ovs-dpctl(8) — Linux manual page


ovs-dpctl(8)                 Open vSwitch Manual                ovs-dpctl(8)

NAME         top

       ovs-dpctl - administer Open vSwitch datapaths

SYNOPSIS         top

       ovs-dpctl [options] command [switch] [args...]

DESCRIPTION         top

       The ovs-dpctl program can create, modify, and delete Open vSwitch
       datapaths.  A single machine may host any number of datapaths.

       This program works only with datapaths that are implemented outside
       of ovs-vswitchd itself, such as the Linux and Windows kernel-based
       datapaths.  To manage datapaths that are integrated into
       ovs-vswitchd, such as the userspace (netdev) datapath, use
       ovs-appctl(8) to invoke the dpctl/* commands, which are documented in

       A newly created datapath is associated with only one network device,
       a virtual network device sometimes called the datapath's ``local
       port''.  A newly created datapath is not, however, associated with
       any of the host's other network devices.  To intercept and process
       traffic on a given network device, use the add-if command to
       explicitly add that network device to the datapath.

       If ovs-vswitchd(8) is in use, use ovs-vsctl(8) instead of ovs-dpctl.

       Most ovs-dpctl commands that work with datapaths take an argument
       that specifies the name of the datapath.  Datapath names take the
       form [type@]name, where name is the network device associated with
       the datapath's local port.  If type is given, it specifies the
       datapath provider of name, otherwise the default provider system is

       The following commands manage datapaths.  Do not use commands to add
       or remove or modify datapaths if ovs-vswitchd is running because this
       interferes with ovs-vswitchd's own datapath management.

       add-dp dp [netdev[,option]...]
              Creates datapath dp, with a local port also named dp.  This
              will fail if a network device dp already exists.

              If netdevs are specified, ovs-dpctl adds them to the new
              datapath, just as if add-if was specified.

       del-dp dp
              Deletes datapath dp.  If dp is associated with any network
              devices, they are automatically removed.

       add-if dp netdev[,option]...
              Adds each netdev to the set of network devices datapath dp
              monitors, where dp is the name of an existing datapath, and
              netdev is the name of one of the host's network devices, e.g.
              eth0.  Once a network device has been added to a datapath, the
              datapath has complete ownership of the network device's
              traffic and the network device appears silent to the rest of
              the system.

              A netdev may be followed by a comma-separated list of options.
              The following options are currently supported:

                     Specifies the type of port to add.  The default type is

                     Requests a specific port number within the datapath.
                     If this option is not specified then one will be
                     automatically assigned.

                     Adds an arbitrary key-value option to the port's

              ovs-vswitchd.conf.db(5) documents the available port types and

       set-if dp port[,option]...
              Reconfigures each port in dp as specified.  An option of the
              form key=value adds the specified key-value option to the port
              or overrides an existing key's value.  An option of the form
              key=, that is, without a value, deletes the key-value named
              key.  The type and port number of a port cannot be changed, so
              type and port_no are only allowed if they match the existing

       del-if dp netdev...
              Removes each netdev from the list of network devices datapath
              dp monitors.

              Prints the name of each configured datapath on a separate

       [-s | --statistics] show [dp...]
              Prints a summary of configured datapaths, including their
              datapath numbers and a list of ports connected to each
              datapath.  (The local port is identified as port 0.)  If -s or
              --statistics is specified, then packet and byte counters are
              also printed for each port.

              The datapath numbers consists of flow stats and mega flow mask

              The "lookups" row displays three stats related to flow lookup
              triggered by processing incoming packets in the datapath.
              "hit" displays number of packets matches existing flows.
              "missed" displays the number of packets not matching any
              existing flow and require user space processing.  "lost"
              displays number of packets destined for user space process but
              subsequently dropped before reaching userspace. The sum of
              "hit" and "miss" equals to the total number of packets
              datapath processed.

              The "flows" row displays the number of flows in datapath.

              The "masks" row displays the mega flow mask stats. This row is
              omitted for datapath not implementing mega flow. "hit"
              displays the total number of masks visited for matching
              incoming packets. "total" displays number of masks in the
              datapath. "hit/pkt" displays the average number of masks
              visited per packet; the ratio between "hit" and total number
              of packets processed by the datapath.

              If one or more datapaths are specified, information on only
              those datapaths are displayed.  Otherwise, ovs-dpctl displays
              information about all configured datapaths.

