Provided by: openvswitch-common_2.5.9-0ubuntu0.16.04.3_amd64 
NAME
ovs-ofctl - administer OpenFlow switches
SYNOPSIS
ovs-ofctl [options] command [switch] [args...]
DESCRIPTION
The ovs-ofctl program is a command line tool for monitoring and administering OpenFlow switches. It can
also show the current state of an OpenFlow switch, including features, configuration, and table entries.
It should work with any OpenFlow switch, not just Open vSwitch.
OpenFlow Switch Management Commands
These commands allow ovs-ofctl to monitor and administer an OpenFlow switch. It is able to show the
current state of a switch, including features, configuration, and table entries.
Most of these commands take an argument that specifies the method for connecting to an OpenFlow switch.
The following connection methods are supported:
ssl:ip[:port]
tcp:ip[:port]
The specified port on the host at the given ip, which must be expressed as an IP address
(not a DNS name) in IPv4 or IPv6 address format. Wrap IPv6 addresses in square brackets,
e.g. tcp:[::1]:6653. For ssl, the --private-key, --certificate, and --ca-cert options are
mandatory.
If port is not specified, it defaults to 6653.
unix:file
On POSIX, a Unix domain server socket named file.
On Windows, a localhost TCP port written in file.
file This is short for unix:file, as long as file does not contain a colon.
bridge This is short for unix:/var/run/openvswitch/bridge.mgmt, as long as bridge does not contain
a colon.
[type@]dp
Attempts to look up the bridge associated with dp and open as above. If type is given, it
specifies the datapath provider of dp, otherwise the default provider system is assumed.
show switch
Prints to the console information on switch, including information on its flow tables and ports.
dump-tables switch
Prints to the console statistics for each of the flow tables used by switch.
dump-table-features switch
Prints to the console features for each of the flow tables used by switch.
dump-table-desc switch
Prints to the console configuration for each of the flow tables used by switch for OpenFlow 1.4+.
mod-table switch table_id setting
This command configures flow table settings for OpenFlow table table_id within switch. The
available settings depend on the OpenFlow version in use. In OpenFlow 1.1 and 1.2 (which must be
enabled with the -O option) only, mod-table configures behavior when no flow is found when a
packet is looked up in a flow table. The following setting values are available:
drop Drop the packet.
continue
Continue to the next table in the pipeline. (This is how an OpenFlow 1.0 switch always
handles packets that do not match any flow, in tables other than the last one.)
controller
Send to controller. (This is how an OpenFlow 1.0 switch always handles packets that do not
match any flow in the last table.)
In OpenFlow 1.4 and later (which must be enabled with the -O option) only, mod-table configures
the behavior when a controller attempts to add a flow to a flow table that is full. The following
setting values are available:
evict Delete some existing flow from the flow table, according to the algorithm described for the
Flow_Table table in ovs-vswitchd.conf.db(5).
noevict
Refuse to add the new flow. (Eviction might still be enabled through the overflow_policy
column in the Flow_Table table documented in ovs-vswitchd.conf.db(5).)
vacancy:low,high
Enables sending vacancy events to controllers using TABLE_STATUS messages, based on
percentage thresholds low and high.
novacancy
Disables vacancy events.
dump-ports switch [netdev]
Prints to the console statistics for network devices associated with switch. If netdev is
specified, only the statistics associated with that device will be printed. netdev can be an
OpenFlow assigned port number or device name, e.g. eth0.
dump-ports-desc switch [port]
Prints to the console detailed information about network devices associated with switch. To dump
only a specific port, specify its number as port. Otherwise, if port is omitted, or if it is
specified as ANY, then all ports are printed. This is a subset of the information provided by the
show command.
If the connection to switch negotiates OpenFlow 1.0, 1.2, or 1.2, this command uses an OpenFlow
extension only implemented in Open vSwitch (version 1.7 and later).
Only OpenFlow 1.5 and later support dumping a specific port. Earlier versions of OpenFlow always
dump all ports.
mod-port switch port action
Modify characteristics of port port in switch. port may be an OpenFlow port number or name or the
keyword LOCAL (the preferred way to refer to the OpenFlow local port). The action may be any one
of the following:
up
down Enable or disable the interface. This is equivalent to ifconfig up or ifconfig down on a
Unix system.
stp
no-stp Enable or disable 802.1D spanning tree protocol (STP) on the interface. OpenFlow
implementations that don't support STP will refuse to enable it.
receive
no-receive
receive-stp
no-receive-stp
Enable or disable OpenFlow processing of packets received on this interface. When packet
processing is disabled, packets will be dropped instead of being processed through the
OpenFlow table. The receive or no-receive setting applies to all packets except 802.1D
spanning tree packets, which are separately controlled by receive-stp or no-receive-stp.
forward
no-forward
Allow or disallow forwarding of traffic to this interface. By default, forwarding is
enabled.
flood
no-flood
Controls whether an OpenFlow flood action will send traffic out this interface. By
default, flooding is enabled. Disabling flooding is primarily useful to prevent loops when
a spanning tree protocol is not in use.
packet-in
no-packet-in
Controls whether packets received on this interface that do not match a flow table entry
generate a ``packet in'' message to the OpenFlow controller. By default, ``packet in''
messages are enabled.
The show command displays (among other information) the configuration that mod-port changes.
get-frags switch
Prints switch's fragment handling mode. See set-frags, below, for a description of each fragment
handling mode.
The show command also prints the fragment handling mode among its other output.
set-frags switch frag_mode
Configures switch's treatment of IPv4 and IPv6 fragments. The choices for frag_mode are:
normal Fragments pass through the flow table like non-fragmented packets. The TCP ports, UDP
ports, and ICMP type and code fields are always set to 0, even for fragments where that
information would otherwise be available (fragments with offset 0). This is the default
fragment handling mode for an OpenFlow switch.
drop Fragments are dropped without passing through the flow table.
reassemble
The switch reassembles fragments into full IP packets before passing them through the flow
table. Open vSwitch does not implement this fragment handling mode.
nx-match
Fragments pass through the flow table like non-fragmented packets. The TCP ports, UDP
ports, and ICMP type and code fields are available for matching for fragments with offset
0, and set to 0 in fragments with nonzero offset. This mode is a Nicira extension.
See the description of ip_frag, below, for a way to match on whether a packet is a fragment and on
its fragment offset.
dump-flows switch [flows]
Prints to the console all flow entries in switch's tables that match flows. If flows is omitted,
all flows in the switch are retrieved. See Flow Syntax, below, for the syntax of flows. The
output format is described in Table Entry Output.
By default, ovs-ofctl prints flow entries in the same order that the switch sends them, which is
unlikely to be intuitive or consistent. See the description of --sort and --rsort, under OPTIONS
below, to influence the display order.
dump-aggregate switch [flows]
Prints to the console aggregate statistics for flows in switch's tables that match flows. If
flows is omitted, the statistics are aggregated across all flows in the switch's flow tables. See
Flow Syntax, below, for the syntax of flows. The output format is described in Table Entry
Output.
queue-stats switch [port [queue]]
Prints to the console statistics for the specified queue on port within switch. port can be an
OpenFlow port number or name, the keyword LOCAL (the preferred way to refer to the OpenFlow local
port), or the keyword ALL. Either of port or queue or both may be omitted (or equivalently the
keyword ALL). If both are omitted, statistics are printed for all queues on all ports. If only
queue is omitted, then statistics are printed for all queues on port; if only port is omitted,
then statistics are printed for queue on every port where it exists.
OpenFlow 1.1+ Group Table Commands
The following commands work only with switches that support OpenFlow 1.1 or later. Because support for
OpenFlow 1.1 and later is still experimental in Open vSwitch, it is necessary to explicitly enable these
protocol versions in ovs-ofctl (using -O) and in the switch itself (with the protocols column in the
Bridge table). For more information, see ``Q: What versions of OpenFlow does Open vSwitch support?'' in
the Open vSwitch FAQ.
dump-groups switch [group]
Prints group entries in switch's tables to console. To dump only a specific group, specify its
number as group. Otherwise, if group is omitted, or if it is specified as ALL, then all groups
are printed. Each line of output is a group entry as described in Group Syntax below.
Only OpenFlow 1.5 and later support dumping a specific group. Earlier versions of OpenFlow always
dump all groups.
dump-group-features switch
Prints to the console the group features of the switch.
dump-group-stats switch [groups]
Prints to the console statistics for the specified groups in the switch's tables. If groups is
omitted then statistics for all groups are printed. See Group Syntax, below, for the syntax of
groups.
OpenFlow 1.3+ Switch Meter Table Commands
These commands manage the meter table in an OpenFlow switch. In each case, meter specifies a meter entry
in the format described in Meter Syntax, below.
OpenFlow 1.3 introduced support for meters, so these commands only work with switches that support
OpenFlow 1.3 or later. The caveats described for groups in the previous section also apply to meters.
add-meter switch meter
Add a meter entry to switch's tables. The meter syntax is described in section Meter Syntax,
below.
mod-meter switch meter
Modify an existing meter.
del-meters switch
del-meter switch [meter]
Delete entries from switch's meter table. meter can specify a single meter with syntax meter=id,
or all meters with syntax meter=all.
dump-meters switch
dump-meter switch [meter]
Print meter configuration. meter can specify a single meter with syntax meter=id, or all meters
with syntax meter=all.
meter-stats switch [meter]
Print meter statistics. meter can specify a single meter with syntax meter=id, or all meters with
syntax meter=all.
meter-features switch
Print meter features.
OpenFlow Switch Flow Table Commands
These commands manage the flow table in an OpenFlow switch. In each case, flow specifies a flow entry in
the format described in Flow Syntax, below, file is a text file that contains zero or more flows in the
same syntax, one per line, and the optional --bundle option operates the command as a single atomic
transation, see option --bundle, below.
[--bundle] add-flow switch flow
[--bundle] add-flow switch - < file
[--bundle] add-flows switch file
Add each flow entry to switch's tables. Each flow specification (e.g., each line in file) may
start with add, modify, delete, modify_strict, or delete_strict keyword to specify whether a flow
is to be added, modified, or deleted, and whether the modify or delete is strict or not. For
backwards compatibility a flow specification without one of these keywords is treated as a flow
add. All flow mods are executed in the order specified.
[--bundle] [--strict] mod-flows switch flow
[--bundle] [--strict] mod-flows switch - < file
Modify the actions in entries from switch's tables that match the specified flows. With --strict,
wildcards are not treated as active for matching purposes.
[--bundle] del-flows switch
[--bundle] [--strict] del-flows switch [flow]
[--bundle] [--strict] del-flows switch - < file
Deletes entries from switch's flow table. With only a switch argument, deletes all flows.
Otherwise, deletes flow entries that match the specified flows. With --strict, wildcards are not
treated as active for matching purposes.
[--bundle] [--readd] replace-flows switch file
Reads flow entries from file (or stdin if file is -) and queries the flow table from switch. Then
it fixes up any differences, adding flows from flow that are missing on switch, deleting flows
from switch that are not in file, and updating flows in switch whose actions, cookie, or timeouts
differ in file.
With --readd, ovs-ofctl adds all the flows from file, even those that exist with the same actions,
cookie, and timeout in switch. This resets all the flow packet and byte counters to 0, which can
be useful for debugging.
diff-flows source1 source2
Reads flow entries from source1 and source2 and prints the differences. A flow that is in source1
but not in source2 is printed preceded by a -, and a flow that is in source2 but not in source1 is
printed preceded by a +. If a flow exists in both source1 and source2 with different actions,
cookie, or timeouts, then both versions are printed preceded by - and +, respectively.
source1 and source2 may each name a file or a switch. If a name begins with / or ., then it is
considered to be a file name. A name that contains : is considered to be a switch. Otherwise, it
is a file if a file by that name exists, a switch if not.
For this command, an exit status of 0 means that no differences were found, 1 means that an error
occurred, and 2 means that some differences were found.
packet-out switch in_port actions packet...
Connects to switch and instructs it to execute the OpenFlow actions on each packet. Each packet
is specified as a series of hex digits. For the purpose of executing the actions, the packets are
considered to have arrived on in_port, which may be an OpenFlow port number or name (e.g. eth0),
the keyword LOCAL (the preferred way to refer to the OpenFlow ``local'' port), or the keyword NONE
to indicate that the packet was generated by the switch itself.
OpenFlow Switch Group Table Commands
These commands manage the group table in an OpenFlow switch. In each case, group specifies a group entry
in the format described in Group Syntax, below, and file is a text file that contains zero or more groups
in the same syntax, one per line.
add-group switch group
add-group switch - < file
add-groups switch file
Add each group entry to switch's tables.
mod-group switch group
mod-group switch - < file
Modify the action buckets in entries from switch's tables for each group entry.
del-groups switch
del-groups switch [group]
del-groups switch - < file
Deletes entries from switch's group table. With only a switch argument, deletes all groups.
Otherwise, deletes the group for each group entry.
insert-buckets switch group
insert-buckets switch - < file
Add buckets to an existing group present in the switch's group table. If no command_bucket_id is
present in the group specification then all buckets of the group are removed.
remove-buckets switch group
remove-buckets switch - < file
Remove buckets to an existing group present in the switch's group table. If no command_bucket_id
is present in the group specification then all buckets of the group are removed.
