information about ports attached to bridges.

       status: map of string-string pairs
              Key-value pairs that report port status.

       status : stp_port_id: optional string
              The port-id (in hex) used in spanning tree advertisements for this port.  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 disabled, forwarding, learning, listening, or blocking
              STP state of the port.

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

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

     Port Statistics:
       Key-value pairs that report port statistics.

     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                        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
         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 : key               optional string
         options : tos               optional string
         options : ttl               optional string
         options : df_default        optional string, either true or false
         Tunnel Options: gre and ipsec_gre only:
            options : csum           optional string, either true or false
         Tunnel Options: ipsec_gre only:
            options : peer_cert      optional string
            options : certificate    optional string
            options : private_key    optional string
            options : psk            optional string
       Patch Options:
         options : peer              optional string
       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
         mtu                         optional integer
         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
       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_burst      integer, at least 0
       Bidirectional Forwarding Detection (BFD):
         bfd : enable                optional string
         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_dst_mac           optional string
         bfd_status : state          optional string, one of down, init, up, or admin_down
         bfd_status : forwarding     optional string, either true or false
         bfd_status : diagnostic     optional string
         bfd_status : remote_state   optional string, one of down, init, up, or admin_down
         bfd_status : remote_diagnostic
                                     optional string
       Connectivity Fault Management:
         cfm_mpid                    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 : xs-vif-uuid  optional string
         external_ids : xs-network-uuid
                                     optional string
         external_ids : vm-id        optional string
         external_ids : xs-vm-uuid   optional string
       VLAN Splinters:
         other_config : enable-vlan-splinters
                                     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: string (must be unique within table)
              Interface name.  Should be alphanumeric and no more than about 8 bytes long.  May be the  same  as
              the  port  name,  for  non-bonded  ports.   Must  otherwise  be  unique  among the names of ports,
              interfaces, and bridges on a host.

       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  slave  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.

       ofport: optional integer
              OpenFlow port number for this interface.  Unlike most columns, this column’s value should  be  set
              only  by  Open vSwitch itself.  Other clients should set this column to an empty set (the default)
              when creating an Interface.

              Open vSwitch populates this column when the port  number  becomes  known.   If  the  interface  is
              successfully  added,  ofport  will be set to a number between 1 and 65535 (generally either in the
              range 1 to 65279, inclusive, or 65534, the port number for the OpenFlow ``local port’’).   If  the
              interface cannot be added then Open vSwitch sets this column to -1.

              When  ofport_request  is not set, Open vSwitch picks an appropriate value for this column and then
              tries to keep the value constant across restarts.

       ofport_request: optional integer, in range 1 to 65,279
              Requested OpenFlow port number for this interface.  The port number must be between 1  and  65279,
              inclusive.   Some  datapaths  cannot  satisfy all requests for particular port numbers.  When this
              column is empty or the request cannot be fulfilled, the system  will  choose  a  free  port.   The
              ofport column reports the assigned OpenFlow port number.

              The port number must be requested in the same transaction that creates the port.

     System-Specific Details:

       type: string
              The interface type, one of:

              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.

              gre    An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4 tunnel.

              ipsec_gre
                     An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4 IPsec tunnel.

              gre64  It  is  same  as GRE, but it allows 64 bit key. To store higher 32-bits of key, it uses GRE
                     protocol sequence number field. This is non standard use of GRE protocol since OVS does not
                     increment sequence number for every packet at time of encap as  expected  by  standard  GRE
                     implementation. See Tunnel Options for information on configuring GRE tunnels.

              ipsec_gre64
                     Same as IPSEC_GRE except 64 bit key.

              vxlan  An   Ethernet   tunnel  over  the  experimental,  UDP-based  VXLAN  protocol  described  at
                     http://tools.ietf.org/html/draft-mahalingam-dutt-dcops-vxlan-03.

                     Open vSwitch uses 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).

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

              null   An ignored interface. Deprecated and slated for removal in February 2013.

     Tunnel Options:
       These options apply to interfaces with type of gre, ipsec_gre, gre64, ipsec_gre64, vxlan, and lisp.

