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ovs-ofctl(8) |
Open vSwitch Manual |
ovs-ofctl(8) |
ovs-ofctl - administer OpenFlow switches
ovs-ofctl [ options] command [ switch]
[ args...]
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.
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:host[:port]
-
- tcp:host[:port]
- The specified port on the given host, which can be expressed
either as a DNS name (if built with unbound library) or an IP address in
IPv4 or IPv6 address format. Wrap IPv6 addresses in square brackets, e.g.
tcp:[::1]:6653. On Linux, use %device to designate a
scope for IPv6 link-level addresses, e.g.
tcp:[fe80::1234%eth0]: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, connect to a local named pipe that is represented by a file
created in the path file to mimic the behavior of a Unix domain
socket.
- 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 setting
- This command configures flow table settings in switch for OpenFlow
table table, which may be expressed as a number or (unless
--no-names is specified) a name.
- 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 (unless --no-names is
specified) 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 ip link
set up or ip link set 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.
Use --sort and --rsort to control display order. The
--names/ --no-names and --stats/--no-stats
options also affect output formatting. See the descriptions of these
options, under OPTIONS below, for more information
- 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.
- queue-get-config switch [port [queue]]
- Prints to the console the configuration of queue on port in
switch. If port is omitted or ANY, reports queues for
all port. If queue is omitted or ANY, reports all queues.
For OpenFlow 1.3 and earlier, the output always includes all queues,
ignoring queue if specified.
- This command has limited usefulness, because ports often have no
configured queues and because the OpenFlow protocol provides only very
limited information about the configuration of a queue.
- dump-ipfix-bridge switch
- Prints to the console the statistics of bridge IPFIX for switch. If
bridge IPFIX is configured on the switch, IPFIX statistics can be
retrieved. Otherwise, error message will be printed.
- This command uses an Open vSwitch extension that is only in Open vSwitch
2.6 and later.
- dump-ipfix-flow switch
- Prints to the console the statistics of flow-based IPFIX for
switch. If flow-based IPFIX is configured on the switch,
statistics of all the collector set ids on the switch will be
printed. Otherwise, print error message.
- Refer to ovs-vswitchd.conf.db(5) for more details on configuring
flow based IPFIX and collector set ids.
- This command uses an Open vSwitch extension that is only in Open vSwitch
2.6 and later.
- ct-flush-zone switch zone
- Flushes the connection tracking entries in zone on
switch.
- This command uses an Open vSwitch extension that is only in Open vSwitch
2.6 and later.
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. In OpenFlow 1.0 and 1.1, re-adding a flow always resets the
flow's packet and byte counters to 0, and in OpenFlow 1.2 and later, it
does so only if the reset_counts flag is set.
- 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 packet-out
- Connects to switch and instructs it to execute the
packet-out OpenFlow message, specified as defined in Packet-Out
Syntax section.
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, and the optional --bundle
option operates the command as a single atomic transation, see option
--bundle, below.
The group commands work only with switches that support OpenFlow 1.1 or later or
the Open vSwitch group extensions to OpenFlow 1.0 (added in Open vSwitch
2.9.90). For OpenFlow 1.1 or later, it is necessary to explicitly enable these
protocol versions in ovs-ofctl (using -O). For more information,
see ``Q: What versions of OpenFlow does Open vSwitch support?'' in the Open
vSwitch FAQ.
- [--bundle] add-group switch group
-
- [--bundle] add-group switch - <
file
-
- [--bundle] add-groups switch file
- Add each group entry to switch's tables. Each group specification
(e.g., each line in file) may start with add, modify,
add_or_mod, delete, insert_bucket, or
remove_bucket keyword to specify whether a flow is to be added,
modified, or deleted, or whether a group bucket is to be added or removed.
For backwards compatibility a group specification without one of these
keywords is treated as a group add. All group mods are executed in the
order specified.
- [--bundle] [--may-create] mod-group switch
group
-
- [--bundle] [--may-create] mod-group switch
- < file
- Modify the action buckets in entries from switch's tables for each
group entry. If a specified group does not already exist, then without
--may-create, this command has no effect; with --may-create,
it creates a new group. The --may-create option uses an Open
vSwitch extension to OpenFlow only implemented in Open vSwitch 2.6 and
later.
- [--bundle] del-groups switch
-
- [--bundle] del-groups switch [group]
-
- [--bundle] 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.