OpenFlow Switch Tunnel TLV Table Commands
Open vSwitch maintains a mapping table between tunnel option TLVs (defined by <class, type, length>) and
NXM fields tun_metadatan, where n ranges from 0 to 63, that can be operated on for the purposes of
matches, actions, etc. This TLV table can be used for Geneve option TLVs or other protocols with options
in same TLV format as Geneve options. This mapping must be explicitly specified by the user through the
following commands.
A TLV mapping is specified with the syntax {class=class,type=type,len=length}->tun_metadatan. When an
option mapping exists for a given tun_metadatan, matching on the defined field becomes possible, e.g.:
ovs-ofctl add-tlv-map br0 "{class=0xffff,type=0,len=4}->tun_metadata0"
ovs-ofctl add-flow br0 tun_metadata0=1234,actions=controller
A mapping should not be changed while it is in active use by a flow. The result of doing so is undefined.
Currently, the TLV mapping table is shared between all OpenFlow switches in a given instance of Open
vSwitch. This restriction will be lifted in the future to allow for easier management.
These commands are Nicira extensions to OpenFlow and require Open vSwitch 2.5 or later.
add-tlv-map switch option[,option]...
Add each option to switch's tables. Duplicate fields are rejected.
del-tlv-map switch [option[,option]]...
Delete each option from switch's table, or all option TLV mapping if no option is specified.
Fields that aren't mapped are ignored.
dump-tlv-map switch
Show the currently mapped fields in the switch's option table as well as switch capabilities.
OpenFlow Switch Monitoring Commands
snoop switch
Connects to switch and prints to the console all OpenFlow messages received. Unlike other
ovs-ofctl commands, if switch is the name of a bridge, then the snoop command connects to a Unix
domain socket named /var/run/openvswitch/switch.snoop. ovs-vswitchd listens on such a socket for
each bridge and sends to it all of the OpenFlow messages sent to or received from its configured
OpenFlow controller. Thus, this command can be used to view OpenFlow protocol activity between a
switch and its controller.
When a switch has more than one controller configured, only the traffic to and from a single
controller is output. If none of the controllers is configured as a master or a slave (using a
Nicira extension to OpenFlow 1.0 or 1.1, or a standard request in OpenFlow 1.2 or later), then a
controller is chosen arbitrarily among them. If there is a master controller, it is chosen;
otherwise, if there are any controllers that are not masters or slaves, one is chosen arbitrarily;
otherwise, a slave controller is chosen arbitrarily. This choice is made once at connection time
and does not change as controllers reconfigure their roles.
If a switch has no controller configured, or if the configured controller is disconnected, no
traffic is sent, so monitoring will not show any traffic.
monitor switch [miss-len] [invalid_ttl] [watch:[spec...]]
Connects to switch and prints to the console all OpenFlow messages received. Usually, switch
should specify the name of a bridge in the ovs-vswitchd database.
If miss-len is provided, ovs-ofctl sends an OpenFlow ``set configuration'' message at connection
setup time that requests miss-len bytes of each packet that misses the flow table. Open vSwitch
does not send these and other asynchronous messages to an ovs-ofctl monitor client connection
unless a nonzero value is specified on this argument. (Thus, if miss-len is not specified, very
little traffic will ordinarily be printed.)
If invalid_ttl is passed, ovs-ofctl sends an OpenFlow ``set configuration'' message at connection
setup time that requests INVALID_TTL_TO_CONTROLLER, so that ovs-ofctl monitor can receive
``packet-in'' messages when TTL reaches zero on dec_ttl action.
watch:[spec...] causes ovs-ofctl to send a ``monitor request'' Nicira extension message to the
switch at connection setup time. This message causes the switch to send information about flow
table changes as they occur. The following comma-separated spec syntax is available:
!initial
Do not report the switch's initial flow table contents.
!add Do not report newly added flows.
!delete
Do not report deleted flows.
!modify
Do not report modifications to existing flows.
!own Abbreviate changes made to the flow table by ovs-ofctl's own connection to the switch.
(These could only occur using the ofctl/send command described below under RUNTIME
MANAGEMENT COMMANDS.)
!actions
Do not report actions as part of flow updates.
table=number
Limits the monitoring to the table with the given number between 0 and 254. By default,
all tables are monitored.
out_port=port
If set, only flows that output to port are monitored. The port may be an OpenFlow port
number or keyword (e.g. LOCAL).
field=value
Monitors only flows that have field specified as the given value. Any syntax valid for
matching on dump-flows may be used.
This command may be useful for debugging switch or controller implementations. With watch:, it is
particularly useful for observing how a controller updates flow tables.
OpenFlow Switch and Controller Commands
The following commands, like those in the previous section, may be applied to OpenFlow switches, using
any of the connection methods described in that section. Unlike those commands, these may also be
applied to OpenFlow controllers.
probe target
Sends a single OpenFlow echo-request message to target and waits for the response. With the -t or
--timeout option, this command can test whether an OpenFlow switch or controller is up and
running.
ping target [n]
Sends a series of 10 echo request packets to target and times each reply. The echo request
packets consist of an OpenFlow header plus n bytes (default: 64) of randomly generated payload.
This measures the latency of individual requests.
benchmark target n count
Sends count echo request packets that each consist of an OpenFlow header plus n bytes of payload
and waits for each response. Reports the total time required. This is a measure of the maximum
bandwidth to target for round-trips of n-byte messages.
Other Commands
ofp-parse file
Reads file (or stdin if file is -) as a series of OpenFlow messages in the binary format used on
an OpenFlow connection, and prints them to the console. This can be useful for printing OpenFlow
messages captured from a TCP stream.
ofp-parse-pcap file [port...]
Reads file, which must be in the PCAP format used by network capture tools such as tcpdump or
wireshark, extracts all the TCP streams for OpenFlow connections, and prints the OpenFlow messages
in those connections in human-readable format on stdout.
OpenFlow connections are distinguished by TCP port number. Non-OpenFlow packets are ignored. By
default, data on TCP ports 6633 and 6653 are considered to be OpenFlow. Specify one or more port
arguments to override the default.
This command cannot usefully print SSL encrypted traffic. It does not understand IPv6.
Flow Syntax
Some ovs-ofctl commands accept an argument that describes a flow or flows. Such flow descriptions
comprise a series field=value assignments, separated by commas or white space. (Embedding spaces into a
flow description normally requires quoting to prevent the shell from breaking the description into
multiple arguments.)
Flow descriptions should be in normal form. This means that a flow may only specify a value for an L3
field if it also specifies a particular L2 protocol, and that a flow may only specify an L4 field if it
also specifies particular L2 and L3 protocol types. For example, if the L2 protocol type dl_type is
wildcarded, then L3 fields nw_src, nw_dst, and nw_proto must also be wildcarded. Similarly, if dl_type
or nw_proto (the L3 protocol type) is wildcarded, so must be the L4 fields tcp_dst and tcp_src.
ovs-ofctl will warn about flows not in normal form.
The following field assignments describe how a flow matches a packet. If any of these assignments is
omitted from the flow syntax, the field is treated as a wildcard; thus, if all of them are omitted, the
resulting flow matches all packets. The string * may be specified to explicitly mark any of these fields
as a wildcard. (* should be quoted to protect it from shell expansion.)
in_port=port
Matches OpenFlow port port, which may be an OpenFlow port number or keyword (e.g. LOCAL).
ovs-ofctl show.
(The resubmit action can search OpenFlow flow tables with arbitrary in_port values, so flows that
match port numbers that do not exist from an OpenFlow perspective can still potentially be
matched.)
dl_vlan=vlan
Matches IEEE 802.1q Virtual LAN tag vlan. Specify 0xffff as vlan to match packets that are not
tagged with a Virtual LAN; otherwise, specify a number between 0 and 4095, inclusive, as the
12-bit VLAN ID to match.
dl_vlan_pcp=priority
Matches IEEE 802.1q Priority Code Point (PCP) priority, which is specified as a value between 0
and 7, inclusive. A higher value indicates a higher frame priority level.
dl_src=xx:xx:xx:xx:xx:xx
dl_dst=xx:xx:xx:xx:xx:xx
Matches an Ethernet source (or destination) address specified as 6 pairs of hexadecimal digits
delimited by colons (e.g. 00:0A:E4:25:6B:B0).
dl_src=xx:xx:xx:xx:xx:xx/xx:xx:xx:xx:xx:xx
dl_dst=xx:xx:xx:xx:xx:xx/xx:xx:xx:xx:xx:xx
Matches an Ethernet destination address specified as 6 pairs of hexadecimal digits delimited by
colons (e.g. 00:0A:E4:25:6B:B0), with a wildcard mask following the slash. Open vSwitch 1.8 and
later support arbitrary masks for source and/or destination. Earlier versions only support masking
the destination with the following masks:
01:00:00:00:00:00
Match only the multicast bit. Thus, dl_dst=01:00:00:00:00:00/01:00:00:00:00:00 matches all
multicast (including broadcast) Ethernet packets, and
dl_dst=00:00:00:00:00:00/01:00:00:00:00:00 matches all unicast Ethernet packets.
fe:ff:ff:ff:ff:ff
Match all bits except the multicast bit. This is probably not useful.
ff:ff:ff:ff:ff:ff
Exact match (equivalent to omitting the mask).
00:00:00:00:00:00
Wildcard all bits (equivalent to dl_dst=*.)
dl_type=ethertype
Matches Ethernet protocol type ethertype, which is specified as an integer between 0 and 65535,
inclusive, either in decimal or as a hexadecimal number prefixed by 0x (e.g. 0x0806 to match ARP
packets).
nw_src=ip[/netmask]
nw_dst=ip[/netmask]
When dl_type is 0x0800 (possibly via shorthand, e.g. ip or tcp), matches IPv4 source (or
destination) address ip, which may be specified as an IP address or host name (e.g. 192.168.1.1 or
www.example.com). The optional netmask allows restricting a match to an IPv4 address prefix. The
netmask may be specified as a dotted quad (e.g. 192.168.1.0/255.255.255.0) or as a CIDR block
(e.g. 192.168.1.0/24). Open vSwitch 1.8 and later support arbitrary dotted quad masks; earlier
versions support only CIDR masks, that is, the dotted quads that are equivalent to some CIDR
block.
When dl_type=0x0806 or arp is specified, matches the ar_spa or ar_tpa field, respectively, in ARP
packets for IPv4 and Ethernet.
When dl_type=0x8035 or rarp is specified, matches the ar_spa or ar_tpa field, respectively, in
RARP packets for IPv4 and Ethernet.
When dl_type is wildcarded or set to a value other than 0x0800, 0x0806, or 0x8035, the values of
nw_src and nw_dst are ignored (see Flow Syntax above).
nw_proto=proto
ip_proto=proto
When ip or dl_type=0x0800 is specified, matches IP protocol type proto, which is specified as a
decimal number between 0 and 255, inclusive (e.g. 1 to match ICMP packets or 6 to match TCP
packets).
When ipv6 or dl_type=0x86dd is specified, matches IPv6 header type proto, which is specified as a
decimal number between 0 and 255, inclusive (e.g. 58 to match ICMPv6 packets or 6 to match TCP).
The header type is the terminal header as described in the DESIGN document.
When arp or dl_type=0x0806 is specified, matches the lower 8 bits of the ARP opcode. ARP opcodes
greater than 255 are treated as 0.
When rarp or dl_type=0x8035 is specified, matches the lower 8 bits of the ARP opcode. ARP opcodes
greater than 255 are treated as 0.
When dl_type is wildcarded or set to a value other than 0x0800, 0x0806, 0x8035 or 0x86dd, the
value of nw_proto is ignored (see Flow Syntax above).
nw_tos=tos
Matches IP ToS/DSCP or IPv6 traffic class field tos, which is specified as a decimal number
between 0 and 255, inclusive. Note that the two lower reserved bits are ignored for matching
purposes.
When dl_type is wildcarded or set to a value other than 0x0800 or 0x86dd, the value of nw_tos is
ignored (see Flow Syntax above).
ip_dscp=dscp
Matches IP ToS/DSCP or IPv6 traffic class field dscp, which is specified as a decimal number
between 0 and 63, inclusive.
When dl_type is wildcarded or set to a value other than 0x0800 or 0x86dd, the value of ip_dscp is
ignored (see Flow Syntax above).
nw_ecn=ecn
ip_ecn=ecn
Matches ecn bits in IP ToS or IPv6 traffic class fields, which is specified as a decimal number
between 0 and 3, inclusive.
When dl_type is wildcarded or set to a value other than 0x0800 or 0x86dd, the value of nw_ecn is
ignored (see Flow Syntax above).
nw_ttl=ttl
Matches IP TTL or IPv6 hop limit value ttl, which is specified as a decimal number between 0 and
255, inclusive.