       The following commands are primarily useful for debugging Open
       vSwitch.  The flow table entries (both matches and actions) that they
       work with are not OpenFlow flow entries.  Instead, they are different
       and considerably simpler flows maintained by the Open vSwitch kernel
       module.  Do not use commands to add or remove or modify datapath
       flows if ovs-vswitchd is running because it interferes with
       ovs-vswitchd's own datapath flow management.  Use ovs-ofctl(8),
       instead, to work with OpenFlow flow entries.

       The dp argument to each of these commands is optional when exactly
       one datapath exists, in which case that datapath is the default.
       When multiple datapaths exist, then a datapath name is required.

       [-m | --more] [--names | --no-names] dump-flows [dp] [filter=filter]
              Prints to the console all flow entries in datapath dp's flow
              table.  Without -m or --more, output omits match fields that a
              flow wildcards entirely; with -m or --more, output includes
              all wildcarded fields.

              If filter=filter is specified, only displays the flows that
              match the filter. filter is a flow in the form similiar to
              that accepted by ovs-ofctl(8)'s add-flow command. (This is not
              an OpenFlow flow: besides other differences, it never contains
              wildcards.)  The filter is also useful to match wildcarded
              fields in the datapath flow. As an example,
              filter='tcp,tp_src=100' will match the datapath flow
              containing 'tcp(src=80/0xff00,dst=8080/0xff)'.

              If type=type is specified, only displays flows of the
              specified types.  This option supported only for ovs-appctl
              dpctl/dump-flows.  type is a comma separated list, which can
              contain any of the following:
                 ovs - displays flows handled in the ovs dp
                 tc - displays flows handled in the tc dp
                 dpdk - displays flows fully offloaded by dpdk
                 offloaded - displays flows offloaded to the HW
                 non-offloaded - displays flows not offloaded to the HW
                 partially-offloaded - displays flows where only part of
              their proccessing is done in HW
                 all - displays all the types of flows

              By default all the types of flows are displayed.  ovs-dpctl
              always acts as if the type was ovs.

       add-flow [dp] flow actions

       [--clear] [--may-create] [-s | --statistics] mod-flow [dp] flow
              Adds or modifies a flow in dp's flow table that, when a packet
              matching flow arrives, causes actions to be executed.

              The add-flow command succeeds only if flow does not already
              exist in dp.  Contrariwise, mod-flow without --may-create only
              modifies the actions for an existing flow.  With --may-create,
              mod-flow will add a new flow or modify an existing one.

              If -s or --statistics is specified, then mod-flow prints the
              modified flow's statistics.  A flow's statistics are the
              number of packets and bytes that have passed through the flow,
              the elapsed time since the flow last processed a packet (if
              ever), and (for TCP flows) the union of the TCP flags
              processed through the flow.

              With --clear, mod-flow zeros out the flow's statistics.  The
              statistics printed if -s or --statistics is also specified are
              those from just before clearing the statistics.

              NOTE: flow and actions do not match the syntax used with
              ovs-ofctl(8)'s add-flow command.

              Usage Examples

              Forward ARP between ports 1 and 2 on datapath myDP:

                     ovs-dpctl add-flow myDP \
                       "in_port(1),eth(),eth_type(0x0806),arp()" 2

                     ovs-dpctl add-flow myDP \
                       "in_port(2),eth(),eth_type(0x0806),arp()" 1

              Forward all IPv4 traffic between two addresses on ports 1 and

                     ovs-dpctl add-flow myDP \
                        ipv4(src=,dst=" 2

                     ovs-dpctl add-flow myDP \
                        ipv4(src=,dst=" 1

       [-s | --statistics] del-flow [dp] flow
              Deletes the flow from dp's flow table that matches flow.  If
              -s or --statistics is specified, then del-flow prints the
              deleted flow's statistics.

       [-m | --more] [--names | --no-names] get-flow [dp] ufid:ufid
              Fetches the flow from dp's flow table with unique identifier
              ufid.  ufid must be specified as a string of 32 hexadecimal

       del-flows [dp]
              Deletes all flow entries from datapath dp's flow table.

       The following commands are useful for debugging and configuring the
       connection tracking table in the datapath.

       The dp argument to each of these commands is optional when exactly
       one datapath exists, in which case that datapath is the default.
       When multiple datapaths exist, then a datapath name is required.