- [--bundle] insert-buckets switch group
-
- [--bundle] 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.
- [--bundle] remove-buckets switch group
-
- [--bundle] 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.
- 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.
- 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 [group]
- Prints to the console statistics for the specified group in
switch's tables. If group is omitted then statistics for all
groups are printed.
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. 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.
- 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 [meter]
- Delete entries from switch's meter table. To delete only a specific
meter, specify its number as meter. Otherwise, if meter is
omitted, or if it is specified as all, then all meters are
deleted.
- dump-meters switch [meter]
- Print entries from switch's meter table. To print only a specific
meter, specify its number as meter. Otherwise, if meter is
omitted, or if it is specified as all, then all meters are
printed.
- 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.
Transactional updates to both flow and group tables can be made with the
bundle command. file is a text file that contains zero or more
flow mods, group mods, or packet-outs in Flow Syntax, Group
Syntax, or Packet-Out Syntax, each line preceded by flow,
group, or packet-out keyword, correspondingly. The flow
keyword may be optionally followed by one of the keywords add,
modify, modify_strict, delete, or delete_strict,
of which the add is assumed if a bare flow is given. Similarly,
the group keyword may be optionally followed by one of the keywords
add, modify, add_or_mod, delete,
insert_bucket, or remove_bucket, of which the add is
assumed if a bare group is given.
- bundle switch file
- Execute all flow and group mods in file as a single atomic
transaction against switch's tables. All bundled mods are executed
in the order specified.
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.
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.
- 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. Only OpenFlow 1.1 and 1.2 support invalid_ttl; Open vSwitch
also implements it for OpenFlow 1.0 as an extension.
- 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=table
- Limits the monitoring to the table with the given table, which may
be expressed as a number between 0 and 254 or (unless --no-names is
specified) a name. 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.
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.
- 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.
Some ovs-ofctl commands accept an argument that describes a flow or
flows. Such flow descriptions comprise a series of
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.
ovs-fields(7) describes the supported fields and how to match them. In
addition to match fields, commands that operate on flows accept a few
additional key-value pairs:
- table=table
- For flow dump commands, limits the flows dumped to those in table,
which may be expressed as a number between 0 and 255 or (unless
--no-names is specified) a name. If not specified (or if 255 is
specified as table), 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.
- duration=...
-
- n_packet=...
-
- n_bytes=...
- ovs-ofctl ignores assignments to these ``fields'' 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
may be an NXM field name, as described above, or a match field name.
output: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.
- output(port=port,max_len=nbytes)
- Outputs the packet to the OpenFlow port number read from port, with
maximum packet size set to nbytes. port may be OpenFlow port
number, local, or in_port. Patch port is not supported.
Packets larger than nbytes will be trimmed to nbytes while
packets smaller than nbytes remains the original size.
- group:group_id
- Outputs the packet to the OpenFlow group group_id. OpenFlow 1.1
introduced support for groups; Open vSwitch 2.6 and later also supports
output to groups as an extension to OpenFlow 1.0. 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 and its metadata 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.
- userdata=hh...
- Supplies the bytes represented as hex digits hh as additional data
to the controller in the packet-in message. Pairs of hex digits may be
separated by periods for readability.
- pause
- Causes the switch to freeze the packet's trip through Open vSwitch flow
tables and serializes that state into the packet-in message as a
``continuation,'' an additional property in the NXT_PACKET_IN2
message. The controller can later send the continuation back to the switch
in an NXT_RESUME message, which will restart the packet's traversal
from the point where it was interrupted. This permits an OpenFlow
controller to interpose on a packet midway through processing in Open
vSwitch.
- meter_id=id
- Use meter id to rate-limit the OpenFlow packet-in messages that
this action sends to the controller. By default, packets sent to the
controller are associated with the "controller" virtual meter,
if one was configured.
- If any reason other than action or any nonzero
controller-id is supplied, Open vSwitch extension
NXAST_CONTROLLER, supported by Open vSwitch 1.6 and later, is used.
If userdata is supplied, then NXAST_CONTROLLER2, supported
by Open vSwitch 2.6 and later, is used.
- 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])
-
- resubmit([port],[table],ct)
- Re-searches this OpenFlow flow table (or table table, if specified)
with the in_port field replaced by port (if port is
specified) and the packet 5-tuple fields swapped with the corresponding
conntrack original direction tuple fields (if ct is specified, see
ct_nw_src above), and executes the actions found, if any, in
addition to any other actions in this flow entry. The in_port and
swapped 5-tuple fields are restored immediately after the search, before
any actions are executed.
