ovs-ofctl(8) Open vSwitch Manual ovs-ofctl(8)
NAME
ovs-ofctl - administer OpenFlow switches
SYNOPSIS
ovs-ofctl [options] command [switch] [args...]
DESCRIPTION
The ovs-ofctl program is a command line tool for monitoring and admin‐
istering OpenFlow switches. It can also show the current state of an
OpenFlow switch, including features, configuration, and table entries.
It should work with any OpenFlow switch, not just Open vSwitch.
OpenFlow Switch Management Commands
These commands allow ovs-ofctl to monitor and administer an OpenFlow
switch. It is able to show the current state of a switch, including
features, configuration, and table entries.
Most of these commands take an argument that specifies the method for
connecting to an OpenFlow switch. The following connection methods are
supported:
ssl:host[:port]
tcp:host[:port]
The specified port on the given host, which can be ex‐
pressed either as a DNS name (if built with unbound li‐
brary) 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 repre‐
sented 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:/usr/local/var/run/open‐
vswitch/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 data‐
path provider of dp, otherwise the default provider sys‐
tem is assumed.
show switch
Prints to the console information on switch, including informa‐
tion 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 Open‐
Flow 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 op‐
tion) only, mod-table configures behavior when no flow is found
when a packet is looked up in a flow table. The following set‐
ting 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 1.3 and later (which must be enabled with the -O op‐
tion) and Open vSwitch 2.11 and later only, mod-table can change
the name of a table:
name:new-name
Changes the name of the table to new-name. Use an empty
new-name to clear the name. (This will be ineffective if
the name is set via the name column in the Flow_Table ta‐
ble in the Open_vSwitch database as described in
ovs-vswitchd.conf.db(5).)
In OpenFlow 1.4 and later (which must be enabled with the -O op‐
tion) only, mod-table configures the behavior when a controller
attempts to add a flow to a flow table that is full. The fol‐
lowing 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 en‐
abled through the overflow_policy column in the Flow_Ta‐
ble table documented in ovs-vswitchd.conf.db(5).)
vacancy:low,high
Enables sending vacancy events to controllers using TA‐
BLE_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 asso‐
ciated with that device will be printed. netdev can be an Open‐
Flow 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 sup‐
port 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 re‐
ceive-stp or no-receive-stp.
forward
no-forward
Allow or disallow forwarding of traffic to this inter‐
face. By default, forwarding is enabled.
flood
no-flood
Controls whether an OpenFlow flood action will send traf‐
fic 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 configu‐
ration 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 be‐
fore 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, in ovs-fields(7), for a way to
match on whether a packet is a fragment and on its fragment off‐
set.
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 con‐
sistent. 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 omit‐
ted, 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, sta‐
tistics 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.
OpenFlow Switch Flow Table Commands
These commands manage the flow table in an OpenFlow switch. In each
case, flow specifies a flow entry in the format described in Flow Syn‐
tax, 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 transaction, 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 mod‐
ify 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 dif‐
ferences. 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 +, respec‐
tively.
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 sec‐
tion.
Group Table Commands
These commands manage the group table in an OpenFlow switch. In each
case, group specifies a group entry in the format described in Group
Syntax, below, and file is a text file that contains zero or more
groups in the same syntax, one per line, and the optional --bundle op‐
tion operates the command as a single atomic transaction, 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 specifica‐
tion (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 key‐
words 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 specifi‐
cation 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.
OpenFlow 1.3+ Switch Meter Table Commands
These commands manage the meter table in an OpenFlow switch. In each
case, meter specifies a meter entry in the format described in Meter
Syntax, below.
OpenFlow 1.3 introduced support for meters, so these commands only work
with switches that support OpenFlow 1.3 or later. 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 de‐
scribed 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 spe‐
cific 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 spe‐
cific 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.
OpenFlow Switch Bundle Command
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 re‐
move_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 exe‐
cuted in the order specified.