When dl_type is wildcarded or set to a value other than 0x0800 or 0x86dd, the value of nw_ttl is
ignored (see Flow Syntax above).
tcp_src=port
tcp_dst=port
udp_src=port
udp_dst=port
sctp_src=port
sctp_dst=port
Matches a TCP, UDP, or SCTP source or destination port port, which is specified as a decimal
number between 0 and 65535, inclusive.
When dl_type and nw_proto are wildcarded or set to values that do not indicate an appropriate
protocol, the values of these settings are ignored (see Flow Syntax above).
tcp_src=port/mask
tcp_dst=port/mask
udp_src=port/mask
udp_dst=port/mask
sctp_src=port/mask
sctp_dst=port/mask
Bitwise match on TCP (or UDP or SCTP) source or destination port. The port and mask are 16-bit
numbers written in decimal or in hexadecimal prefixed by 0x. Each 1-bit in mask requires that the
corresponding bit in port must match. Each 0-bit in mask causes the corresponding bit to be
ignored.
Bitwise matches on transport ports are rarely useful in isolation, but a group of them can be used
to reduce the number of flows required to match on a range of transport ports. For example,
suppose that the goal is to match TCP source ports 1000 to 1999, inclusive. One way is to insert
1000 flows, each of which matches on a single source port. Another way is to look at the binary
representations of 1000 and 1999, as follows:
01111101000
11111001111
and then to transform those into a series of bitwise matches that accomplish the same results:
01111101xxx
0111111xxxx
10xxxxxxxxx
110xxxxxxxx
1110xxxxxxx
11110xxxxxx
1111100xxxx
which become the following when written in the syntax required by ovs-ofctl:
tcp,tcp_src=0x03e8/0xfff8
tcp,tcp_src=0x03f0/0xfff0
tcp,tcp_src=0x0400/0xfe00
tcp,tcp_src=0x0600/0xff00
tcp,tcp_src=0x0700/0xff80
tcp,tcp_src=0x0780/0xffc0
tcp,tcp_src=0x07c0/0xfff0
Only Open vSwitch 1.6 and later supports bitwise matching on transport ports.
Like the exact-match forms described above, the bitwise match forms apply only when dl_type and
nw_proto specify TCP or UDP or SCTP.
tp_src=port
tp_dst=port
These are deprecated generic forms of L4 port matches. In new code, please use the TCP-, UDP-, or
SCTP-specific forms described above.
tcp_flags=flags/mask
tcp_flags=[+flag...][-flag...]
Bitwise match on TCP flags. The flags and mask are 16-bit numbers written in decimal or in
hexadecimal prefixed by 0x. Each 1-bit in mask requires that the corresponding bit in flags must
match. Each 0-bit in mask causes the corresponding bit to be ignored.
Alternatively, the flags can be specified by their symbolic names (listed below), each preceded by
either + for a flag that must be set, or - for a flag that must be unset, without any other
delimiters between the flags. Flags not mentioned are wildcarded. For example,
tcp,tcp_flags=+syn-ack matches TCP SYNs that are not ACKs.
TCP protocol currently defines 9 flag bits, and additional 3 bits are reserved (must be
transmitted as zero), see RFCs 793, 3168, and 3540. The flag bits are, numbering from the least
significant bit:
0: fin No more data from sender.
1: syn Synchronize sequence numbers.
2: rst Reset the connection.
3: psh Push function.
4: ack Acknowledgement field significant.
5: urg Urgent pointer field significant.
6: ece ECN Echo.
7: cwr Congestion Windows Reduced.
8: ns Nonce Sum.
9-11: Reserved.
12-15: Not matchable, must be zero.
icmp_type=type
icmp_code=code
When dl_type and nw_proto specify ICMP or ICMPv6, type matches the ICMP type and code matches the
ICMP code. Each is specified as a decimal number between 0 and 255, inclusive.
When dl_type and nw_proto take other values, the values of these settings are ignored (see Flow
Syntax above).
table=number
For flow dump commands, limits the flows dumped to those in the table with the given number
between 0 and 254. If not specified (or if 255 is specified as number), then flows in all tables
are dumped.
For flow table modification commands, behavior varies based on the OpenFlow version used to
connect to the switch:
OpenFlow 1.0
OpenFlow 1.0 does not support table for modifying flows. ovs-ofctl will exit with an error
if table (other than table=255) is specified for a switch that only supports OpenFlow 1.0.
In OpenFlow 1.0, the switch chooses the table into which to insert a new flow. The Open
vSwitch software switch always chooses table 0. Other Open vSwitch datapaths and other
OpenFlow implementations may choose different tables.
The OpenFlow 1.0 behavior in Open vSwitch for modifying or removing flows depends on
whether --strict is used. Without --strict, the command applies to matching flows in all
tables. With --strict, the command will operate on any single matching flow in any table;
it will do nothing if there are matches in more than one table. (The distinction between
these behaviors only matters if non-OpenFlow 1.0 commands were also used, because OpenFlow
1.0 alone cannot add flows with the same matching criteria to multiple tables.)
OpenFlow 1.0 with table_id extension
Open vSwitch implements an OpenFlow extension that allows the controller to specify the
table on which to operate. ovs-ofctl automatically enables the extension when table is
specified and OpenFlow 1.0 is used. ovs-ofctl automatically detects whether the switch
supports the extension. As of this writing, this extension is only known to be implemented
by Open vSwitch.
With this extension, ovs-ofctl operates on the requested table when table is specified, and
acts as described for OpenFlow 1.0 above when no table is specified (or for table=255).
OpenFlow 1.1
OpenFlow 1.1 requires flow table modification commands to specify a table. When table is
not specified (or table=255 is specified), ovs-ofctl defaults to table 0.
OpenFlow 1.2 and later
OpenFlow 1.2 and later allow flow deletion commands, but not other flow table modification
commands, to operate on all flow tables, with the behavior described above for OpenFlow
1.0.
metadata=value[/mask]
Matches value either exactly or with optional mask in the metadata field. value and mask are
64-bit integers, by default in decimal (use a 0x prefix to specify hexadecimal). Arbitrary mask
values are allowed: a 1-bit in mask indicates that the corresponding bit in value must match
exactly, and a 0-bit wildcards that bit. Matching on metadata was added in Open vSwitch 1.8.
The following shorthand notations are also available:
ip Same as dl_type=0x0800.
ipv6 Same as dl_type=0x86dd.
icmp Same as dl_type=0x0800,nw_proto=1.
icmp6 Same as dl_type=0x86dd,nw_proto=58.
tcp Same as dl_type=0x0800,nw_proto=6.
tcp6 Same as dl_type=0x86dd,nw_proto=6.
udp Same as dl_type=0x0800,nw_proto=17.
udp6 Same as dl_type=0x86dd,nw_proto=17.
sctp Same as dl_type=0x0800,nw_proto=132.
sctp6 Same as dl_type=0x86dd,nw_proto=132.
arp Same as dl_type=0x0806.
rarp Same as dl_type=0x8035.
mpls Same as dl_type=0x8847.
mplsm Same as dl_type=0x8848.
The following field assignments require support for the NXM (Nicira Extended Match) extension to
OpenFlow. When one of these is specified, ovs-ofctl will automatically attempt to negotiate use of this
extension. If the switch does not support NXM, then ovs-ofctl will report a fatal error.
vlan_tci=tci[/mask]
Matches modified VLAN TCI tci. If mask is omitted, tci is the exact VLAN TCI to match; if mask is
specified, then a 1-bit in mask indicates that the corresponding bit in tci must match exactly,
and a 0-bit wildcards that bit. Both tci and mask are 16-bit values that are decimal by default;
use a 0x prefix to specify them in hexadecimal.
The value that vlan_tci matches against is 0 for a packet that has no 802.1Q header. Otherwise,
it is the TCI value from the 802.1Q header with the CFI bit (with value 0x1000) forced to 1.
Examples:
vlan_tci=0
Match only packets without an 802.1Q header.
vlan_tci=0xf123
Match packets tagged with priority 7 in VLAN 0x123.
vlan_tci=0x1123/0x1fff
Match packets tagged with VLAN 0x123 (and any priority).
vlan_tci=0x5000/0xf000
Match packets tagged with priority 2 (in any VLAN).
vlan_tci=0/0xfff
Match packets with no 802.1Q header or tagged with VLAN 0 (and any priority).
vlan_tci=0x5000/0xe000
Match packets with no 802.1Q header or tagged with priority 2 (in any VLAN).
vlan_tci=0/0xefff
Match packets with no 802.1Q header or tagged with VLAN 0 and priority 0.
Some of these matching possibilities can also be achieved with dl_vlan and dl_vlan_pcp.
ip_frag=frag_type
When dl_type specifies IP or IPv6, frag_type specifies what kind of IP fragments or non-fragments
to match. The following values of frag_type are supported:
no Matches only non-fragmented packets.
yes Matches all fragments.
first Matches only fragments with offset 0.
later Matches only fragments with nonzero offset.
not_later
Matches non-fragmented packets and fragments with zero offset.
The ip_frag match type is likely to be most useful in nx-match mode. See the description of the
set-frags command, above, for more details.
arp_spa=ip[/netmask]
arp_tpa=ip[/netmask]
When dl_type specifies either ARP or RARP, arp_spa and arp_tpa match the source and target IPv4
address, respectively. An address may be specified as an IP address or host name (e.g.
192.168.1.1 or www.example.com). The optional netmask allows restricting a match to an IPv4
address prefix. The netmask may be specified as a dotted quad (e.g. 192.168.1.0/255.255.255.0) or
as a CIDR block (e.g. 192.168.1.0/24).
arp_sha=xx:xx:xx:xx:xx:xx
arp_tha=xx:xx:xx:xx:xx:xx
When dl_type specifies either ARP or RARP, arp_sha and arp_tha match the source and target
hardware address, respectively. An address is specified as 6 pairs of hexadecimal digits
delimited by colons (e.g. 00:0A:E4:25:6B:B0).
arp_sha=xx:xx:xx:xx:xx:xx/xx:xx:xx:xx:xx:xx
arp_tha=xx:xx:xx:xx:xx:xx/xx:xx:xx:xx:xx:xx
When dl_type specifies either ARP or RARP, arp_sha and arp_tha match the source and target
hardware address, respectively. An address is specified as 6 pairs of hexadecimal digits
delimited by colons (e.g. 00:0A:E4:25:6B:B0), with a wildcard mask following the slash.
arp_op=opcode
When dl_type specifies either ARP or RARP, arp_op matches the ARP opcode. Only ARP opcodes
between 1 and 255 should be specified for matching.
ipv6_src=ipv6[/netmask]
ipv6_dst=ipv6[/netmask]
When dl_type is 0x86dd (possibly via shorthand, e.g., ipv6 or tcp6), matches IPv6 source (or
destination) address ipv6, which may be specified as defined in RFC 2373. The preferred format is
x:x:x:x:x:x:x:x, where x are the hexadecimal values of the eight 16-bit pieces of the address. A
single instance of :: may be used to indicate multiple groups of 16-bits of zeros. The optional
netmask allows restricting a match to an IPv6 address prefix. A netmask is specified as an IPv6
address (e.g. 2001:db8:3c4d:1::/ffff:ffff:ffff:ffff::) or a CIDR block (e.g.
2001:db8:3c4d:1::/64). Open vSwitch 1.8 and later support arbitrary masks; earlier versions
support only CIDR masks, that is, CIDR block and IPv6 addresses that are equivalent to CIDR
blocks.
ipv6_label=label
When dl_type is 0x86dd (possibly via shorthand, e.g., ipv6 or tcp6), matches IPv6 flow label
label.
nd_target=ipv6[/netmask]
When dl_type, nw_proto, and icmp_type specify IPv6 Neighbor Discovery (ICMPv6 type 135 or 136),
matches the target address ipv6. ipv6 is in the same format described earlier for the ipv6_src
and ipv6_dst fields.
nd_sll=xx:xx:xx:xx:xx:xx
When dl_type, nw_proto, and icmp_type specify IPv6 Neighbor Solicitation (ICMPv6 type 135),
matches the source link-layer address option. An address is specified as 6 pairs of hexadecimal
digits delimited by colons.
nd_tll=xx:xx:xx:xx:xx:xx
When dl_type, nw_proto, and icmp_type specify IPv6 Neighbor Advertisement (ICMPv6 type 136),
matches the target link-layer address option. An address is specified as 6 pairs of hexadecimal
digits delimited by colons.
mpls_bos=bos
When dl_type is 0x8847 or 0x8848 (possibly via shorthand e.g., mpls or mplsm), matches the bottom-
of-stack bit of the outer-most MPLS label stack entry. Valid values are 0 and 1.
If 1 then for a packet with a well-formed MPLS label stack the bottom-of-stack bit indicates that
the outer label stack entry is also the inner-most label stack entry and thus that is that there
is only one label stack entry present. Conversely, if 0 then for a packet with a well-formed MPLS
label stack the bottom-of-stack bit indicates that the outer label stack entry is not the inner-
most label stack entry and thus there is more than one label stack entry present.
mpls_label=label
When dl_type is 0x8847 or 0x8848 (possibly via shorthand e.g., mpls or mplsm), matches the label
of the outer MPLS label stack entry. The label is a 20-bit value that is decimal by default; use a
0x prefix to specify them in hexadecimal.
mpls_tc=tc
When dl_type is 0x8847 or 0x8848 (possibly via shorthand e.g., mpls or mplsm), matches the
traffic-class of the outer MPLS label stack entry. Valid values are between 0 (lowest) and 7
(highest).
tun_id=tunnel-id[/mask]
tunnel_id=tunnel-id[/mask]
Matches tunnel identifier tunnel-id. Only packets that arrive over a tunnel that carries a key
(e.g. GRE with the RFC 2890 key extension and a nonzero key value) will have a nonzero tunnel ID.