- The table may be expressed as a number between 0 and 254 or (unless
--no-names is specified) a name.
- The ct option requires a valid connection tracking state as a match
prerequisite in the flow where this action is placed. Examples of valid
connection tracking state matches include ct_state=+new,
ct_state=+est, ct_state=+rel, and
ct_state=+trk-inv.
- Recursive resubmit actions are obeyed up to implementation-defined
limits:
- •
- Open vSwitch 1.0.1 and earlier did not support recursion.
- •
- Open vSwitch 1.0.2 and 1.0.3 limited recursion to 8 levels.
- •
- Open vSwitch 1.1 and 1.2 limited recursion to 16 levels.
- •
- Open vSwitch 1.2 through 1.8 limited recursion to 32 levels.
- •
- Open vSwitch 1.9 through 2.0 limited recursion to 64 levels.
- •
- Open vSwitch 2.1 through 2.5 limited recursion to 64 levels and impose a
total limit of 4,096 resubmits per flow translation (earlier versions did
not impose any total limit).
- •
- Open vSwitch 2.6 and later imposes the same limits as 2.5, with one
exception: resubmit from table x to any table y >
x does not count against the recursion limit.
- Open vSwitch before 1.2.90 did not support table. Open vSwitch
before 2.7 did not support ct.
- 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. A ct action always sets the packet to an untracked state
and clears out the ct_state fields for the current processing path.
Those fields are only available for the processing path pointed to by the
table argument. 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.
- force
A committed connection always has the directionality of
the packet that caused the connection to be committed in the first place. This
is the ``original direction'' of the connection, and the opposite direction is
the ``reply direction''. If a connection is already committed, but it is in
the wrong direction, force flag may be used in addition to
commit flag to effectively terminate the existing connection and start
a new one in the current direction. This flag has no effect if the original
direction of the connection is already the same as that of the current
packet.
- table=table
- 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 (which may be specified as a number between 0 and
254 or, unless --no-names is specified, a name), with the
ct_state and other ct match fields set. If 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. 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. 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 must be specified to use
exec(...).
- alg=alg
- Specify application layer gateway alg to track specific connection
types. If subsequent related connections are sent through the ct
action, then the rel flag in the ct_state field will be set.
Supported types include:
- ftp
- Look for negotiation of FTP data connections. Specify this option for FTP
control connections to detect related data connections and populate the
rel flag for the data connections.
- tftp
- Look for negotiation of TFTP data connections. Specify this option for
TFTP control connections to detect related data connections and populate
the rel flag for the data connections.
- The commit parameter must be specified to use
alg=alg.
- 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=...)).
- Note that with the Linux datapath, global sysctl options affect the usage
of the ct action. In particular, if
net.netfilter.nf_conntrack_helper is enabled then application layer
gateway helpers may be executed even if the alg option is not
specified. This is the default setting until Linux 4.7. For security
reasons, the netfilter team recommends users to disable this option. See
this blog post for further details:
http://www.netfilter.org/news.html#2012-04-03
- nat[((src|dst)=addr1[-addr2][:port1[-port2]][,flags])]
- Specify address and port translation for the connection being tracked. For
new connections either src or dst argument must be provided
to set up either source address/port translation (SNAT) or destination
address/port translation (DNAT), respectively. Setting up address
translation for a new connection takes effect only if the commit
flag is also provided for the enclosing ct action. A bare
nat action will only translate the packet being processed in the
way the connection has been set up with an earlier ct action. Also
a nat action with src or dst, when applied to a
packet belonging to an established (rather than new) connection, will
behave the same as a bare nat.
- src and dst options take the following arguments:
- addr1[-addr2]
- The address range from which the translated address should be selected. If
only one address is given, then that address will always be selected,
otherwise the address selection can be informed by the optional
persistent flag as described below. Either IPv4 or IPv6 addresses
can be provided, but both addresses must be of the same type, and the
datapath behavior is undefined in case of providing IPv4 address range for
an IPv6 packet, or IPv6 address range for an IPv4 packet. IPv6 addresses
must be bracketed with '[' and ']' if a port range is also given.