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

              •      An  IPv4  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 field.  When sending packets to a remote_ip=flow  tunnel,  the  flow  actions  must
                     explicitly  set  the tun_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 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 field.  When sending packets to a local_ip=flow tunnel,
                     the flow actions may explicitly set the tun_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 field for matching in the flow table.

       options : in_key: optional string
              Optional.  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 VXLAN and LISP), 32-bit (for GRE) or 64-bit (for GRE64) 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-ofctl manual page contains additional
                     information about matching fields in OpenFlow flows.

       options : out_key: optional string
              Optional.  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 VXLAN and LISP), 32-bit (for GRE)  or  64-bit  (for  GRE64)  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-ofctl
                     manual page contains additional information about the Nicira OpenFlow vendor extensions.

       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.

     Tunnel Options: gre and ipsec_gre only:
       Only gre and ipsec_gre interfaces support these options.

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

              GRE checksums impose a significant performance penalty because they cover the entire packet.   The
              encapsulated L3, L4, and L7 packet contents typically have their own checksums, so this additional
              checksum only adds value for the GRE and encapsulated L2 headers.

              This  option is supported for ipsec_gre, but not useful because GRE checksums are weaker than, and
              redundant with, IPsec payload authentication.

     Tunnel Options: ipsec_gre only:
       Only ipsec_gre interfaces support these options.

       options : peer_cert: optional string
              Required for certificate authentication.  A  string  containing  the  peer’s  certificate  in  PEM
              format.  Additionally the host’s certificate must be specified with the certificate option.

       options : certificate: optional string
              Required  for  certificate  authentication.   The name of a PEM file containing a certificate that
              will be presented to the peer during authentication.

       options : private_key: optional string
              Optional for certificate authentication.  The name of  a  PEM  file  containing  the  private  key
              associated with certificate.  If certificate contains the private key, this option may be omitted.

       options : psk: optional string
              Required  for  pre-shared  key authentication.  Specifies a pre-shared key for authentication that
              must be identical on both sides of the tunnel.

     Patch Options:
       Only patch interfaces support these options.

       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.

     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.

       mtu: optional integer
              The MTU (maximum transmission unit); i.e. 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.

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

       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 tunnel end-point, such as gre.

       status : tunnel_egress_iface: optional string
              Egress  interface  for  tunnels.   Currently  only relevant for GRE 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.

     Statistics:
       Key-value  pairs  that  report  interface  statistics.  The current implementation updates these counters
       periodically.  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 is currently implemented only on Linux.  The Linux implementation uses a simple ``token bucket’’
       approach:

              •      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.

       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_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 1000 kb.  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  10%  of
              ingress_policing_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.  It is implemented in Open vSwitch 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’s willing to transmit them.  Open vSwitch uses a detection multiplier of three, meaning
       that an endpoint which fails to receive BFD control messages for a period of  three  times  the  expected
       reception  rate,  will  signal a connectivity fault.  In the case of a unidirectional connectivity issue,
       the system not receiving BFD control messages will signal the problem to its  peer  in  the  messages  it
       transmits.

       The  Open  vSwitch implementation of BFD aims to comply faithfully with the requirements put forth in RFC
       5880.  Currently, the only known omission is ``Demand Mode’’, which we hope to include in  future.   Open
       vSwitch does not implement the optional Authentication or ``Echo Mode’’ features.

       bfd : enable: optional string
              When true BFD is enabled on this Interface, otherwise it’s disabled.  Defaults to false.

       bfd : min_rx: optional string, containing an integer, at least 1
              The  fastest  rate,  in  milliseconds, at which this BFD session is willing to receive BFD control
              messages.  The actual rate may be slower if the remote  endpoint  isn’t  willing  to  transmit  as
              quickly as specified.  Defaults to 1000.

       bfd : min_tx: optional string, containing an integer, at least 1
              The  fastest  rate,  in milliseconds, at which this BFD session is willing to transmit BFD control
              messages.  The actual rate may be slower if the  remote  endpoint  isn’t  willing  to  receive  as
              quickly as specified.  Defaults to 100.

       bfd : decay_min_rx: optional string, containing an integer
              decay_min_rx  is  used  to  set  the min_rx, when there is no obvious incoming data traffic at the
              interface.  It cannot be set less than the min_rx. The decay feature is disabled  by  setting  the
              decay_min_rx to 0. And the feature is reset everytime itself or min_rx is reconfigured.