If mask is omitted, tunnel-id is the exact tunnel ID to match; if mask is specified, then a 1-bit
in mask indicates that the corresponding bit in tunnel-id must match exactly, and a 0-bit
wildcards that bit.
tun_flags=flags
Matches flags indicating various aspects of the tunnel encapsulation. Currently, there is only one
flag defined:
oam: The tunnel protocol indicated that this is an OAM control packet.
Flags can be prefixed by + or - to indicate that the flag should be matched as either present or
not present, respectively. In addition, flags can be specified without a prefix and separated by |
to indicate an exact match.
Note that it is possible for newer version of Open vSwitch to introduce additional flags with
varying meaning. It is therefore not recommended to use an exact match on this field since the
behavior of these new flags is unknown and should be ignored.
For non-tunneled packets, the value is 0.
This field was introduced in Open vSwitch 2.5.
tun_src=ip[/netmask]
tun_dst=ip[/netmask]
Matches tunnel IPv4 source (or destination) address ip. Only packets that arrive over a tunnel
will have nonzero tunnel addresses. The address may be specified as an IP address or host name
(e.g. 192.168.1.1 or www.example.com). The optional netmask allows restricting a match to a
masked IPv4 address. The netmask may be specified as a dotted quad (e.g.
192.168.1.0/255.255.255.0) or as a CIDR block (e.g. 192.168.1.0/24).
tun_gbp_id=value[/mask]
tun_gbp_flags=value[/mask]
Matches the group policy identifier and flags in the VXLAN header. Only packets that arrive over a
VXLAN tunnel with the "gbp" extension enabled can have this field set. The fields may also be
referred to by NXM_NX_TUN_GBP_ID[] (16 bits) and NXM_NX_TUN_GBP_FLAGS[] (8 bits) in the context of
field manipulation actions. If these fields are set and the packet matched by the flow is
encapsulated in a VXLAN-GBP tunnel, then the policy identifier and flags are transmitted to the
destination VXLAN tunnel endpoint.
The tun_gbp_flags field has the following format:
+-+-+-+-+-+-+-+-+
|-|D|-|-|A|-|-|-|
+-+-+-+-+-+-+-+-+
D := Don't Learn bit. When set, this bit indicates that the egress tunnel endpoint MUST NOT
learn the source address of the encapsulated frame.
A := Indicates that the group policy has already been applied to this packet. Policies MUST NOT
be applied by devices when the A bit is set.
For more information, please see the corresponding IETF draft: https://tools.ietf.org/html/draft-
smith-vxlan-group-policy
tun_metadataidx[=value[/mask]]
Matches value either exactly or with optional mask in tunnel metadata field number idx (numbered
from 0 to 63). The act of specifying a field implies a match on the existence of that field in
the packet in addition to the masked value. As a shorthand, it is possible to specify only the
field name to simply match on an option being present.
Tunnel metadata fields can be dynamically assigned onto the data contained in the option TLVs of
packets (e.g. Geneve variable options stores zero or more options in TLV format and tunnel
metadata can be assigned onto these option TLVs) using the commands described in the section
OpenFlow Switch Tunnel TLV Table Commands. Once assigned, the length of the field is variable
according to the size of the option. Before updating a mapping in the option table, flows with
references to it should be removed, otherwise the result is non-deterministic.
These fields were introduced in Open vSwitch 2.5.
regidx=value[/mask]
Matches value either exactly or with optional mask in register number idx. The valid range of idx
depends on the switch. value and mask are 32-bit integers, by default in decimal (use a 0x prefix
to specify hexadecimal). Arbitrary mask values are allowed: a 1-bit in mask indicates that the
corresponding bit in value must match exactly, and a 0-bit wildcards that bit.
When a packet enters an OpenFlow switch, all of the registers are set to 0. Only explicit actions
change register values.
xregidx=value[/mask]
Matches value either exactly or with optional mask in 64-bit ``extended register'' number idx.
Each of the 64-bit extended registers overlays two of the 32-bit registers: xreg0 overlays reg0
and reg1, with reg0 supplying the most-significant bits of xreg0 and reg1 the least-significant.
xreg1 similarly overlays reg2 and reg3, and so on.
These fields were added in Open vSwitch 2.3 to conform with the OpenFlow 1.5 specification.
OpenFlow 1.5 calls these fields just the ``packet registers,'' but Open vSwitch already had 32-bit
registers by that name, which is why Open vSwitch refers to the standard registers as ``extended
registers''.
pkt_mark=value[/mask]
Matches packet metadata mark value either exactly or with optional mask. The mark is associated
data that may be passed into other system components in order to facilitate interaction between
subsystems. On Linux this corresponds to the skb mark but the exact implementation is platform-
dependent.
actset_output=port
Matches the output port currently in the OpenFlow action set, where port may be an OpenFlow port
number or keyword (e.g. LOCAL). If there is no output port in the OpenFlow action set, or if the
output port will be ignored (e.g. because there is an output group in the OpenFlow action set),
then the value will be UNSET.
This field was introduced in Open vSwitch 2.4 to conform with the OpenFlow 1.5 specification.
conj_id=value
Matches the given 32-bit value against the conjunction ID. This is used only with the conjunction
action (see below).
This field was introduced in Open vSwitch 2.4.
ct_state=flags/mask
ct_state=[+flag...][-flag...]
Bitwise match on connection state flags. This is used with the ct action (see below).
The ct_state field provides information from a connection tracking module. It describes whether
the packet has previously traversed the connection tracker (tracked, or trk) and, if it has been
tracked, any additional information that the connection tracker was able to provide about the
connection that the current packet belongs to.
Individual packets may be in one of two states: Untracked or tracked. When the ct action is
executed on a packet, it becomes tracked for the the remainder of OpenFlow pipeline processing.
Once a packet has become tracked, the state of its corresponding connection may be determined.
Note that the ct_state is only significant for the current ct_zone.
Connections may be in one of two states: uncommitted or committed. Connections are uncommitted by
default. To determine ongoing information about a connection, like whether the connection is
established or not, the connection must be committed. When the ct action is executed on a packet
with the commit parameter, the connection will become committed and will remain in this state
until the end of the connection. Committed connections store state beyond the duration of packet
processing.
The flags and mask are 32-bit numbers written in decimal or in hexadecimal prefixed by 0x. Each
1-bit in mask requires that the corresponding bit in flags must match. Each 0-bit in mask causes
the corresponding bit to be ignored.
Alternatively, the flags can be specified by their symbolic names (listed below), each preceded by
either + for a flag that must be set, or - for a flag that must be unset, without any other
delimiters between the flags. Flags not mentioned are wildcarded. For example,
tcp,ct_state=+trk-new matches TCP packets that have been run through the connection tracker and do
not establish a new connection.
The following flags describe the state of the tracking:
0x01: new
This is the beginning of a new connection. This flag may only be present for uncommitted
connections.
0x02: est
This is part of an already existing connection. This flag may only be present for committed
connections.
0x04: rel
This is a connection that is related to an existing connection, for instance ICMP
"destination unreachable" messages or FTP data connections. This flag may only be present
for committed connections.
0x08: rpl
The flow is in the reply direction, meaning it did not initiate the connection. This flag
may only be present for committed connections.
0x10: inv
The state is invalid, meaning that the connection tracker couldn't identify the connection.
This flag is a catch-all for any problems that the connection tracker may have, for
example:
- L3/L4 protocol handler is not loaded/unavailable. With the Linux kernel datapath, this
may mean that the "nf_conntrack_ipv4" or "nf_conntrack_ipv6" modules are not loaded.
- L3/L4 protocol handler determines that the packet is malformed.
- Packets are unexpected length for protocol.
0x20: trk
This packet is tracked, meaning that it has previously traversed the connection tracker. If
this flag is not set, then no other flags will be set. If this flag is set, then the packet
is tracked and other flags may also be set.
This field was introduced in Open vSwitch 2.5.
The following fields are associated with the connection tracker and will only be populated for tracked
packets. The ct action will populate these fields, and allows modification of some of the below fields.
ct_zone=zone
Matches the given 16-bit connection zone exactly. This represents the most recent connection
tracking context that ct was executed in. Each zone is an independent connection tracking context,
so if you wish to track the same packet in multiple contexts then you must use the ct action
multiple times. Introduced in Open vSwitch 2.5.
ct_mark=value[/mask]
Matches the given 32-bit connection mark value either exactly or with optional mask. This
represents metadata associated with the connection that the current packet is part of. Introduced
in Open vSwitch 2.5.
ct_label=value[/mask]
Matches the given 128-bit connection labels value either exactly or with optional mask. This
represents metadata associated with the connection that the current packet is part of. Introduced
in Open vSwitch 2.5.
Defining IPv6 flows (those with dl_type equal to 0x86dd) requires support for NXM. The following
shorthand notations are available for IPv6-related flows:
ipv6 Same as dl_type=0x86dd.
tcp6 Same as dl_type=0x86dd,nw_proto=6.
udp6 Same as dl_type=0x86dd,nw_proto=17.
sctp6 Same as dl_type=0x86dd,nw_proto=132.
icmp6 Same as dl_type=0x86dd,nw_proto=58.
Finally, field assignments to duration, n_packets, or n_bytes are ignored to allow output from the
dump-flows command to be used as input for other commands that parse flows.
The add-flow, add-flows, and mod-flows commands require an additional field, which must be the final
field specified:
actions=[action][,action...]
Specifies a comma-separated list of actions to take on a packet when the flow entry matches. If
no action is specified, then packets matching the flow are dropped. The following forms of action
are supported:
port
output:port
Outputs the packet to OpenFlow port number port. If port is the packet's input port, the
packet is not output.
output:src[start..end]
Outputs the packet to the OpenFlow port number read from src, which must be an NXM field as
described above. For example, output:NXM_NX_REG0[16..31] outputs to the OpenFlow port
number written in the upper half of register 0. If the port number is the packet's input
port, the packet is not output.
This form of output was added in Open vSwitch 1.3.0. This form of output uses an OpenFlow
extension that is not supported by standard OpenFlow switches.
group:group_id
Outputs the packet to the OpenFlow group group_id. Group tables are only supported in
OpenFlow 1.1+. See Group Syntax for more details.
normal Subjects the packet to the device's normal L2/L3 processing. (This action is not
implemented by all OpenFlow switches.)
flood Outputs the packet on all switch physical ports other than the port on which it was
received and any ports on which flooding is disabled (typically, these would be ports
disabled by the IEEE 802.1D spanning tree protocol).
all Outputs the packet on all switch physical ports other than the port on which it was
received.
local Outputs the packet on the ``local port,'' which corresponds to the network device that has
the same name as the bridge.
in_port
Outputs the packet on the port from which it was received.
controller(key=value...)
Sends the packet to the OpenFlow controller as a ``packet in'' message. The supported key-
value pairs are:
max_len=nbytes
Limit to nbytes the number of bytes of the packet to send to the controller. By
default the entire packet is sent.
reason=reason
Specify reason as the reason for sending the message in the ``packet in'' message.
The supported reasons are action (the default), no_match, and invalid_ttl.
id=controller-id
Specify controller-id, a 16-bit integer, as the connection ID of the OpenFlow
controller or controllers to which the ``packet in'' message should be sent. The
default is zero. Zero is also the default connection ID for each controller
connection, and a given controller connection will only have a nonzero connection ID
if its controller uses the NXT_SET_CONTROLLER_ID Nicira extension to OpenFlow.
Any reason other than action and any nonzero controller-id uses a Nicira vendor extension
that, as of this writing, is only known to be implemented by Open vSwitch (version 1.6 or
later).
controller
controller[:nbytes]
Shorthand for controller() or controller(max_len=nbytes), respectively.
enqueue(port,queue)
Enqueues the packet on the specified queue within port port, which must be an OpenFlow port
number or keyword (e.g. LOCAL). The number of supported queues depends on the switch; some
OpenFlow implementations do not support queuing at all.
drop Discards the packet, so no further processing or forwarding takes place. If a drop action
is used, no other actions may be specified.
mod_vlan_vid:vlan_vid
Modifies the VLAN id on a packet. The VLAN tag is added or modified as necessary to match
the value specified. If the VLAN tag is added, a priority of zero is used (see the
mod_vlan_pcp action to set this).
mod_vlan_pcp:vlan_pcp
Modifies the VLAN priority on a packet. The VLAN tag is added or modified as necessary to
match the value specified. Valid values are between 0 (lowest) and 7 (highest). If the
VLAN tag is added, a vid of zero is used (see the mod_vlan_vid action to set this).
strip_vlan
Strips the VLAN tag from a packet if it is present.
push_vlan:ethertype
Push a new VLAN tag onto the packet. Ethertype is used as the Ethertype for the tag. Only
ethertype 0x8100 should be used. (0x88a8 which the spec allows isn't supported at the
moment.) A priority of zero and the tag of zero are used for the new tag.
push_mpls:ethertype
Changes the packet's Ethertype to ethertype, which must be either 0x8847 or 0x8848, and
pushes an MPLS LSE.