- port1[-port2]
- The port range from which the translated port should be selected. If only
one port number is provided, then that should be selected. In case of a
mapping conflict the datapath may choose any other non-conflicting port
number instead, even when no port range is specified. The port number
selection can be informed by the optional random and hash
flags as described below.
- The optional flags are:
- random
- The selection of the port from the given range should be done using a
fresh random number. This flag is mutually exclusive with
hash.
- hash
- The selection of the port from the given range should be done using a
datapath specific hash of the packet's IP addresses and the other,
non-mapped port number. This flag is mutually exclusive with
random.
- persistent
- The selection of the IP address from the given range should be done so
that the same mapping can be provided after the system restarts.
- If an alg is specified for the committing ct action that
also includes nat with a src or dst attribute, then
the datapath tries to set up the helper to be NAT aware. This
functionality is datapath specific and may not be supported by all
datapaths.
- nat was introduced in Open vSwitch 2.6. The first datapath that
implements ct nat support is the one that ships with Linux
4.6.
- 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.
- The ct action was introduced in Open vSwitch 2.5.
- ct_clear
- Clears connection tracking state from the flow, zeroing ct_state,
ct_zone, ct_mark, and ct_label.
- This action was introduced in Open vSwitch 2.6.90.
- 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.
- dec_nsh_ttl
- Decrement TTL of the outer NSH header 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 may be NXM field names as defined in
nicira-ext.h, e.g. NXM_OF_UDP_SRC or NXM_NX_REG0, or
a match field name, e.g. 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 (in the latter case the brackets can also be left
off).
- 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:reg0[0..15]->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 can also be the NXM or OXM name for the
field. For example, load:0x001122334455->OXM_OF_ETH_SRC[] 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]
-
- pop:dst[start..end]
- These Open vSwitch extension actions act on bits start to
end, inclusive, in the named field, pushing or popping the bits on
a general-purpose stack of fields or subfields. Controllers can use this
stack for saving and restoring data or metadata around resubmit
actions, for swapping or rearranging data and metadata, or for other
purposes. Any data or metadata field, or part of one, may be pushed, and
any modifiable field or subfield may be popped.
- The number of bits pushed in a stack entry do not have to match the number
of bits later popped from that entry. If more bits are popped from an
entry than were pushed, then the entry is conceptually left-padded with
0-bits as needed. If fewer bits are popped than pushed, then bits are
conceptually trimmed from the left side of the entry.
- The stack's size is intended to have a large enough limit that ``normal''
use will not pose problems. Stack overflow or underflow is an error that
causes action execution to stop.
- Example: push:NXM_NX_REG2[0..5] or push:reg2[0..5] push the
value stored in register 2 bits 0 through 5, inclusive, on the internal
stack, and pop:NXM_NX_REG2[0..5] or pop:reg2[0..5] pops the
value from top of the stack and sets 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.
- nw_src
- Hashes Network source address only.
- nw_dst
- Hashes Network destination address only.
- 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, symmetric_l3l4+udp,
nw_src, or nw_dst, 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[]. Also the match field
name can be used, for example, instead of 'NXM_NX_REG0' the name 'reg0'
can be used. When the while field is indicated the empty brackets can also
be left off.
- 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=table
- The table in which the new flow should be inserted. Specify a decimal
number between 0 and 254 or (unless --no-names is specified) a
name. 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.
- limit=number
- If the number of flows in table table with cookie id cookie
exceeds number, a new flow will not be learned by this action. By
default there's no limit. limit=0 is a long-hand for no limit.
- This flag was added in Open vSwitch 2.8.
- result_dst=field[bit]
- If learning failed (because the number of flows exceeds limit), the
action sets field[bit] to 0, otherwise it will
be set to 1. field[bit] must be a single
bit.
- This flag was added in Open vSwitch 2.8.
- 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.
Shorthand notation matchers (e.g. ip in place of
dl_type=0x0800) are not currently implemented.
- The second form specifies that
field[start..end] in the new
flow must match src[start..end]
taken from the flow currently being processed. For example,
NXM_OF_UDP_DST []=NXM_OF_UDP_SRC[] on a TCP
packet for which the UDP src port is 53, creates a flow which
matches NXM_OF_UDP_DST[]=53.
- The third form is a shorthand for the second form. It specifies that
field [start..end] in the new
flow must match the same
field[start..end ] taken from
the flow currently being processed. For example,
NXM_OF_TCP_DST[] on a TCP packet for which the TCP dst port
is 80, creates a flow which matches
NXM_OF_TCP_DST[]=80.