OpenFlow Switch Tunnel TLV Table Commands
Open vSwitch maintains a mapping table between tunnel option TLVs (de‐
fined 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 op‐
tions. 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 map‐
ping 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 re‐
jected.
del-tlv-map switch [option[,option]]...
Delete each option from switch's table, or all option TLV map‐
ping if no option is specified. Fields that aren't mapped are
ignored.
dump-tlv-map switch
Show the currently mapped fields in the switch's option table as
well as switch capabilities.
OpenFlow Switch Monitoring Commands
snoop switch
Connects to switch and prints to the console all OpenFlow mes‐
sages 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 /usr/local/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 con‐
troller.
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 primary or a secondary (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 arbitrar‐
ily among them. If there is a primary controller, it is chosen;
otherwise, if there are any controllers that are not primaries
or secondaries, one is chosen arbitrarily; otherwise, a sec‐
ondary controller is chosen arbitrarily. This choice is made
once at connection time and does not change as controllers re‐
configure 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 mes‐
sages received. Usually, switch should specify the name of a
bridge in the ovs-vswitchd database. This is available only in
OpenFlow 1.0 as Nicira extension.
If miss-len is provided, ovs-ofctl sends an OpenFlow ``set con‐
figuration'' 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 speci‐
fied, very little traffic will ordinarily be printed.)
If invalid_ttl is passed, ovs-ofctl sends an OpenFlow ``set con‐
figuration'' message at connection setup time that requests IN‐
VALID_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 RUN‐
TIME 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).
out_group=group
If set, only flows that output to group number are moni‐
tored. This field requires OpenFlow 1.4 (-OOpenFlow14)
or later.
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 ob‐
serving how a controller updates flow tables.
OpenFlow Switch and Controller Commands
The following commands, like those in the previous section, may be ap‐
plied to OpenFlow switches, using any of the connection methods de‐
scribed in that section. Unlike those commands, these may also be ap‐
plied 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 run‐
ning.
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 Open‐
Flow header plus n bytes of payload and waits for each response.
Reports the total time required. This is a measure of the maxi‐
mum bandwidth to target for round-trips of n-byte messages.
Other Commands
ofp-parse file
Reads file (or stdin if file is -) as a series of OpenFlow mes‐
sages 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 mes‐
sages in those connections in human-readable format on stdout.
OpenFlow connections are distinguished by TCP port number. Non-
OpenFlow packets are ignored. By default, data on TCP ports
6633 and 6653 are considered to be OpenFlow. Specify one or
more port arguments to override the default.
This command cannot usefully print SSL encrypted traffic. It
does not understand IPv6.
Flow Syntax
Some ovs-ofctl commands accept an argument that describes a flow or
flows. Such flow descriptions comprise a series of field=value assign‐
ments, 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 ta‐
ble, 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 ta‐
bles.
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 Open‐
Flow 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 auto‐
matically detects whether the switch supports the exten‐
sion. 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 ta‐
ble=255).
OpenFlow 1.1
OpenFlow 1.1 requires flow table modification commands to
specify a table. When table is not specified (or ta‐
ble=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 out‐
put 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. See ovs-actions(7) for
details on the syntax and semantics of actions. K
An opaque identifier called a cookie can be used as a handle to iden‐
tify 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 num‐
ber and need not be unique among flows. If this field is omit‐
ted, 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 speci‐
fied.
priority=value
The priority at which a wildcarded entry will match in compari‐
son to others. value is a number between 0 and 65535, inclu‐
sive. 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 prior‐
ity 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 prece‐
dence 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 ex‐
piring due to inactivity.
hard_timeout=seconds
Causes the flow to expire after the given number of seconds, re‐
gardless 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 mecha‐
nism 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 sit‐
uation, 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 coun‐
ters, 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=group
If set, a matching flow must include an group action naming
group, which must be an OpenFlow group number. This field is
supported in Open vSwitch 2.5 and later and requires OpenFlow
1.1 or later.