       bfd : forwarding_if_rx: optional string, either true or false
              When  forwarding_if_rx  is  true the interface will be considered capable of packet I/O as long as
              there is packet received at interface.  This is important in that when  link  becomes  temporarily
              conjested, consecutive BFD control packets can be lost.  And the forwarding_if_rx can prevent link
              failover by detecting non-control packets received at interface.

       bfd : cpath_down: optional string, either true or false
              Concatenated  path  down may be used when the local system should not have traffic forwarded to it
              for some reason other than a connectivty  failure  on  the  interface  being  monitored.   When  a
              controller  thinks  this may be the case, it may set cpath_down to true which may cause the remote
              BFD session not to forward traffic to this Interface. Defaults to false.

       bfd : check_tnl_key: optional string, either true or false
              When set to true, Check Tunnel Key will make BFD only accept control messages with  an  in_key  of
              zero. Defaults to false.

       bfd : bfd_dst_mac: optional string
              An  Ethernet  address  in the form xx:xx:xx:xx:xx:xx to set the destination mac address of the bfd
              packet. If this field is set, it is assumed that all the bfd packets destined  to  this  interface
              also  has  the  same  destination mac address. If not set, a default value of 00:23:20:00:00:01 is
              used.

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

       bfd_status : forwarding: optional string, either true or false
              True if 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 short message indicating what the BFD session thinks is wrong in case of a problem.

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

       bfd_status : remote_diagnostic: optional string
              A short message indicating what the remote endpoint’s BFD session thinks is wrong  in  case  of  a
              problem.

     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.

       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.
              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, but if the Interface is receiving traffic, their absence does not cause
              a 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.
       For  a Citrix XenServer hypervisor, these values are UUIDs in RFC 4122 format.  Other hypervisors may use
       other formats.

       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.  For Citrix XenServer, this is the value of the MAC field in the VIF record for
              this interface.

       external_ids : iface-id: optional string
              A  system-unique  identifier  for  the interface.  On XenServer, this will commonly be the same as
              external_ids:xs-vif-uuid.

       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
              XenServer  has 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 : xs-vif-uuid: optional string
              The virtual interface associated with this interface.

       external_ids : xs-network-uuid: optional string
              The virtual network to which this interface is attached.

       external_ids : vm-id: optional string
              The VM to which this interface belongs. On XenServer, this will be the same as external_ids:xs-vm-
              uuid.

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

     VLAN Splinters:
       The  ``VLAN  splinters’’  feature  increases Open vSwitch compatibility with buggy network drivers in old
       versions of Linux that do not properly support VLANs when VLAN devices are not  used,  at  some  cost  in
       memory and performance.

       When  VLAN  splinters  are enabled on a particular interface, Open vSwitch creates a VLAN device for each
       in-use VLAN.  For sending traffic tagged with a VLAN on the interface, it substitutes  the  VLAN  device.
       Traffic  received  on  the  VLAN  device  is  treated  as if it had been received on the interface on the
       particular VLAN.

       VLAN splinters consider a VLAN to be in use if:

              •      The VLAN is the tag value in any Port record.

              •      The VLAN is listed within the trunks column of the Port record of  an  interface  on  which
                     VLAN  splinters are enabled.  An empty trunks does not influence the in-use VLANs: creating
                     4,096 VLAN devices is impractical because  it  will  exceed  the  current  1,024  port  per
                     datapath limit.

              •      An OpenFlow flow within any bridge matches the VLAN.

       The  same  set  of in-use VLANs applies to every interface on which VLAN splinters are enabled.  That is,
       the set is not chosen separately for each interface but selected once as the union of  all  in-use  VLANs
       based on the rules above.

       It  does  not  make sense to enable VLAN splinters on an interface for an access port, or on an interface
       that is not a physical port.

       VLAN splinters are deprecated.  When broken device drivers are no  longer  in  widespread  use,  we  will
       delete this feature.

       other_config : enable-vlan-splinters: optional string, either true or false
              Set to true to enable VLAN splinters on this interface.  Defaults to false.

              VLAN  splinters  increase kernel and userspace memory overhead, so do not use them unless they are
              needed.