- 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.
- 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.
- decap
- 3.
- encap
- 4.
- push_mpls
- 5.
- push_vlan
- 6.
- dec_ttl
-
- dec_mpls_ttl
-
- dec_nsh_ttl
- 7.
- 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.
- 8.
- set_queue
- 9.
- 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.
encap, decap and dec_nsh_ttl actions are
nonstandard.
- 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
- Jumps to table as the next table in the process pipeline. The
table may be a number between 0 and 254 or (unless
--no-names is specified) a name.
- 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.
- sampling_port=port
- Sample packets on port, which should be the ingress or egress port.
This option, which was added in Open vSwitch 2.5.90, allows the IPFIX
implementation to export egress tunnel information.
- ingress
-
- egress
- Specifies explicitly that the packet is being sampled on ingress to or
egress from the switch. IPFIX reports sent by Open vSwitch before version
2.5.90 did not include a direction. From 2.5.90 until 2.6.90, IPFIX
reports inferred a direction from sampling_port: if it was the
packet's output port, then the direction was reported as egress, otherwise
as ingress. Open vSwitch 2.6.90 introduced these options, which allow the
inferred direction to be overridden. This is particularly useful when the
ingress (or egress) port is not a tunnel.
- Refer to ovs-vswitchd.conf.db(5) 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)
- This action allows for sophisticated ``conjunctive match'' flows. Refer to
CONJUNCTIVE MATCH FIELDS in ovs-fields(7) for details.
- The conjunction action and conj_id field were introduced in
Open vSwitch 2.4.
- clone([action][,action...])
- Executes each nested action, saving much of the packet and pipeline
state beforehand and then restoring it afterward. The state that is saved
and restored includes all flow data and metadata (including, for example,
ct_state), the stack accessed by push and pop
actions, and the OpenFlow action set.
- This action was added in Open vSwitch 2.6.90.
- encap(header[(prop=value,tlv(class,type,value),...)])
- Encapsulates the packet with a new packet header, e.g., ethernet or
nsh.
- header
- Used to specify encapsulation header type.
- prop=value
- Used to specify the initial value for the property in the encapsulation
header.
- tlv(class,type,value)
- Used to specify the initial value for the TLV (Type Length Value) in the
encapsulation header.
- For example, encap(ethernet) will encapsulate the L3 packet with
Ethernet header.
- encap(nsh(md_type=1)) will encapsulate the packet with nsh header
and nsh metadata type 1.
- encap(nsh(md_type=2,tlv(0x1000,10,0x12345678))) will encapsulate
the packet with nsh header and nsh metadata type 2, and the nsh TLV with
class 0x1000 and type 10 is set to 0x12345678.
- prop=value is just used to set some necessary fields
for encapsulation header initialization. Other fields in the encapsulation
header must be set by set_field action. New encapsulation header
implementation must add new match fields and corresponding set
action in order that set_field action can change the fields in the
encapsulation header on demand.
- encap(nsh(md_type=1)),
set_field:0x1234->nsh_spi,set_field:0x11223344->nsh_c1 is an
example to encapsulate nsh header and set nsh spi and c1.
- This action was added in Open vSwitch 2.8.
- decap([packet_type(ns=namespace,type=type)])
- Decapsulates the outer packet header.
- packet_type(ns=namespace,type=type)
- It is optional and used to specify the outer header type of the
decapsulated packet. namespace is 0 for Ethernet packet, 1 for L3
packet, type is L3 protocol type, e.g., 0x894f for nsh, 0x0
for Ethernet.
- By default, decap() will decapsulate the outer packet header
according to the packet header type, if
packet_type(ns=namespace ,type=type) is
given, it will decapsulate the given packet header, it will fail if the
actual outer packet header type is not of
packet_type(ns=namespace
,type=type).
- This action was added in Open vSwitch 2.8.
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.)
- reset_counts
- When this flag is specified on a flow being added to a switch, and the
switch already has a flow with an identical match, an OpenFlow 1.2 (or
later) switch resets the flow's packet and byte counters to 0. Without the
flag, the packet and byte counters are preserved.
- OpenFlow 1.0 and 1.1 switches always reset counters in this situation, as
if reset_counts were always specified.
- Open vSwitch 1.10 added support for reset_counts.