Table Entry Output
The dump-tables and dump-aggregate commands print information about the
entries in a datapath's tables. Each line of output is a flow entry as
described in Flow Syntax, above, plus some additional fields:
duration=secs
The time, in seconds, that the entry has been in the table.
secs includes as much precision as the switch provides, possibly
to nanosecond resolution.
n_packets
The number of packets that have matched the entry.
n_bytes
The total number of bytes from packets that have matched the en‐
try.
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 modi‐
fied. 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 dura‐
tion.)
idle_age=secs
The integer number of seconds that have passed without any pack‐
ets passing through the flow.
Packet-Out Syntax
ovs-ofctl bundle command accepts packet-outs to be specified in the
bundle file. Each packet-out comprises of a series of field=value as‐
signments, 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 ac‐
tions. 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 tun‐
nel 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 de‐
scribed 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.
Group Syntax
Some ovs-ofctl commands accept an argument that describes a group or
groups. Such flow descriptions comprise a series field=value assign‐
ments, 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 other‐
wise 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 des‐
ignate 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 com‐
mands. 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 ob‐
tain 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 as‐
sociated 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 com‐
mands. 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 in‐
sert 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 ef‐
fect 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 in‐
sert 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 ef‐
fect 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 lay‐
ers. This field is optional for add-group, add-groups and
mod-group commands on groups of type select. Prohibited other‐
wise. 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, as long as the weighted group
buckets can be mapped to dp_hash values with sufficient accu‐
racy. In 2.10 this was restricted to a maximum of 64 buckets,
and in 2.17 the limit was raised to 256 buckets. 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 across different datapath implementations.
dp_hash uses the upper 32 bits of the selec‐
tion_method_param as the datapath hash algorithm selec‐
tor. 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). Se‐
lecting 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 addi‐
tional packet header fields. For example, even if multi‐
ple 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 es‐
tablished datapath flows, resulting in less latency for
TCP SYN packets. The downside is that the shared data‐
path 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 mag‐
nitude 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 speci‐
fied, hash defaults to a symmetric hash over the combina‐
tion of MAC addresses, VLAN tags, Ether type, IP ad‐
dresses and L4 port numbers. hash uses the selec‐
tion_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 spe‐
cific TCP source port value present in the packet re‐
ceived. Since each TCP connection generally has a dif‐
ferent 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 op‐
tional 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 selec‐
tion_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 Open‐
Flow 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 buck‐
ets. 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 con‐
sists 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 ver‐
sions of OpenFlow are used. Open vSwitch will automati‐
cally 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 inter‐
preted 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. This or the watch_group field can also
be used for groups whose type is select.
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. This or the
watch_port field can also be used for groups whose type
is select.
Meter Syntax
The meter table commands accept an argument that describes a meter.
Such meter descriptions comprise a series field=value assignments, sep‐
arated by commas or white space. (Embedding spaces into a group de‐
scription 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", "con‐
troller", 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 com‐
mands.
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 pack‐
ets, depending on whether kbps or pktps was specified.
If unspecified, the switch is free to select some reason‐
able value depending on its configuration.
OPTIONS
--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 ver‐
sions always behaved as if --no-names were specified.
Open vSwitch does not place its own limit on the length of port
names, but OpenFlow limits port names to 15 bytes. Because
ovs-ofctl uses OpenFlow to retrieve the mapping between port
names and numbers, names longer than this limit will be trun‐
cated 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 num‐
ber 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 ta‐
ble, 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 bun‐
dle control messages, which makes it possible to stream
the included commands without explicit OpenFlow barriers,
which are otherwise used after each flow table modifica‐
tion 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 en‐
able 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 estab‐
lishing an OpenFlow session.
These protocol versions are enabled by default:
• OpenFlow10, for OpenFlow 1.0.
The following protocol versions are generally supported, but for com‐
patibility 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.
• OpenFlow15, for OpenFlow 1.5.
-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 Open‐
Flow 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 exten‐
sible. 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
These are the standard OXM (OpenFlow Extensible Match)
flow format in OpenFlow 1.2 and later.
ovs-ofctl also supports the following abbreviations for collec‐
tions 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 ver‐
sion 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 avail‐
able 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 lit‐
tle 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 op‐
tion 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. Oth‐
erwise, 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 open‐
flow10 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 confus‐
ing 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 de‐
scending (--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.