If the packet does not already contain any MPLS labels then an initial label stack entry is
pushed. The label stack entry's label is 2 if the packet contains IPv6 and 0 otherwise,
its default traffic control value is the low 3 bits of the packet's DSCP value (0 if the
packet is not IP), and its TTL is copied from the IP TTL (64 if the packet is not IP).
If the packet does already contain an MPLS label, pushes a new outermost label as a copy of
the existing outermost label.
A limitation of the implementation is that processing of actions will stop if push_mpls
follows another push_mpls unless there is a pop_mpls in between.
pop_mpls:ethertype
Strips the outermost MPLS label stack entry. Currently the implementation restricts
ethertype to a non-MPLS Ethertype and thus pop_mpls should only be applied to packets with
an MPLS label stack depth of one. A further limitation is that processing of actions will
stop if pop_mpls follows another pop_mpls unless there is a push_mpls in between.
mod_dl_src:mac
Sets the source Ethernet address to mac.
mod_dl_dst:mac
Sets the destination Ethernet address to mac.
mod_nw_src:ip
Sets the IPv4 source address to ip.
mod_nw_dst:ip
Sets the IPv4 destination address to ip.
mod_tp_src:port
Sets the TCP or UDP or SCTP source port to port.
mod_tp_dst:port
Sets the TCP or UDP or SCTP destination port to port.
mod_nw_tos:tos
Sets the DSCP bits in the IPv4 ToS/DSCP or IPv6 traffic class field to tos, which must be a
multiple of 4 between 0 and 255. This action does not modify the two least significant
bits of the ToS field (the ECN bits).
mod_nw_ecn:ecn
Sets the ECN bits in the IPv4 ToS or IPv6 traffic class field to ecn, which must be a value
between 0 and 3, inclusive. This action does not modify the six most significant bits of
the field (the DSCP bits).
Requires OpenFlow 1.1 or later.
mod_nw_ttl:ttl
Sets the IPv4 TTL or IPv6 hop limit field to ttl, which is specified as a decimal number
between 0 and 255, inclusive. Switch behavior when setting ttl to zero is not well
specified, though.
Requires OpenFlow 1.1 or later.
The following actions are Nicira vendor extensions that, as of this writing, are only known to be
implemented by Open vSwitch:
resubmit:port
resubmit([port],[table])
Re-searches this OpenFlow flow table (or the table whose number is specified by table) with
the in_port field replaced by port (if port is specified) and executes the actions found,
if any, in addition to any other actions in this flow entry.
Recursive resubmit actions are obeyed up to an implementation-defined maximum depth. Open
vSwitch 1.0.1 and earlier did not support recursion; Open vSwitch before 1.2.90 did not
support table.
set_tunnel:id
set_tunnel64:id
If outputting to a port that encapsulates the packet in a tunnel and supports an identifier
(such as GRE), sets the identifier to id. If the set_tunnel form is used and id fits in 32
bits, then this uses an action extension that is supported by Open vSwitch 1.0 and later.
Otherwise, if id is a 64-bit value, it requires Open vSwitch 1.1 or later.
set_queue:queue
Sets the queue that should be used to queue when packets are output. The number of
supported queues depends on the switch; some OpenFlow implementations do not support
queuing at all.
pop_queue
Restores the queue to the value it was before any set_queue actions were applied.
ct
ct([argument][,argument...])
Send the packet through the connection tracker. Refer to the ct_state documentation above
for possible packet and connection states. The following arguments are supported:
commit
Commit the connection to the connection tracking module. Information about the
connection will be stored beyond the lifetime of the packet in the pipeline. Some
ct_state flags are only available for committed connections.
table=number
Fork pipeline processing in two. The original instance of the packet will continue
processing the current actions list as an untracked packet. An additional instance
of the packet will be sent to the connection tracker, which will be re-injected into
the OpenFlow pipeline to resume processing in table number, with the ct_state and
other ct match fields set. If the table is not specified, then the packet which is
submitted to the connection tracker is not re-injected into the OpenFlow pipeline.
It is strongly recommended to specify a table later than the current table to
prevent loops.
zone=value
zone=src[start..end]
A 16-bit context id that can be used to isolate connections into separate domains,
allowing overlapping network addresses in different zones. If a zone is not
provided, then the default is to use zone zero. The zone may be specified either as
an immediate 16-bit value, or may be provided from an NXM field src. The start and
end pair are inclusive, and must specify a 16-bit range within the field. This value
is copied to the ct_zone match field for packets which are re-injected into the
pipeline using the table option.
exec([action][,action...])
Perform actions within the context of connection tracking. This is a restricted set
of actions which are in the same format as their specifications as part of a flow.
Only actions which modify the ct_mark or ct_label fields are accepted within the
exec action, and these fields may only be modified with this option. For example:
set_field:value[/mask]->ct_mark
Store a 32-bit metadata value with the connection. If the connection is
committed, then subsequent lookups for packets in this connection will
populate the ct_mark flow field when the packet is sent to the connection
tracker with the table specified.
set_field:value[/mask]->ct_label
Store a 128-bit metadata value with the connection. If the connection is
committed, then subsequent lookups for packets in this connection will
populate the ct_label flow field when the packet is sent to the connection
tracker with the table specified.
The commit parameter should be specified to use exec(...).
alg=alg
Specify application layer gateway alg to track specific connection types. Supported
types include:
ftp Look for negotiation of FTP data connections. If a subsequent FTP data
connection arrives which is related, the ct action will set the rel flag in
the ct_state field for packets sent through ct.
When committing related connections, the ct_mark for that connection is inherited
from the current ct_mark stored with the original connection (ie, the connection
created by ct(alg=...)).
The ct action may be used as a primitive to construct stateful firewalls by selectively
committing some traffic, then matching the ct_state to allow established connections while
denying new connections. The following flows provide an example of how to implement a
simple firewall that allows new connections from port 1 to port 2, and only allows
established connections to send traffic from port 2 to port 1:
table=0,priority=1,action=drop
table=0,priority=10,arp,action=normal
table=0,priority=100,ip,ct_state=-trk,action=ct(table=1)
table=1,in_port=1,ip,ct_state=+trk+new,action=ct(commit),2
table=1,in_port=1,ip,ct_state=+trk+est,action=2
table=1,in_port=2,ip,ct_state=+trk+new,action=drop
table=1,in_port=2,ip,ct_state=+trk+est,action=1
If ct is executed on IP (or IPv6) fragments, then the message is implicitly reassembled
before sending to the connection tracker and refragmented upon output, to the original
maximum received fragment size. Reassembly occurs within the context of the zone, meaning
that IP fragments in different zones are not assembled together. Pipeline processing for
the initial fragments is halted; When the final fragment is received, the message is
assembled and pipeline processing will continue for that flow. Because packet ordering is
not guaranteed by IP protocols, it is not possible to determine which IP fragment will
cause message reassembly (and therefore continue pipeline processing). As such, it is
strongly recommended that multiple flows should not execute ct to reassemble fragments from
the same IP message.
Currently, connection tracking is only available on Linux kernels with the nf_conntrack
module loaded. The ct action was introduced in Open vSwitch 2.5.
dec_ttl
dec_ttl(id1[,id2]...)
Decrement TTL of IPv4 packet or hop limit of IPv6 packet. If the TTL or hop limit is
initially zero or decrementing would make it so, no decrement occurs, as packets reaching
TTL zero must be rejected. Instead, a ``packet-in'' message with reason code
OFPR_INVALID_TTL is sent to each connected controller that has enabled receiving them, if
any. Processing the current set of actions then stops. However, if the current set of
actions was reached through ``resubmit'' then remaining actions in outer levels resume
processing.
This action also optionally supports the ability to specify a list of valid controller ids.
Each of the controllers in the list will receive the ``packet_in'' message only if they
have registered to receive the invalid ttl packets. If controller ids are not specified,
the ``packet_in'' message will be sent only to the controllers having controller id zero
which have registered for the invalid ttl packets.
set_mpls_label:label
Set the label of the outer MPLS label stack entry of a packet. label should be a 20-bit
value that is decimal by default; use a 0x prefix to specify them in hexadecimal.
set_mpls_tc:tc
Set the traffic-class of the outer MPLS label stack entry of a packet. tc should be a in
the range 0 to 7 inclusive.
set_mpls_ttl:ttl
Set the TTL of the outer MPLS label stack entry of a packet. ttl should be in the range 0
to 255 inclusive.
dec_mpls_ttl
Decrement TTL of the outer MPLS label stack entry of a packet. If the TTL is initially
zero or decrementing would make it so, no decrement occurs. Instead, a ``packet-in''
message with reason code OFPR_INVALID_TTL is sent to the main controller (id zero), if it
has enabled receiving them. Processing the current set of actions then stops. However, if
the current set of actions was reached through ``resubmit'' then remaining actions in outer
levels resume processing.
note:[hh]...
Does nothing at all. Any number of bytes represented as hex digits hh may be included.
Pairs of hex digits may be separated by periods for readability. The note action's format
doesn't include an exact length for its payload, so the provided bytes will be padded on
the right by enough bytes with value 0 to make the total number 6 more than a multiple of
8.
move:src[start..end]->dst[start..end]
Copies the named bits from field src to field dst. src and dst must be NXM field names as
defined in nicira-ext.h, e.g. NXM_OF_UDP_SRC or NXM_NX_REG0. Each start and end pair,
which are inclusive, must specify the same number of bits and must fit within its
respective field. Shorthands for [start..end] exist: use [bit] to specify a single bit or
[] to specify an entire field.
Examples: move:NXM_NX_REG0[0..5]->NXM_NX_REG1[26..31] copies the six bits numbered 0
through 5, inclusive, in register 0 into bits 26 through 31, inclusive;
move:NXM_NX_REG0[0..15]->NXM_OF_VLAN_TCI[] copies the least significant 16 bits of register
0 into the VLAN TCI field.
In OpenFlow 1.0 through 1.4, move ordinarily uses an Open vSwitch extension to OpenFlow.
In OpenFlow 1.5, move uses the OpenFlow 1.5 standard copy_field action. The ONF has also
made copy_field available as an extension to OpenFlow 1.3. Open vSwitch 2.4 and later
understands this extension and uses it if a controller uses it, but for backward
compatibility with older versions of Open vSwitch, ovs-ofctl does not use it.
set_field:value[/mask]->dst
load:value->dst[start..end]
Loads a literal value into a field or part of a field. With set_field, value and the
optional mask are given in the customary syntax for field dst, which is expressed as a
field name. For example, set_field:00:11:22:33:44:55->eth_src sets the Ethernet source
address to 00:11:22:33:44:55. With load, value must be an integer value (in decimal or
prefixed by 0x for hexadecimal) and dst is the NXM or OXM name for the field. For example,
load:0x001122334455->OXM_OF_ETH_DST[] has the same effect as the prior set_field example.
The two forms exist for historical reasons. Open vSwitch 1.1 introduced NXAST_REG_LOAD as
a Nicira extension to OpenFlow 1.0 and used load to express it. Later, OpenFlow 1.2
introduced a standard OFPAT_SET_FIELD action that was restricted to loading entire fields,
so Open vSwitch added the form set_field with this restriction. OpenFlow 1.5 extended
OFPAT_SET_FIELD to the point that it became a superset of NXAST_REG_LOAD. Open vSwitch
translates either syntax as necessary for the OpenFlow version in use: in OpenFlow 1.0 and
1.1, NXAST_REG_LOAD; in OpenFlow 1.2, 1.3, and 1.4, NXAST_REG_LOAD for load or for loading
a subfield, OFPAT_SET_FIELD otherwise; and OpenFlow 1.5 and later, OFPAT_SET_FIELD.
push:src[start..end]
Pushes start to end bits inclusive, in fields on top of the stack.
Example: push:NXM_NX_REG2[0..5] push the value stored in register 2 bits 0 through 5,
inclusive, on to the internal stack.
pop:dst[start..end]
Pops from the top of the stack, retrieves the start to end bits inclusive, from the value
popped and store them into the corresponding bits in dst.