- no_packet_counts
-
- no_byte_counts
- Adding these flags to a flow advises an OpenFlow 1.3 (or later) switch
that the controller does not need packet or byte counters, respectively,
for the flow. Some switch implementations might achieve higher performance
or reduce resource consumption when these flags are used. These flags
provide no benefit to the Open vSwitch software switch
implementation.
- OpenFlow 1.2 and earlier do not support these flags.
- Open vSwitch 1.10 added support for no_packet_counts and
no_byte_counts.
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.
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.
ovs-ofctl bundle command accepts packet-outs to be specified in the
bundle file. Each packet-out comprises of a series of
field=value assignments, separated by commas or white
space. (Embedding spaces into a packet-out 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. This same syntax is also supported by the ovs-ofctl
packet-out command.
- in_port=port
- The port number to be considered the in_port when processing actions. This
can be any valid OpenFlow port number, or any of the LOCAL,
CONTROLLER, or NONE. This field is required.
- pipeline_field=value
- Optionally, user can specify a list of pipeline fields for a packet-out
message. The supported pipeline fields includes tunnel fields and
register fields as defined in ovs-fields(7).
- packet=hex-string
- The actual packet to send, expressed as a string of hexadecimal bytes.
This field is required.
- actions=[action][,action...]
- The syntax of actions are identical to the actions= field described
in Flow Syntax above. Specifying actions= is optional, but
omitting actions is interpreted as a drop, so the packet will not be sent
anywhere from the switch. actions must be specified at the end of
each line, like for flow mods.
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, balancing across the buckets according to
their weights. To select a bucket, for each live bucket, Open vSwitch
hashes flow data with the bucket ID and multiplies by the bucket weight to
obtain a ``score,'' and then selects the bucket with the highest score.
Use selection_method to control the flow data used for
selection.
- 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. If no
selection method is specified, Open vSwitch up to release 2.9 applies the
hash method with default fields. From 2.10 onwards Open vSwitch
defaults to the dp_hash method with symmetric L3/L4 hash algorithm,
unless the weighted group buckets cannot be mapped to a maximum of 64
dp_hash values with sufficient accuracy. In those rare cases Open vSwitch
2.10 and later fall back to the hash method with the default set of
hash fields.
- dp_hash
- Use a datapath computed hash value. The hash algorithm varies accross
different datapath implementations. dp_hash uses the upper 32 bits
of the selection_method_param as the datapath hash algorithm
selector. The supported values are 0 (corresponding to hash
computation over the IP 5-tuple) and 1 (corresponding to a
symmetric hash computation over the IP 5-tuple). Selecting specific
fields with the fields option is not supported with
dp_hash). The lower 32 bits are used as the hash basis.
- Using dp_hash has the advantage that it does not require the
generated datapath flows to exact match any additional packet header
fields. For example, even if multiple TCP connections thus hashed to
different select group buckets have different source port numbers,
generally all of them would be handled with a small set of already
established datapath flows, resulting in less latency for TCP SYN packets.
The downside is that the shared datapath flows must match each packet
twice, as the datapath hash value calculation happens only when needed,
and a second match is required to match some bits of its value. This
double-matching incurs a small additional latency cost for each packet,
but this latency is orders of magnitude less than the latency of creating
new datapath flows for new TCP connections.
- hash
- Use a hash computed over the fields specified with the fields
option, see below. If no hash fields are specified, hash defaults
to a symmetric hash over the combination of MAC addresses, VLAN tags,
Ether type, IP addresses and L4 port numbers. hash uses the
selection_method_param as the hash basis.
- Note that the hashed fields become exact matched by the datapath flows.
For example, if the TCP source port is hashed, the created datapath flows
will match the specific TCP source port value present in the packet
received. Since each TCP connection generally has a different source port
value, a separate datapath flow will be need to be inserted for each TCP
connection thus hashed to a select group bucket.
- This option uses 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 uses 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 ``hash', 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. Specifying 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.
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 identifier for the meter. An integer is used to specify a user-defined
meter. In addition, the keywords "all", "controller",
and "slowpath", are also supported as virtual meters. The
"controller" and "slowpath" virtual meters apply to
packets sent to the controller and to the OVS userspace,
respectively.
- 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, except for meter-stats, which
dumps all stats when this field is not specified.
- kbps
-
- pktps
- The unit for the rate and burst_size band parameters.
kbps specifies kilobits per second, and pktps specifies
packets per second. A unit is required for the add-meter and
mod-meter commands.