              VLAN splinters do not support 802.1p priority tags.  Received priorities  will  appear  to  be  0,
              regardless  of  their actual values, and priorities on transmitted packets will also be cleared to
              0.

     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
       flow_limit                    optional integer, at least 0
       overflow_policy               optional string, either refuse or evict
       groups                        set of strings

   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.

       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 refuse or evict
              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 the flow that will expire soonest.  See groups for details.

       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
              nicira-ext.h for a complete list of NXM field names.

              When a flow must be evicted due to overflow, the flow to evict is chosen through an  approximation
              of the following algorithm:

              1.
                Divide  the  flows  in  the  table  into  groups  based on the values of the specified fields or
                subfields, 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.

              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.
                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.)

              Open vSwitch ignores any invalid or unknown field specifications.

              When overflow_policy is not evict, this column has no effect.

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
       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.

       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 100 Mbps.

     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.

   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
       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.

     Statistics: Mirror counters:
       Key-value pairs that report mirror statistics.

       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.

       Open vSwitch supports two kinds of OpenFlow controllers:

              Primary controllers
                     This  is  the  kind of controller envisioned by the OpenFlow 1.0 specification.  Usually, a
                     primary controller implements a network policy by taking charge of the switch’s flow table.

                     Open vSwitch  initiates  and  maintains  persistent  connections  to  primary  controllers,
                     retrying  the  connection  each time it fails or drops.  The fail_mode column in the Bridge
                     table applies to primary controllers.

                     Open vSwitch permits a bridge to have any number of  primary  controllers.   When  multiple
                     controllers  are  configured, Open vSwitch connects to all of them simultaneously.  Because
                     OpenFlow 1.0 does not specify how multiple controllers coordinate  in  interacting  with  a
                     single switch, more than one primary controller should be specified only if the controllers
                     are  themselves  designed  to  coordinate  with  each  other.  (The Nicira-defined NXT_ROLE
                     OpenFlow vendor extension may be useful for this.)

              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.

                     Open vSwitch listens for  incoming  connections  from  service  controllers.   The  service
                     controllers  initiate  and,  if  necessary,  maintain  the connections from their end.  The
                     fail_mode column in the Bridge table does not apply to service controllers.

                     Open vSwitch supports configuring any number of service controllers.

       The target determines the type of controller.

   Summary:
       Core Features:
         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 Message Configuration:
         enable_async_messages       optional boolean
         controller_rate_limit       optional integer, at least 100
         controller_burst_limit      optional integer, at least 25
       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 slave, other, or master
         status : last_error         optional string
         status : state              optional string, one of ACTIVE, VOID, CONNECTING, IDLE, or BACKOFF
         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:

       target: string
              Connection method for controller.

              The following connection methods are currently supported for primary controllers:

              ssl:ip[:port]
                     The specified SSL port (default: 6633) on the host at the given ip, which must be expressed
                     as an IP address (not a DNS name).  The ssl column in the Open_vSwitch table must point  to
                     a valid SSL configuration when this form is used.

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

              tcp:ip[:port]
                     The specified TCP port (default: 6633) on the host at the given ip, which must be expressed
                     as an IP address (not a DNS name).

              The following connection methods are currently supported for service controllers:

              pssl:[port][:ip]
                     Listens  for  SSL connections on the specified TCP port (default: 6633).  If ip, which must
                     be expressed as an IP address  (not  a  DNS  name),  is  specified,  then  connections  are
                     restricted to the specified local IP address.

                     The  ssl column in the Open_vSwitch table must point to a valid SSL configuration when this
                     form is used.

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

              ptcp:[port][:ip]
                     Listens for connections on the specified TCP port (default: 6633).  If ip,  which  must  be
                     expressed  as an IP address (not a DNS name), is specified, then connections are restricted
                     to the specified local IP address.

              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 Message Configuration:
       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_limit: optional integer, at least 100
              The  maximum  rate at which the switch will forward packets to the OpenFlow controller, in packets
              per second.  This feature prevents a single bridge  from  overwhelming  the  controller.   If  not
              specified, the default is implementation-specific.

              In  addition,  when a high rate triggers rate-limiting, Open vSwitch queues controller packets for
              each port and transmits them to the controller at the configured rate.  The controller_burst_limit
              value limits the number of queued packets.  Ports on a bridge share the packet queue fairly.