Example: pop:NXM_NX_REG2[0..5] pops the value from top of the stack. Set register 2 bits 0
through 5, inclusive, based on bits 0 through 5 from the value just popped.
multipath(fields, basis, algorithm, n_links, arg, dst[start..end])
Hashes fields using basis as a universal hash parameter, then the applies multipath link
selection algorithm (with parameter arg) to choose one of n_links output links numbered 0
through n_links minus 1, and stores the link into dst[start..end], which must be an NXM
field as described above.
fields must be one of the following:
eth_src
Hashes Ethernet source address only.
symmetric_l4
Hashes Ethernet source, destination, and type, VLAN ID, IPv4/IPv6 source,
destination, and protocol, and TCP or SCTP (but not UDP) ports. The hash is
computed so that pairs of corresponding flows in each direction hash to the same
value, in environments where L2 paths are the same in each direction. UDP ports are
not included in the hash to support protocols such as VXLAN that use asymmetric
ports in each direction.
symmetric_l3l4
Hashes IPv4/IPv6 source, destination, and protocol, and TCP or SCTP (but not UDP)
ports. Like symmetric_l4, this is a symmetric hash, but by excluding L2 headers it
is more effective in environments with asymmetric L2 paths (e.g. paths involving
VRRP IP addresses on a router). Not an effective hash function for protocols other
than IPv4 and IPv6, which hash to a constant zero.
symmetric_l3l4+udp
Like symmetric_l3l4+udp, but UDP ports are included in the hash. This is a more
effective hash when asymmetric UDP protocols such as VXLAN are not a consideration.
algorithm must be one of modulo_n, hash_threshold, hrw, and iter_hash. Only the iter_hash
algorithm uses arg.
Refer to nicira-ext.h for more details.
bundle(fields, basis, algorithm, slave_type, slaves:[s1, s2, ...])
Hashes fields using basis as a universal hash parameter, then applies the bundle link
selection algorithm to choose one of the listed slaves represented as slave_type.
Currently the only supported slave_type is ofport. Thus, each s1 through sN should be an
OpenFlow port number. Outputs to the selected slave.
Currently, fields must be either eth_src, symmetric_l4, symmetric_l3l4, or
symmetric_l3l4+udp, and algorithm must be one of hrw and active_backup.
Example: bundle(eth_src,0,hrw,ofport,slaves:4,8) uses an Ethernet source hash with basis 0,
to select between OpenFlow ports 4 and 8 using the Highest Random Weight algorithm.
Refer to nicira-ext.h for more details.
bundle_load(fields, basis, algorithm, slave_type, dst[start..end], slaves:[s1, s2, ...])
Has the same behavior as the bundle action, with one exception. Instead of outputting to
the selected slave, it writes its selection to dst[start..end], which must be an NXM field
as described above.
Example: bundle_load(eth_src, 0, hrw, ofport, NXM_NX_REG0[], slaves:4, 8) uses an Ethernet
source hash with basis 0, to select between OpenFlow ports 4 and 8 using the Highest Random
Weight algorithm, and writes the selection to NXM_NX_REG0[].
Refer to nicira-ext.h for more details.
learn(argument[,argument]...)
This action adds or modifies a flow in an OpenFlow table, similar to ovs-ofctl --strict
mod-flows. The arguments specify the flow's match fields, actions, and other properties,
as follows. At least one match criterion and one action argument should ordinarily be
specified.
idle_timeout=seconds
hard_timeout=seconds
priority=value
cookie=value
send_flow_rem
These arguments have the same meaning as in the usual ovs-ofctl flow syntax.
fin_idle_timeout=seconds
fin_hard_timeout=seconds
Adds a fin_timeout action with the specified arguments to the new flow. This
feature was added in Open vSwitch 1.5.90.
table=number
The table in which the new flow should be inserted. Specify a decimal number
between 0 and 254. The default, if table is unspecified, is table 1.
delete_learned
This flag enables deletion of the learned flows when the flow with the learn action
is removed. Specifically, when the last learn action with this flag and particular
table and cookie values is removed, the switch deletes all of the flows in the
specified table with the specified cookie.
This flag was added in Open vSwitch 2.4.
field=value
field[start..end]=src[start..end]
field[start..end]
Adds a match criterion to the new flow.
The first form specifies that field must match the literal value, e.g.
dl_type=0x0800. All of the fields and values for ovs-ofctl flow syntax are
available with their usual meanings.
The second form specifies that field[start..end] in the new flow must match
src[start..end] taken from the flow currently being processed.
The third form is a shorthand for the second form. It specifies that
field[start..end] in the new flow must match field[start..end] taken from the flow
currently being processed.
load:value->dst[start..end]
load:src[start..end]->dst[start..end]
Adds a load action to the new flow.
The first form loads the literal value into bits start through end, inclusive, in
field dst. Its syntax is the same as the load action described earlier in this
section.
The second form loads src[start..end], a value from the flow currently being
processed, into bits start through end, inclusive, in field dst.
output:field[start..end]
Add an output action to the new flow's actions, that outputs to the OpenFlow port
taken from field[start..end], which must be an NXM field as described above.
For best performance, segregate learned flows into a table (using table=number) that is not
used for any other flows except possibly for a lowest-priority ``catch-all'' flow, that is,
a flow with no match criteria. (This is why the default table is 1, to keep the learned
flows separate from the primary flow table 0.)
clear_actions
Clears all the actions in the action set immediately.
write_actions([action][,action...])
Add the specific actions to the action set. The syntax of actions is the same as in the
actions= field. The action set is carried between flow tables and then executed at the end
of the pipeline.
The actions in the action set are applied in the following order, as required by the
OpenFlow specification, regardless of the order in which they were added to the action set.
Except as specified otherwise below, the action set only holds at most a single action of
each type. When more than one action of a single type is written to the action set, the
one written later replaces the earlier action:
1. strip_vlan
pop_mpls
2. push_mpls
3. push_vlan
4. dec_ttl
dec_mpls_ttl
5. load
move
mod_dl_dst
mod_dl_src
mod_nw_dst
mod_nw_src
mod_nw_tos
mod_nw_ecn
mod_nw_ttl
mod_tp_dst
mod_tp_src
mod_vlan_pcp
mod_vlan_vid
set_field
set_tunnel
set_tunnel64
The action set can contain any number of these actions, with cumulative effect. They
will be applied in the order as added. That is, when multiple actions modify the
same part of a field, the later modification takes effect, and when they modify
different parts of a field (or different fields), then both modifications are
applied.
6. set_queue
7. group
output
resubmit
If more than one of these actions is present, then the one listed earliest above is
executed and the others are ignored, regardless of the order in which they were
added to the action set. (If none of these actions is present, the action set has
no real effect, because the modified packet is not sent anywhere and thus the
modifications are not visible.)
Only the actions listed above may be written to the action set.
write_metadata:value[/mask]
Updates the metadata field for the flow. If mask is omitted, the metadata field is set
exactly to value; if mask is specified, then a 1-bit in mask indicates that the
corresponding bit in the metadata field will be replaced with the corresponding bit from
value. Both value and mask are 64-bit values that are decimal by default; use a 0x prefix
to specify them in hexadecimal.
meter:meter_id
Apply the meter_id before any other actions. If a meter band rate is exceeded, the packet
may be dropped, or modified, depending on the meter band type. See the description of the
Meter Table Commands, above, for more details.
goto_table:table
Indicates the next table in the process pipeline.
fin_timeout(argument[,argument])
This action changes the idle timeout or hard timeout, or both, of this OpenFlow rule when
the rule matches a TCP packet with the FIN or RST flag. When such a packet is observed,
the action reduces the rule's timeouts to those specified on the action. If the rule's
existing timeout is already shorter than the one that the action specifies, then that
timeout is unaffected.
argument takes the following forms:
idle_timeout=seconds
Causes the flow to expire after the given number of seconds of inactivity.
hard_timeout=seconds
Causes the flow to expire after the given number of seconds, regardless of activity.
(seconds specifies time since the flow's creation, not since the receipt of the FIN
or RST.)
This action was added in Open vSwitch 1.5.90.
sample(argument[,argument]...)
Samples packets and sends one sample for every sampled packet.
argument takes the following forms:
probability=packets
The number of sampled packets out of 65535. Must be greater or equal to 1.
collector_set_id=id
The unsigned 32-bit integer identifier of the set of sample collectors to send
sampled packets to. Defaults to 0.
obs_domain_id=id
When sending samples to IPFIX collectors, the unsigned 32-bit integer Observation
Domain ID sent in every IPFIX flow record. Defaults to 0.
obs_point_id=id
When sending samples to IPFIX collectors, the unsigned 32-bit integer Observation
Point ID sent in every IPFIX flow record. Defaults to 0.
Refer to ovs-vswitchd.conf.db(8) for more details on configuring sample collector sets.
This action was added in Open vSwitch 1.10.90.
exit This action causes Open vSwitch to immediately halt execution of further actions. Those
actions which have already been executed are unaffected. Any further actions, including
those which may be in other tables, or different levels of the resubmit call stack, are
ignored. Actions in the action set is still executed (specify clear_actions before exit to
discard them).
conjunction(id, k/n)
An individual OpenFlow flow can match only a single value for each field. However,
situations often arise where one wants to match one of a set of values within a field or
fields. For matching a single field against a set, it is straightforward and efficient to
add multiple flows to the flow table, one for each value in the set. For example, one
might use the following flows to send packets with IP source address a, b, c, or d to the
OpenFlow controller:
ip,ip_src=a actions=controller
ip,ip_src=b actions=controller
ip,ip_src=c actions=controller
ip,ip_src=d actions=controller
Similarly, these flows send packets with IP destination address e, f, g, or h to the
OpenFlow controller:
ip,ip_dst=e actions=controller
ip,ip_dst=f actions=controller
ip,ip_dst=g actions=controller
ip,ip_dst=h actions=controller
Installing all of the above flows in a single flow table yields a disjunctive effect: a
packet is sent to the controller if ip_src ∈ {a,b,c,d} or ip_dst ∈ {e,f,g,h} (or both).
(Pedantically, if both of the above sets of flows are present in the flow table, they
should have different priorities, because OpenFlow says that the results are undefined when
two flows with same priority can both match a single packet.)
Suppose, on the other hand, one wishes to match conjunctively, that is, to send a packet to
the controller only if both ip_src ∈ {a,b,c,d} and ip_dst ∈ {e,f,g,h}. This requires 4 × 4
= 16 flows, one for each possible pairing of ip_src and ip_dst. That is acceptable for our
small example, but it does not gracefully extend to larger sets or greater numbers of
dimensions.
The conjunction action is a solution for conjunctive matches that is built into Open
vSwitch. A conjunction action ties groups of individual OpenFlow flows into higher-level
``conjunctive flows''. Each group corresponds to one dimension, and each flow within the
group matches one possible value for the dimension. A packet that matches one flow from
each group matches the conjunctive flow.
To implement a conjunctive flow with conjunction, assign the conjunctive flow a 32-bit id,
which must be unique within an OpenFlow table. Assign each of the n ≥ 2 dimensions a
unique number from 1 to n; the ordering is unimportant. Add one flow to the OpenFlow flow
table for each possible value of each dimension with conjunction(id, k/n) as the flow's
actions, where k is the number assigned to the flow's dimension. Together, these flows
specify the conjunctive flow's match condition. When the conjunctive match condition is
met, Open vSwitch looks up one more flow that specifies the conjunctive flow's actions and
receives its statistics. This flow is found by setting conj_id to the specified id and
then again searching the flow table.
The following flows provide an example. Whenever the IP source is one of the values in the
flows that match on the IP source (dimension 1 of 2), and the IP destination is one of the
values in the flows that match on IP destination (dimension 2 of 2), Open vSwitch searches
for a flow that matches conj_id against the conjunction ID (1234), finding the first flow
listed below.
conj_id=1234 actions=controller
ip,ip_src=10.0.0.1 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.4 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.6 actions=conjunction(1234, 1/2)
ip,ip_src=10.0.0.7 actions=conjunction(1234, 1/2)
ip,ip_dst=10.0.0.2 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.5 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.7 actions=conjunction(1234, 2/2)
ip,ip_dst=10.0.0.8 actions=conjunction(1234, 2/2)
Many subtleties exist:
• In the example above, every flow in a single dimension has the same form, that is,
dimension 1 matches on ip_src, dimension 2 on ip_dst, but this is not a requirement.
Different flows within a dimension may match on different bits within a field (e.g.
IP network prefixes of different lengths, or TCP/UDP port ranges as bitwise
matches), or even on entirely different fields (e.g. to match packets for TCP source
port 80 or TCP destination port 80).
• The flows within a dimension can vary their matches across more than one field, e.g.
to match only specific pairs of IP source and destination addresses or L4 port
numbers.
• A flow may have multiple conjunction actions, with different id values. This is
useful for multiple conjunctive flows with overlapping sets. If one conjunctive
flow matches packets with both ip_src ∈ {a,b} and ip_dst ∈ {d,e} and a second
conjunctive flow matches ip_src ∈ {b,c} and ip_dst ∈ {f,g}, for example, then the
flow that matches ip_src=b would have two conjunction actions, one for each
conjunctive flow. The order of conjunction actions within a list of actions is not
significant.
• A flow with conjunction actions may also include note actions for annotations, but
not any other kind of actions. (They would not be useful because they would never
be executed.)
• All of the flows that constitute a conjunctive flow with a given id must have the
same priority. (Flows with the same id but different priorities are currently
treated as different conjunctive flows, that is, currently id values need only be
unique within an OpenFlow table at a given priority. This behavior isn't guaranteed
to stay the same in later releases, so please use id values unique within an
OpenFlow table.)