- burst
- If set, enables burst support for meter bands through the
burst_size parameter.
- stats
- If set, enables the collection of 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 whether kbps or pktps was
specified.
- burst_size=size
- If burst is specified for the meter entry, configures the maximum
burst allowed for the band in kilobits or packets, depending on whether
kbps or pktps was specified. If unspecified, the switch is
free to select some reasonable value depending on its configuration.
- --strict
- Uses strict matching when running flow modification commands.
- --names
-
- --no-names
- Every OpenFlow port has a name and a number, and every OpenFlow flow table
has a number and sometimes a name. By default, ovs-ofctl commands
accept both port and table names and numbers, and they display port and
table names if ovs-ofctl is running on an interactive console,
numbers otherwise. With --names, ovs-ofctl commands both
accept and display port and table names; with --no-names, commands
neither accept nor display port and table names.
- If a port or table name contains special characters or might be confused
with a keyword within a flow, it may be enclosed in double quotes (escaped
from the shell). If necessary, JSON-style escape sequences may be used
inside quotes, as specified in RFC 7159. When it displays port and table
names, ovs-ofctl quotes any name that does not start with a letter
followed by letters or digits.
- Open vSwitch added support for port names and these options. Open vSwitch
2.10 added support for table names. Earlier versions always behaved as if
--no-names were specified.
- Open vSwitch does not place its own limit on the length of port names, but
OpenFlow 1.0 to 1.5 limit port names to 15 bytes and OpenFlow 1.6 limits
them to 63 bytes. Because ovs-ofctl uses OpenFlow to retrieve the mapping
between port names and numbers, names longer than this limit will be
truncated for both display and acceptance. Truncation can also cause long
names that are different to appear to be the same; when a switch has two
ports with the same (truncated) name, ovs-ofctl refuses to display
or accept the name, using the number instead.
- OpenFlow and Open vSwitch limit table names to 32 bytes.
- --stats
-
- --no-stats
- The dump-flows command by default, or with --stats, includes
flow duration, packet and byte counts, and idle and hard age in its
output. With --no-stats, it omits all of these, as well as cookie
values and table IDs if they are zero.
- --read-only
- Do not execute read/write 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.
- These protocol versions are enabled by default:
- •
- OpenFlow10, for OpenFlow 1.0.
The following protocol versions are generally supported, but for compatibility
with older versions of Open vSwitch they are not enabled by default:
- •
- OpenFlow11, for OpenFlow 1.1.
- •
- OpenFlow12, for OpenFlow 1.2.
- •
- OpenFlow13, for OpenFlow 1.3.
- •
- OpenFlow14, for OpenFlow 1.4.
- Support for the following protocol versions is provided for testing and
development purposes. They are not enabled by default:
- •
- OpenFlow15, for OpenFlow 1.5.
- •
- OpenFlow16, for OpenFlow 1.6.
- -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
-
- OXM-OpenFlow15
-
- OXM-OpenFlow16
- These are the standard OXM (OpenFlow Extensible Match) flow format in
OpenFlow 1.2 and later.
- 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:
- standard
- This uses the OFPT_PACKET_IN message, the standard ``packet-in''
message for any given OpenFlow version. Every OpenFlow switch that
supports a given OpenFlow version supports this format.
- nxt_packet_in
- This uses the NXT_PACKET_IN message, which adds many of the
capabilities of the OpenFlow 1.1 and later ``packet-in'' messages before
those OpenFlow versions were available in Open vSwitch. Open vSwitch 1.1
and later support this format. Only Open vSwitch 2.6 and later, however,
support it for OpenFlow 1.1 and later (but there is little reason to use
it with those versions of OpenFlow).
- nxt_packet_in2
- This uses the NXT_PACKET_IN2 message, which is extensible and
should avoid the need to define new formats later. In particular, this
format supports passing arbitrary user-provided data to a controller using
the userdata option on the controller action. Open
vSwitch 2.6 and later support this format.
- Without this option, ovs-ofctl prefers nxt_packet_in2 if the
switch supports it. Otherwise, if OpenFlow 1.0 is in use, ovs-ofctl
prefers nxt_packet_in if the switch supports it. Otherwise,
ovs-ofctl falls back to the standard packet-in format. When
this option is specified, ovs-ofctl insists on the selected format.
If the switch does not support the requested format, ovs-ofctl will
report a fatal error.