Daemon Options
The following options are valid on POSIX based platforms.
--pidfile[=pidfile]
Causes a file (by default, ovs-ofctl.pid) to be created indicat‐
ing the PID of the running process. If the pidfile argument is
not specified, or if it does not begin with /, then it is cre‐
ated in /usr/local/var/run/openvswitch.
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified pid‐
file 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 (un‐
less --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 func‐
tions without it.
--no-chdir
By default, when --detach is specified, ovs-ofctl changes its
current working directory to the root directory after it de‐
taches. 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-known directories determined during build. 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 implemen‐
tations 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 COM‐
MANDS, below). If socket does not begin with /, it is inter‐
preted as relative to /usr/local/var/run/openvswitch. If
--unixctl is not used at all, the default socket is /usr/lo‐
cal/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 man‐
agement 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.
Public Key Infrastructure Options
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as
ovs-ofctl's identity for outgoing SSL connections.
-c cert.pem
--certificate=cert.pem
Specifies a PEM file containing a certificate that certifies the
private key specified on -p or --private-key to be trustworthy.
The certificate must be signed by the certificate authority (CA)
that the peer in SSL connections will use to verify it.
-C cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate that
ovs-ofctl should use to verify certificates presented to it by
SSL peers. (This may be the same certificate that SSL peers use
to verify the certificate specified on -c or --certificate, or
it may be a different one, depending on the PKI design in use.)
-C none
--ca-cert=none
Disables verification of certificates presented by SSL peers.
This introduces a security risk, because it means that certifi‐
cates 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 com‐
mand 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 be‐
low).
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 --ver‐
bose=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 /usr/local/var/log/open‐
vswitch/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 dae‐
mon. Following forms are supported:
• libc, use libc syslog() function. 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 possi‐
ble 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 pos‐
sible 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 ex‐
ample, 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.
• null, discards all messages logged to syslog.
The default is taken from the OVS_SYSLOG_METHOD environment
variable; if it is unset, the default is libc.
--color[=when]
Colorize the output (for some commands); when can be never, al‐
ways, or auto (the default).
Only some commands support output coloring. Color names and de‐
fault 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 capabil‐
ities 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 fol‐
lowed by arguments inside parenthesis. The de‐
fault 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 fore‐
ground.
See the Select Graphic Rendition (SGR) section in the documenta‐
tion 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.
RUNTIME MANAGEMENT COMMANDS
ovs-appctl(8) can send commands to a running ovs-ofctl process. The
supported commands are listed below.
exit Causes ovs-ofctl to gracefully terminate. This command applies
only when executing the monitor or snoop commands.
ofctl/set-output-file file
Causes all subsequent output to go to file instead of stderr.
This command applies only when executing the monitor or snoop
commands.
ofctl/send ofmsg...
Sends each ofmsg, specified as a sequence of hex digits that ex‐
press 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 sec‐
tion for more information. This command is useful only when ex‐
ecuting the monitor command.
ofctl/barrier
Sends an OpenFlow barrier request on the OpenFlow connection and
waits for a reply. This command is useful only for the monitor
command.
EXAMPLES
The following examples assume that ovs-vswitchd has a bridge named br0
configured.
ovs-ofctl dump-tables br0
Prints out the switch's table stats. (This is more interesting
after some traffic has passed through.)
ovs-ofctl dump-flows br0
Prints the flow entries in the switch.
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 ac‐
tions=load:3->NXM_NX_REG0[0..15],learn(table=0,priority=1,idle_time‐
out=10,NXM_OF_ETH_SRC[],NXM_OF_VLAN_TCI[0..11],out‐
put: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.
SEE ALSO
ovs-fields(7), ovs-actions(7), ovs-appctl(8), ovs-vswitchd(8),
ovs-vswitchd.conf.db(8)
Open vSwitch 3.0.0 ovs-ofctl(8)