• Conjunctive flows must not overlap with each other, at a given priority, that is,
any given packet must be able to match at most one conjunctive flow at a given
priority. Overlapping conjunctive flows yield unpredictable results.
• Following a conjunctive flow match, the search for the flow with conj_id=id is done
in the same general-purpose way as other flow table searches, so one can use flows
with conj_id=id to act differently depending on circumstances. (One exception is
that the search for the conj_id=id flow itself ignores conjunctive flows, to avoid
recursion.) If the search with conj_id=id fails, Open vSwitch acts as if the
conjunctive flow had not matched at all, and continues searching the flow table for
other matching flows.
• OpenFlow prerequisite checking occurs for the flow with conj_id=id in the same way
as any other flow, e.g. in an OpenFlow 1.1+ context, putting a mod_nw_src action
into the example above would require adding an ip match, like this:
conj_id=1234,ip actions=mod_nw_src:1.2.3.4,controller
• OpenFlow prerequisite checking also occurs for the individual flows that comprise a
conjunctive match in the same way as any other flow.
• The flows that constitute a conjunctive flow do not have useful statistics. They
are never updated with byte or packet counts, and so on. (For such a flow,
therefore, the idle and hard timeouts work much the same way.)
• Conjunctive flows can be a useful building block for negation, that is, inequality
matches like tcp_src ≠ 80. To implement an inequality match, convert it to a pair
of range matches, e.g. 0 ≤ tcp_src < 80 and 80 < tcp_src ≤ 65535, then convert each
of the range matches into a collection of bitwise matches as explained above in the
description of tcp_src.
• Sometimes there is a choice of which flows include a particular match. For example,
suppose that we added an extra constraint to our example, to match on ip_src ∈
{a,b,c,d} and ip_dst ∈ {e,f,g,h} and tcp_dst = i. One way to implement this is to
add the new constraint to the conj_id flow, like this:
conj_id=1234,tcp,tcp_dst=i actions=mod_nw_src:1.2.3.4,controller
but this is not recommended because of the cost of the extra flow table lookup.
Instead, add the constraint to the individual flows, either in one of the dimensions
or (slightly better) all of them.
• A conjunctive match must have n ≥ 2 dimensions (otherwise a conjunctive match is not
necessary). Open vSwitch enforces this.
• Each dimension within a conjunctive match should ordinarily have more than one flow.
Open vSwitch does not enforce this.
The conjunction action and conj_id field were introduced in Open vSwitch 2.4.
An opaque identifier called a cookie can be used as a handle to identify a set of flows:
cookie=value
A cookie can be associated with a flow using the add-flow, add-flows, and mod-flows commands.
value can be any 64-bit number and need not be unique among flows. If this field is omitted, a
default cookie value of 0 is used.
cookie=value/mask
When using NXM, the cookie can be used as a handle for querying, modifying, and deleting flows.
value and mask may be supplied for the del-flows, mod-flows, dump-flows, and dump-aggregate
commands to limit matching cookies. A 1-bit in mask indicates that the corresponding bit in
cookie must match exactly, and a 0-bit wildcards that bit. A mask of -1 may be used to exactly
match a cookie.
The mod-flows command can update the cookies of flows that match a cookie by specifying the cookie
field twice (once with a mask for matching and once without to indicate the new value):
ovs-ofctl mod-flows br0 cookie=1,actions=normal
Change all flows' cookies to 1 and change their actions to normal.
ovs-ofctl mod-flows br0 cookie=1/-1,cookie=2,actions=normal
Update cookies with a value of 1 to 2 and change their actions to normal.
The ability to match on cookies was added in Open vSwitch 1.5.0.
The following additional field sets the priority for flows added by the add-flow and add-flows commands.
For mod-flows and del-flows when --strict is specified, priority must match along with the rest of the
flow specification. For mod-flows without --strict, priority is only significant if the command creates
a new flow, that is, non-strict mod-flows does not match on priority and will not change the priority of
existing flows. Other commands do not allow priority to be specified.
priority=value
The priority at which a wildcarded entry will match in comparison to others. value is a number
between 0 and 65535, inclusive. A higher value will match before a lower one. An exact-match
entry will always have priority over an entry containing wildcards, so it has an implicit priority
value of 65535. When adding a flow, if the field is not specified, the flow's priority will
default to 32768.
OpenFlow leaves behavior undefined when two or more flows with the same priority can match a
single packet. Some users expect ``sensible'' behavior, such as more specific flows taking
precedence over less specific flows, but OpenFlow does not specify this and Open vSwitch does not
implement it. Users should therefore take care to use priorities to ensure the behavior that they
expect.
The add-flow, add-flows, and mod-flows commands support the following additional options. These options
affect only new flows. Thus, for add-flow and add-flows, these options are always significant, but for
mod-flows they are significant only if the command creates a new flow, that is, their values do not
update or affect existing flows.
idle_timeout=seconds
Causes the flow to expire after the given number of seconds of inactivity. A value of 0 (the
default) prevents a flow from expiring due to inactivity.
hard_timeout=seconds
Causes the flow to expire after the given number of seconds, regardless of activity. A value of 0
(the default) gives the flow no hard expiration deadline.
importance=value
Sets the importance of a flow. The flow entry eviction mechanism can use importance as a factor
in deciding which flow to evict. A value of 0 (the default) makes the flow non-evictable on the
basis of importance. Specify a value between 0 and 65535.
Only OpenFlow 1.4 and later support importance.
send_flow_rem
Marks the flow with a flag that causes the switch to generate a ``flow removed'' message and send
it to interested controllers when the flow later expires or is removed.
check_overlap
Forces the switch to check that the flow match does not overlap that of any different flow with
the same priority in the same table. (This check is expensive so it is best to avoid it.)
The dump-flows, dump-aggregate, del-flow and del-flows commands support these additional optional fields:
out_port=port
If set, a matching flow must include an output action to port, which must be an OpenFlow port
number or name (e.g. local).
out_group=port
If set, a matching flow must include an group action naming group, which must be an OpenFlow group
number. This field is supported in Open vSwitch 2.5 and later and requires OpenFlow 1.1 or later.
Table Entry Output
The dump-tables and dump-aggregate commands print information about the entries in a datapath's tables.
Each line of output is a flow entry as described in Flow Syntax, above, plus some additional fields:
duration=secs
The time, in seconds, that the entry has been in the table. secs includes as much precision as
the switch provides, possibly to nanosecond resolution.
n_packets
The number of packets that have matched the entry.
n_bytes
The total number of bytes from packets that have matched the entry.
The following additional fields are included only if the switch is Open vSwitch 1.6 or later and the NXM
flow format is used to dump the flow (see the description of the --flow-format option below). The values
of these additional fields are approximations only and in particular idle_age will sometimes become
nonzero even for busy flows.
hard_age=secs
The integer number of seconds since the flow was added or modified. hard_age is displayed only if
it differs from the integer part of duration. (This is separate from duration because mod-flows
restarts the hard_timeout timer without zeroing duration.)
idle_age=secs
The integer number of seconds that have passed without any packets passing through the flow.
Group Syntax
Some ovs-ofctl commands accept an argument that describes a group or groups. Such flow descriptions
comprise a series field=value assignments, separated by commas or white space. (Embedding spaces into a
group description normally requires quoting to prevent the shell from breaking the description into
multiple arguments.). Unless noted otherwise only the last instance of each field is honoured.
group_id=id
The integer group id of group. When this field is specified in del-groups or dump-groups, the
keyword "all" may be used to designate all groups. This field is required.
type=type
The type of the group. The add-group, add-groups and mod-groups commands require this field. It
is prohibited for other commands. The following keywords designated the allowed types:
all Execute all buckets in the group.
select Execute one bucket in the group. The switch should select the bucket in such a way that
should implement equal load sharing is achieved. The switch may optionally select the
bucket based on bucket weights.
indirect
Executes the one bucket in the group.
ff
fast_failover
Executes the first live bucket in the group which is associated with a live port or group.
command_bucket_id=id
The bucket to operate on. The insert-buckets and remove-buckets commands require this field. It
is prohibited for other commands. id may be an integer or one of the following keywords:
all Operate on all buckets in the group. Only valid when used with the remove-buckets command
in which case the effect is to remove all buckets from the group.
first Operate on the first bucket present in the group. In the case of the insert-buckets
command the effect is to insert new bucets just before the first bucket already present in
the group; or to replace the buckets of the group if there are no buckets already present
in the group. In the case of the remove-buckets command the effect is to remove the first
bucket of the group; or do nothing if there are no buckets present in the group.
last Operate on the last bucket present in the group. In the case of the insert-buckets command
the effect is to insert new bucets just after the last bucket already present in the group;
or to replace the buckets of the group if there are no buckets already present in the
group. In the case of the remove-buckets command the effect is to remove the last bucket
of the group; or do nothing if there are no buckets present in the group.
If id is an integer then it should correspond to the bucket_id of a bucket present in the group.
In case of the insert-buckets command the effect is to insert buckets just before the bucket in
the group whose bucket_id is id. In case of the iremove-buckets command the effect is to remove
the in the group whose bucket_id is id. It is an error if there is no bucket persent group in
whose bucket_id is id.
selection_method=method
The selection method used to select a bucket for a select group. This is a string of 1 to 15
bytes in length known to lower layers. This field is optional for add-group, add-groups and
mod-group commands on groups of type select. Prohibited otherwise. The default value is the empty
string.
Other than the empty string, hash is currently the only defined selection method.
This option will use a Netronome OpenFlow extension which is only supported when using Open
vSwitch 2.4 and later with OpenFlow 1.5 and later.
selection_method_param=param
64-bit integer parameter to the selection method selected by the selection_method field. The
parameter's use is defined by the lower-layer that implements the selection_method. It is
optional if the selection_method field is specified as a non-empty string. Prohibited otherwise.
The default value is zero.
This option will use a Netronome OpenFlow extension which is only supported when using Open
vSwitch 2.4 and later with OpenFlow 1.5 and later.
fields=field
fields(field[=mask]...)
The field parameters to selection method selected by the selection_method field. The syntax is
described in Flow Syntax with the additional restrictions that if a value is provided it is
treated as a wildcard mask and wildcard masks following a slash are prohibited. The pre-requisites
of fields must be provided by any flows that output to the group. The use of the fields is defined
by the lower-layer that implements the selection_method. They are optional if the
selection_method field is specified as a non-empty string. Prohibited otherwise. The default is
no fields.
This option will use a Netronome OpenFlow extension which is only supported when using Open
vSwitch 2.4 and later with OpenFlow 1.5 and later.
bucket=bucket_parameters
The add-group, add-groups and mod-group commands require at least one bucket field. Bucket fields
must appear after all other fields. Multiple bucket fields to specify multiple buckets. The
order in which buckets are specified corresponds to their order in the group. If the type of the
group is "indirect" then only one group may be specified. bucket_parameters consists of a list of
field=value assignments, separated by commas or white space followed by a comma-separated list of
actions. The fields for bucket_parameters are:
bucket_id=id
The 32-bit integer group id of the bucket. Values greater than 0xffffff00 are reserved.
This field was added in Open vSwitch 2.4 to conform with the OpenFlow 1.5 specification. It
is not supported when earlier versions of OpenFlow are used. Open vSwitch will
automatically allocate bucket ids when they are not specified.
actions=[action][,action...]
The syntax of actions are identical to the actions= field described in Flow Syntax above.
Specyfing actions= is optional, any unknown bucket parameter will be interpreted as an
action.
weight=value
The relative weight of the bucket as an integer. This may be used by the switch during
bucket select for groups whose type is select.
watch_port=port
Port used to determine liveness of group. This or the watch_group field is required for
groups whose type is ff or fast_failover.
watch_group=group_id
Group identifier of group used to determine liveness of group. This or the watch_port
field is required for groups whose type is ff or fast_failover.
Meter Syntax
The meter table commands accept an argument that describes a meter. Such meter descriptions comprise a
series field=value assignments, separated by commas or white space. (Embedding spaces into a group
description normally requires quoting to prevent the shell from breaking the description into multiple
arguments.). Unless noted otherwise only the last instance of each field is honoured.
meter=id
The integer meter id of the meter. When this field is specified in del-meter, dump-meter, or
meter-stats, the keyword "all" may be used to designate all meters. This field is required, exept
for meter-stats, which dumps all stats when this field is not specified.
kbps
pktps The unit for the meter band rate parameters, either kilobits per second, or packets per second,
respectively. One of these must be specified. The burst size unit corresponds to the rate unit
by dropping the "per second", i.e., burst is in units of kilobits or packets, respectively.
burst Specify burst size for all bands, or none of them, if this flag is not given.
stats Collect meter and band statistics.
bands=band_parameters
The add-meter and mod-meter commands require at least one band specification. Bands must appear
after all other fields.
type=type
The type of the meter band. This keyword starts a new band specification. Each band
specifies a rate above which the band is to take some action. The action depends on the
band type. If multiple bands' rate is exceeded, then the band with the highest rate among
the exceeded bands is selected. The following keywords designate the allowed meter band
types:
drop Drop packets exceeding the band's rate limit.
