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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | RUNTIME MANAGEMENT COMMANDS | EXAMPLES | SEE ALSO | COLOPHON |
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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.
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
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:/usr/local/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 1.3 and later (which must be enabled with the
-O option) 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 table 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 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, in ovs-fields(7), 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.
ct-flush switch [zone=N] [mark=X[/M]] [labels=Y[/N]] [ct-orig-
tuple [ct-reply-tuple]]
Flushes the connection entries on switch based on zone,
mark, labels and connection tracking tuples
ct-[orig|reply]-tuple.
If ct-[orig|reply]-tuple is not provided, flushes all the
connection entries. If zone is specified, only flushes the
connections in zone. if mark or labels is provided, it will
flush only entries that are matching specific mark/labels.
If ct-[orig|reply]-tuple is provided, flushes the
connection entry specified by ct-[orig|reply]-tuple in
zone. The zone defaults to 0 if it is not provided. The
mark and labels defaults to "0/0" if it is not provided.
The userspace connection tracker requires flushing with the
original pre-NATed tuple and a warning log will be
otherwise generated. The tuple can be partial and will
remove all connections that are matching on the specified
fields. In order to specify only ct-reply-tuple, provide
empty string as ct-orig-tuple.
Note: Currently there is limitation for matching on ICMP,
in order to partially match on ICMP parameters the
ct-[orig|reply]-tuple has to include either source or
destination IP.
An example of an IPv4 ICMP ct-[orig|reply]-tuple:
"ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=1,icmp_type=8,icmp_code=0,icmp_id=10"
An example of an IPv6 TCP ct-[orig|reply]-tuple:
"ct_ipv6_src=fc00::1,ct_ipv6_dst=fc00::2,ct_nw_proto=6,ct_tp_src=1,ct_tp_dst=2"
This command uses an Open vSwitch extension that is only in
Open vSwitch 3.1 and later. Support for matching on mark
and labels is only in Open vSwitch 3.3 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 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 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 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.
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 option 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
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.
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
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.
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 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.
OpenFlow Switch Tunnel TLV Table Commands
Open vSwitch maintains a mapping table between tunnel option TLVs
(defined by <class, type, length>) and NXM fields tun_metadatan,
where n ranges from 0 to 63, that can be operated on for the
purposes of matches, actions, etc. This TLV table can be used for
Geneve option TLVs or other protocols with options in same TLV
format as Geneve options. This mapping must be explicitly
specified by the user through the following commands.
A TLV mapping is specified with the syntax
{class=class,type=type,len=length}->tun_metadatan. When an option
mapping exists for a given tun_metadatan, matching on the defined
field becomes possible, e.g.:
ovs-ofctl add-tlv-map br0
"{class=0xffff,type=0,len=4}->tun_metadata0"
ovs-ofctl add-flow br0
tun_metadata0=1234,actions=controller
A mapping should not be changed while it is in active use by a
flow. The result of doing so is undefined.
These commands are Nicira extensions to OpenFlow and require Open
vSwitch 2.5 or later.
add-tlv-map switch option[,option]...
Add each option to switch's tables. Duplicate fields are
rejected.
del-tlv-map switch [option[,option]]...
Delete each option from switch's table, or all option TLV
mapping if no option is specified. Fields that aren't
mapped are ignored.
dump-tlv-map switch
Show the currently mapped fields in the switch's option
table as well as switch capabilities.
OpenFlow Switch Monitoring Commands
snoop switch
Connects to switch and prints to the console all OpenFlow
messages received. Unlike other ovs-ofctl commands, if
switch is the name of a bridge, then the snoop command
connects to a Unix domain socket named
/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 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 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 arbitrarily 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 secondary 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. This is available
only in OpenFlow 1.0 as Nicira extension.
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).
out_group=group
If set, only flows that output to group number are
monitored. 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 observing how a controller updates
flow tables.
OpenFlow Switch and Controller Commands
The following commands, like those in the previous section, may be
applied to OpenFlow switches, using any of the connection methods
described in that section. Unlike those commands, these may also
be applied to OpenFlow controllers.
probe target
Sends a single OpenFlow echo-request message to target and
waits for the response. With the -t or --timeout option,
this command can test whether an OpenFlow switch or
controller is up and running.
ping target [n]
Sends a series of 10 echo request packets to target and
times each reply. The echo request packets consist of an
OpenFlow header plus n bytes (default: 64) of randomly
generated payload. This measures the latency of individual
requests.
benchmark target n count
Sends count echo request packets that each consist of an
OpenFlow header plus n bytes of payload and waits for each
response. Reports the total time required. This is a
measure of the maximum bandwidth to target for round-trips
of n-byte messages.
Other Commands
ofp-parse file
Reads file (or stdin if file is -) as a series of OpenFlow
messages in the binary format used on an OpenFlow
connection, and prints them to the console. This can be
useful for printing OpenFlow messages captured from a TCP
stream.
ofp-parse-pcap file [port...]
Reads file, which must be in the PCAP format used by
network capture tools such as tcpdump or wireshark,
extracts all the TCP streams for OpenFlow connections, and
prints the OpenFlow messages in those connections in human-
readable format on stdout.
OpenFlow connections are distinguished by TCP port number.
Non-OpenFlow packets are ignored. By default, data on TCP
ports 6633 and 6653 are considered to be OpenFlow. Specify
one or more port arguments to override the default.
This command cannot usefully print SSL/TLS 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
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. 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
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=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 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.
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 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.
Group Syntax
Some ovs-ofctl commands accept an argument that describes a group
or groups. Such flow descriptions comprise a series field=value
assignments, separated by commas or white space. (Embedding
spaces into a group description normally requires quoting to
prevent the shell from breaking the description into multiple
arguments.). Unless noted otherwise only the last instance of each
field is honoured.
group_id=id
The integer group id of group. When this field is
specified in del-groups or dump-groups, the keyword "all"
may be used to designate all groups. This field is
required.
type=type
The type of the group. The add-group, add-groups and mod-
groups commands require this field. It is prohibited for
other commands. The following keywords designated the
allowed types:
all Execute all buckets in the group.
select Execute one bucket in the group, 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, as
long as the weighted group buckets can be mapped to dp_hash
values with sufficient accuracy. 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 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. 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, 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 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 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.
• 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
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
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.
Daemon Options
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 /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
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-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 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
/usr/local/var/run/openvswitch. If --unixctl is not used
at all, the default socket is
/usr/local/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.
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/TLS 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/TLS
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/TLS peers. (This may be the same certificate that
SSL/TLS 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/TLS
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
/usr/local/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. 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.
• 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,
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-actions(7), ovs-appctl(8), ovs-vswitchd(8),
ovs-vswitchd.conf.db(8)
This page is part of the Open vSwitch (a distributed virtual
multilayer switch) project. Information about the project can be
found at ⟨http://openvswitch.org/⟩. If you have a bug report for
this manual page, send it to bugs@openvswitch.org. This page was
obtained from the project's upstream Git repository
⟨https://github.com/openvswitch/ovs.git⟩ on 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-07-31.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Open vSwitch 3.4.90 ovs-ofctl(8)
Pages that refer to this page: ovs-actions(7), ovs-fields(7), ovs-dpctl(8), ovs-flowviz(8), ovs-l3ping(8), ovs-test(8), ovs-testcontroller(8), ovs-vlan-test(8), ovs-vswitchd(8)
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