- Before version 2.6, Open vSwitch called standard format
openflow10 and nxt_packet_in format nxm, and
ovs-ofctl still accepts these names as synonyms. (The name
openflow10 was a misnomer because this format actually varies from
one OpenFlow version to another; it is not consistently OpenFlow 1.0
format. Similarly, when nxt_packet_in2 was introduced, the name
nxm became confusing because it also uses OXM/NXM.)
- This option affects only 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.
- --no-self-confinement
- By default daemon will try to self-confine itself to work with files under
well-know, at build-time whitelisted directories. It is better to stick
with this default behavior and not to use this flag unless some other
Access Control is used to confine daemon. Note that in contrast to other
access control implementations that are typically enforced from
kernel-space (e.g. DAC or MAC), self-confinement is imposed from the
user-space daemon itself and hence should not be considered as a full
confinement strategy, but instead should be viewed as an additional layer
of security.
- --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 that interact with a datapath,
such as ovs-vswitchd, will be granted three additional
capabilities, namely CAP_NET_ADMIN, CAP_NET_BROADCAST and CAP_NET_RAW. The
capability change will apply even if the 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 a local named pipe is used to listen for runtime management
commands. A file is created in the absolute path as pointed by
socket or if --unixctl is not used at all, a file is created
as ovs-ofctl.ctl in the configured OVS_RUNDIR directory. The
file exists just to mimic the behavior of a Unix domain socket.
- Specifying none for socket disables the control socket
feature.
- -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.
- --color[=when]
- Colorize the output (for some commands); when can be never,
always, or auto (the default).
Only some commands support output coloring. Color names and default colors may
change in future releases.
The environment variable OVS_COLORS can be used to specify user-defined
colors and other attributes used to highlight various parts of the output. If
set, its value is a colon-separated list of capabilities that defaults to
ac:01;31:dr=34:le=31:pm=36:pr=35:sp=33:vl=32. Supported capabilities
were initially designed for coloring flows from ovs-ofctl dump-flows
switch command, and they are as follows.
- ac=01;31
- SGR substring for actions= keyword in a flow. The default is a bold
red text foreground.
- dr=34
- SGR substring for drop keyword. The default is a dark blue text
foreground.
- le=31
- SGR substring for learn= keyword in a flow. The default is a red
text foreground.
- pm=36
- SGR substring for flow match attribute names. The default is a cyan text
foreground.
- pr=35
- SGR substring for keywords in a flow that are followed by arguments inside
parenthesis. The default is a magenta text foreground.
- sp=33
- SGR substring for some special keywords in a flow, notably: table=,
priority=, load:, output:, move:,
group:, CONTROLLER:, set_field:, resubmit:,
exit. The default is a yellow text foreground.
- vl=32
- SGR substring for a lone flow match attribute with no field name. The
default is a green text foreground.
See the Select Graphic Rendition (SGR) section in the documentation of the text
terminal that is used for permitted values and their meaning as character
attributes.
- -h
-
- --help
- Prints a brief help message to the console.
- -V
-
- --version
- Prints version information to the console.
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/packet-out packet-out
- Sends an OpenFlow PACKET_OUT message specified in Packet-Out
Syntax, on the OpenFlow connection. See Packet-Out Syntax
section for more information. 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.
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.
- ovs-ofctl add-flow table=0 actions=learn(table=1,hard_timeout=10,
NXM_OF_VLAN_TCI[0..11],output:NXM_OF_IN_PORT[]), resubmit(,1)
- ovs-ofctl add-flow table=1 priority=0 actions=flood Implements a
level 2 MAC learning switch using the learn.
- ovs-ofctl add-flow br0 'table=0,priority=0
actions=load:3->NXM_NX_REG0[0..15],learn(table=0,priority=1,idle_timeout=10,NXM_OF_ETH_SRC[],NXM_OF_VLAN_TCI[0..11],output:NXM_NX_REG0[0..15]),output:2
- In this use of a learn action, the first packet from each source MAC will
be sent to port 2. Subsequent packets will be output to port 3, with an
idle timeout of 10 seconds. NXM field names and match field names are both
accepted, e.g. NXM_NX_REG0 or reg0 for the first register,
and empty brackets may be omitted.
- Additional examples may be found documented as part of related
sections.
ovs-fields(7), ovs-appctl(8), ovs-vswitchd(8),
ovs-vswitchd.conf.db(8)
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