              Open vSwitch maintains two such packet rate-limiters per bridge: one for packets sent  up  to  the
              controller  because  they  do not correspond to any flow, and the other for packets sent up to the
              controller by request through flow actions. When both rate-limiters are filled with  packets,  the
              actual rate that packets are sent to the controller is up to twice the specified rate.

       controller_burst_limit: optional integer, at least 25
              In  conjunction  with  controller_rate_limit, the maximum number of unused packet credits that the
              bridge will allow to accumulate, in packets.  If not specified,  the  default  is  implementation-
              specific.

     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 slave, other, or master
              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  master  controller  at  a  time.
                     When  a  controller  configures  itself  as  master,  any existing master is demoted to the
                     slaverole.

              slave  Allows the controller read-only access to OpenFlow features.  Attempts to modify  the  flow
                     table  will  be rejected with an error.  Slave 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, VOID, CONNECTING, IDLE, or BACKOFF
              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, VOID, CONNECTING, IDLE, or BACKOFF
         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:

              ssl:ip[:port]
                     The specified SSL port (default: 6632) on the host at the given ip, which must be expressed
                     as an IP address (not a DNS name).  The ssl column in the Open_vSwitch table must point  to
                     a valid SSL configuration when this form is used.

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

              tcp:ip[:port]
                     The specified TCP port (default: 6632) on the host at the given ip, which must be expressed
                     as an IP address (not a DNS name).

              pssl:[port][:ip]
                     Listens  for SSL connections on the specified TCP port (default: 6632).  Specify 0 for port
                     to have the kernel automatically choose an available port.  If ip, which must be  expressed
                     as  an  IP  address  (not a DNS name), is specified, then connections are restricted to the
                     specified local IP address.

                     The ssl column in the Open_vSwitch table must point to a valid SSL configuration when  this
                     form is used.

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

              ptcp:[port][:ip]
                     Listens  for  connections on the specified TCP port (default: 6632).  Specify 0 for port to
                     have the kernel automatically choose an available port.  If ip, which must be expressed  as
                     an  IP  address  (not  a  DNS  name),  is specified, then connections are restricted to the
                     specified local IP address.

              When multiple managers are configured, 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 OVSDB client over the network:

              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:

       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, VOID, CONNECTING, IDLE, or BACKOFF
              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.

              When multiple connections are active, status columns and key-value pairs  (other  than  this  one)
              report the status of one arbitrarily chosen connection.

       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  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.

       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

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
              Name  of  the  network  device  whose  IP  address  should be reported as the ``agent address’’ to
              collectors.  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 any of these ways, 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

       A set of IPFIX collectors.  IPFIX is a protocol that exports a number of details about flows.

   Summary:
       targets                       set of 1 or more strings
       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
       cache_active_timeout          optional integer, in range 0 to 4,200
       cache_max_flows               optional integer, in range 0 to 4,294,967,295
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       targets: set of 1 or more strings
              IPFIX target collectors in the form ip:port.

       sampling: optional integer, in range 1 to 4,294,967,295
              For per-bridge packet sampling, i.e. when this row is referenced from a Bridge, 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.   Ignored
              for per-flow sampling, i.e. when this row is referenced from a Flow_Sample_Collector_Set.

       obs_domain_id: optional integer, in range 0 to 4,294,967,295
              For  per-bridge  packet  sampling,  i.e.  when  this  row  is  referenced from a Bridge, the IPFIX
              Observation Domain ID sent in each IPFIX packet.  If not specified, defaults to  0.   Ignored  for
              per-flow sampling, i.e. when this row is referenced from a Flow_Sample_Collector_Set.

       obs_point_id: optional integer, in range 0 to 4,294,967,295
              For  per-bridge  packet  sampling,  i.e.  when  this  row  is  referenced from a Bridge, the IPFIX
              Observation Point ID sent in each IPFIX flow record.  If not specified, defaults  to  0.   Ignored
              for per-flow sampling, i.e. when this row is referenced from a Flow_Sample_Collector_Set.

       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.

     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.

   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

Open vSwitch                                          2.0.2                              ovs-vswitchd.conf.db(5)