The other band_parameters are:
rate=value
The relative rate limit for this band, in kilobits per second or packets per second,
depending on the meter flags defined above.
burst_size=size
The maximum burst allowed for the band. If pktps is specified, then size is a packet
count, otherwise it is in kilobits. If unspecified, the switch is free to select some
reasonable value depending on its configuration.
OPTIONS
--strict
Uses strict matching when running flow modification commands.
--bundle
Execute flow mods as an OpenFlow 1.4 atomic bundle transaction.
• Within a bundle, all flow mods are processed in the order they appear and as a single
atomic transaction, meaning that if one of them fails, the whole transaction fails and none
of the changes are made to the switch's flow table, and that each given datapath packet
traversing the OpenFlow tables sees the flow tables either as before the transaction, or
after all the flow mods in the bundle have been successfully applied.
• The beginning and the end of the flow table modification commands in a bundle are delimited
with OpenFlow 1.4 bundle control messages, which makes it possible to stream the included
commands without explicit OpenFlow barriers, which are otherwise used after each flow table
modification command. This may make large modifications execute faster as a bundle.
• Bundles require OpenFlow 1.4 or higher. An explicit -O OpenFlow14 option is not needed,
but you may need to enable OpenFlow 1.4 support for OVS by setting the OVSDB protocols
column in the bridge table.
-O [version[,version]...]
--protocols=[version[,version]...]
Sets the OpenFlow protocol versions that are allowed when establishing an OpenFlow session.
The following versions are considered to be ready for general use. These protocol versions are
enabled by default:
• OpenFlow10, for OpenFlow 1.0.
Support for the following protocol versions is provided for testing and development purposes.
They are not enabled by default:
• OpenFlow11, for OpenFlow 1.1.
• OpenFlow12, for OpenFlow 1.2.
• OpenFlow13, for OpenFlow 1.3.
-F format[,format...]
--flow-format=format[,format...]
ovs-ofctl supports the following individual flow formats, any number of which may be listed as
format:
OpenFlow10-table_id
This is the standard OpenFlow 1.0 flow format. All OpenFlow switches and all versions of
Open vSwitch support this flow format.
OpenFlow10+table_id
This is the standard OpenFlow 1.0 flow format plus a Nicira extension that allows ovs-ofctl
to specify the flow table in which a particular flow should be placed. Open vSwitch 1.2
and later supports this flow format.
NXM-table_id (Nicira Extended Match)
This Nicira extension to OpenFlow is flexible and extensible. It supports all of the
Nicira flow extensions, such as tun_id and registers. Open vSwitch 1.1 and later supports
this flow format.
NXM+table_id (Nicira Extended Match)
This combines Nicira Extended match with the ability to place a flow in a specific table.
Open vSwitch 1.2 and later supports this flow format.
OXM-OpenFlow12
OXM-OpenFlow13
OXM-OpenFlow14
These are the standard OXM (OpenFlow Extensible Match) flow format in OpenFlow 1.2, 1.3,
and 1.4, respectively.
ovs-ofctl also supports the following abbreviations for collections of flow formats:
any Any supported flow format.
OpenFlow10
OpenFlow10-table_id or OpenFlow10+table_id.
NXM NXM-table_id or NXM+table_id.
OXM OXM-OpenFlow12, OXM-OpenFlow13, or OXM-OpenFlow14.
For commands that modify the flow table, ovs-ofctl by default negotiates the most widely supported
flow format that supports the flows being added. For commands that query the flow table,
ovs-ofctl by default uses the most advanced format supported by the switch.
This option, where format is a comma-separated list of one or more of the formats listed above,
limits ovs-ofctl's choice of flow format. If a command cannot work as requested using one of the
specified flow formats, ovs-ofctl will report a fatal error.
-P format
--packet-in-format=format
ovs-ofctl supports the following packet_in formats, in order of increasing capability:
openflow10
This is the standard OpenFlow 1.0 packet in format. It should be supported by all OpenFlow
switches.
nxm (Nicira Extended Match)
This packet_in format includes flow metadata encoded using the NXM format.
Usually, ovs-ofctl prefers the nxm packet_in format, but will allow the switch to choose its
default if nxm is unsupported. When format is one of the formats listed in the above table,
ovs-ofctl will insist on the selected format. If the switch does not support the requested
format, ovs-ofctl will report a fatal error. This option only affects the monitor command.
--timestamp
Print a timestamp before each received packet. This option only affects the monitor, snoop, and
ofp-parse-pcap commands.
-m
--more Increases the verbosity of OpenFlow messages printed and logged by ovs-ofctl commands. Specify
this option more than once to increase verbosity further.
--sort[=field]
--rsort[=field]
Display output sorted by flow field in ascending (--sort) or descending (--rsort) order, where
field is any of the fields that are allowed for matching or priority to sort by priority. When
field is omitted, the output is sorted by priority. Specify these options multiple times to sort
by multiple fields.
Any given flow will not necessarily specify a value for a given field. This requires special
treatement:
• A flow that does not specify any part of a field that is used for sorting is sorted after
all the flows that do specify the field. For example, --sort=tcp_src will sort all the
flows that specify a TCP source port in ascending order, followed by the flows that do not
specify a TCP source port at all.
• A flow that only specifies some bits in a field is sorted as if the wildcarded bits were
zero. For example, --sort=nw_src would sort a flow that specifies nw_src=192.168.0.0/24
the same as nw_src=192.168.0.0.
These options currently affect only dump-flows output. The following options are valid on POSIX
based platforms.
--pidfile[=pidfile]
Causes a file (by default, ovs-ofctl.pid) to be created indicating the PID of the running process.
If the pidfile argument is not specified, or if it does not begin with /, then it is created in
/var/run/openvswitch.
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified pidfile already exists and is locked by
a running process, ovs-ofctl refuses to start. Specify --overwrite-pidfile to cause it to instead
overwrite the pidfile.
When --pidfile is not specified, this option has no effect.
--detach
Runs ovs-ofctl as a background process. The process forks, and in the child it starts a new
session, closes the standard file descriptors (which has the side effect of disabling logging to
the console), and changes its current directory to the root (unless --no-chdir is specified).
After the child completes its initialization, the parent exits. ovs-ofctl detaches only when
executing the monitor or snoop commands.
--monitor
Creates an additional process to monitor the ovs-ofctl daemon. If the daemon dies due to a signal
that indicates a programming error (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIGPIPE, SIGSEGV,
SIGXCPU, or SIGXFSZ) then the monitor process starts a new copy of it. If the daemon dies or
exits for another reason, the monitor process exits.
This option is normally used with --detach, but it also functions without it.
--no-chdir
By default, when --detach is specified, ovs-ofctl changes its current working directory to the
root directory after it detaches. Otherwise, invoking ovs-ofctl from a carelessly chosen
directory would prevent the administrator from unmounting the file system that holds that
directory.
Specifying --no-chdir suppresses this behavior, preventing ovs-ofctl from changing its current
working directory. This may be useful for collecting core files, since it is common behavior to
write core dumps into the current working directory and the root directory is not a good directory
to use.
This option has no effect when --detach is not specified.
--user Causes ovs-ofctl to run as a different user specified in "user:group", thus dropping most of the
root privileges. Short forms "user" and ":group" are also allowed, with current user or group are
assumed respectively. Only daemons started by the root user accepts this argument.
On Linux, daemons will be granted CAP_IPC_LOCK and CAP_NET_BIND_SERVICES before dropping root
privileges. Daemons interact with datapath, such as ovs-vswitchd, will be granted two additional
capabilities, namely CAP_NET_ADMIN and CAP_NET_RAW. The capability change will apply even if new
user is "root".
On Windows, this option is not currently supported. For security reasons, specifying this option
will cause the daemon process not to start.
--unixctl=socket
Sets the name of the control socket on which ovs-ofctl listens for runtime management commands
(see RUNTIME MANAGEMENT COMMANDS, below). If socket does not begin with /, it is interpreted as
relative to /var/run/openvswitch. If --unixctl is not used at all, the default socket is
/var/run/openvswitch/ovs-ofctl.pid.ctl, where pid is ovs-ofctl's process ID.
On Windows, uses a kernel chosen TCP port on the localhost to listen for runtime management
commands. The kernel chosen TCP port value is written in a file whose absolute path is pointed by
socket. If --unixctl is not used at all, the file is created as ovs-ofctl.ctl in the configured
OVS_RUNDIR directory.
Specifying none for socket disables the control socket feature.
Public Key Infrastructure Options
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as ovs-ofctl's identity for outgoing SSL
connections.
-c cert.pem
--certificate=cert.pem
Specifies a PEM file containing a certificate that certifies the private key specified on -p or
--private-key to be trustworthy. The certificate must be signed by the certificate authority (CA)
that the peer in SSL connections will use to verify it.
-C cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate that ovs-ofctl should use to verify
certificates presented to it by SSL peers. (This may be the same certificate that SSL peers use
to verify the certificate specified on -c or --certificate, or it may be a different one,
depending on the PKI design in use.)
-C none
--ca-cert=none
Disables verification of certificates presented by SSL peers. This introduces a security risk,
because it means that certificates cannot be verified to be those of known trusted hosts.
-v[spec]
--verbose=[spec]
Sets logging levels. Without any spec, sets the log level for every module and destination to
dbg. Otherwise, spec is a list of words separated by spaces or commas or colons, up to one from
each category below:
• A valid module name, as displayed by the vlog/list command on ovs-appctl(8), limits the log
level change to the specified module.
• syslog, console, or file, to limit the log level change to only to the system log, to the
console, or to a file, respectively. (If --detach is specified, ovs-ofctl closes its
standard file descriptors, so logging to the console will have no effect.)
On Windows platform, syslog is accepted as a word and is only useful along with the
--syslog-target option (the word has no effect otherwise).
• off, emer, err, warn, info, or dbg, to control the log level. Messages of the given
severity or higher will be logged, and messages of lower severity will be filtered out.
off filters out all messages. See ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a file will not take place unless --log-file
is also specified (see below).
For compatibility with older versions of OVS, any is accepted as a word but has no effect.
-v
--verbose
Sets the maximum logging verbosity level, equivalent to --verbose=dbg.
-vPATTERN:destination:pattern
--verbose=PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to ovs-appctl(8) for a description of the
valid syntax for pattern.
-vFACILITY:facility
--verbose=FACILITY:facility
Sets the RFC5424 facility of the log message. facility can be one of kern, user, mail, daemon,
auth, syslog, lpr, news, uucp, clock, ftp, ntp, audit, alert, clock2, local0, local1, local2,
local3, local4, local5, local6 or local7. If this option is not specified, daemon is used as the
default for the local system syslog and local0 is used while sending a message to the target
provided via the --syslog-target option.
--log-file[=file]
Enables logging to a file. If file is specified, then it is used as the exact name for the log
file. The default log file name used if file is omitted is /var/log/openvswitch/ovs-ofctl.log.
--syslog-target=host:port
Send syslog messages to UDP port on host, in addition to the system syslog. The host must be a
numerical IP address, not a hostname.
--syslog-method=method
Specify method how syslog messages should be sent to syslog daemon. Following forms are
supported:
• libc, use libc syslog() function. This is the default behavior. Downside of using this
options is that libc adds fixed prefix to every message before it is actually sent to the
syslog daemon over /dev/log UNIX domain socket.
• unix:file, use UNIX domain socket directly. It is possible to specify arbitrary message
format with this option. However, rsyslogd 8.9 and older versions use hard coded parser
function anyway that limits UNIX domain socket use. If you want to use arbitrary message
format with older rsyslogd versions, then use UDP socket to localhost IP address instead.
• udp:ip:port, use UDP socket. With this method it is possible to use arbitrary message
format also with older rsyslogd. When sending syslog messages over UDP socket extra
precaution needs to be taken into account, for example, syslog daemon needs to be
configured to listen on the specified UDP port, accidental iptables rules could be
interfering with local syslog traffic and there are some security considerations that apply
to UDP sockets, but do not apply to UNIX domain sockets.
-h
--help Prints a brief help message to the console.
-V
--version
Prints version information to the console.
RUNTIME MANAGEMENT COMMANDS
ovs-appctl(8) can send commands to a running ovs-ofctl process. The supported commands are listed below.
exit Causes ovs-ofctl to gracefully terminate. This command applies only when executing the monitor or
snoop commands.
ofctl/set-output-file file
Causes all subsequent output to go to file instead of stderr. This command applies only when
executing the monitor or snoop commands.
ofctl/send ofmsg...
Sends each ofmsg, specified as a sequence of hex digits that express an OpenFlow message, on the
OpenFlow connection. This command is useful only when executing the monitor command.
ofctl/barrier
Sends an OpenFlow barrier request on the OpenFlow connection and waits for a reply. This command
is useful only for the monitor command.
EXAMPLES
The following examples assume that ovs-vswitchd has a bridge named br0 configured.
ovs-ofctl dump-tables br0
Prints out the switch's table stats. (This is more interesting after some traffic has passed
through.)
ovs-ofctl dump-flows br0
Prints the flow entries in the switch.
SEE ALSO
ovs-appctl(8), ovs-vswitchd(8) ovs-vswitchd.conf.db(8)