       N.B.(Linux specific): the system datapaths (i.e. the Linux kernel
       module Open vSwitch datapaths) share a single connection tracking
       table (which is also used by other kernel subsystems, such as
       iptables, nftables and the regular host stack).  Therefore, the
       following commands do not apply specifically to one datapath.

       ipf-set-enabled [dp] v4|v6
       ipf-set-disabled [dp] v4|v6
              Enables or disables IP fragmentation handling for the
              userspace connection tracker.  Either v4 or v6 must be
              specified.  Both IPv4 and IPv6 fragment reassembly are enabled
              by default.  Only supported for the userspace datapath.

       ipf-set-min-frag [dp] v4|v6 minfrag
              Sets the minimum fragment size (L3 header and data) for non-
              final fragments to minfrag.  Either v4 or v6 must be
              specified.  For enhanced DOS security, higher minimum fragment
              sizes can usually be used.  The default IPv4 value is 1200 and
              the clamped minimum is 400.  The default IPv6 value is 1280,
              with a clamped minimum of 400, for testing flexibility.  The
              maximum fragment size is not clamped, however, setting this
              value too high might result in valid fragments being dropped.
              Only supported for userspace datapath.

       ipf-set-max-nfrags [dp] maxfrags
              Sets the maximum number of fragments tracked by the userspace
              datapath connection tracker to maxfrags.  The default value is
              1000 and the clamped maximum is 5000.  Note that packet
              buffers can be held by the fragmentation module while
              fragments are incomplete, but will timeout after 15 seconds.
              Memory pool sizing should be set accordingly when
              fragmentation is enabled.  Only supported for userspace

       [-m | --more] ipf-get-status [dp]
              Gets the configuration settings and fragment counters
              associated with the fragmentation handling of the userspace
              datapath connection tracker.  With -m or --more, also dumps
              the IP fragment lists.  Only supported for userspace datapath.

       [-m | --more] [-s | --statistics] dump-conntrack [dp] [zone=zone]
              Prints to the console all the connection entries in the
              tracker used by dp.  If zone=zone is specified, only shows the
              connections in zone.  With --more, some implementation
              specific details are included. With --statistics timeouts and
              timestamps are added to the output.

       flush-conntrack [dp] [zone=zone] [ct-tuple]
              Flushes the connection entries in the tracker used by dp based
              on zone and connection tracking tuple ct-tuple.  If ct-tuple
              is not provided, flushes all the connection entries.  If
              zone=zone is specified, only flushes the connections in zone.

              If ct-tuple is provided, flushes the connection entry
              specified by ct-tuple in zone. The zone defaults to 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.  An example of an IPv4 ICMP ct-


              An example of an IPv6 TCP ct-tuple:


       [-m | --more] ct-stats-show [dp] [zone=zone]
              Displays the number of connections grouped by protocol used by
              dp.  If zone=zone is specified, numbers refer to the
              connections in zone.  With --more, groups by connection state
              for each protocol.

       ct-bkts [dp] [gt=threshold]
              For each conntrack bucket, displays the number of connections
              used by dp.  If gt=threshold is specified, bucket numbers are
              displayed when the number of connections in a bucket is
              greater than threshold.

       ct-set-maxconns [dp] maxconns
              Sets the maximum limit of connection tracker entries to
              maxconns on dp.  This can be used to reduce the processing
              load on the system due to connection tracking or simply
              limiting connection tracking.  If the number of connections is
              already over the new maximum limit request then the new
              maximum limit will be enforced when the number of connections
              decreases to that limit, which normally happens due to
              connection expiry.  Only supported for userspace datapath.

       ct-get-maxconns [dp]
              Prints the maximum limit of connection tracker entries on dp.
              Only supported for userspace datapath.

       ct-get-nconns [dp]
              Prints the current number of connection tracker entries on dp.
              Only supported for userspace datapath.

       ct-enable-tcp-seq-chk [dp]
       ct-disable-tcp-seq-chk [dp]
              Enables or disables TCP sequence checking.  When set to
              disabled, all sequence number verification is disabled,
              including for TCP resets.  This is similar, but not the same
              as 'be_liberal' mode, as in Netfilter.  Disabling sequence
              number verification is not an optimization in itself, but is
              needed for some hardware offload support which might offer
              some performance advantage. Sequence number checking is
              enabled by default to enforce better security and should only
              be disabled if required for hardware offload support.  This
              command is only supported for the userspace datapath.

       ct-get-tcp-seq-chk [dp]
              Prints whether TCP sequence checking is enabled or disabled on
              dp.  Only supported for the userspace datapath.

       ct-set-limits [dp] [default=default_limit] [zone=zone,limit=limit]...
              Sets the maximum allowed number of connections in a connection
              tracking zone.  A specific zone may be set to limit, and
              multiple zones may be specified with a comma-separated list.
              If a per-zone limit for a particular zone is not specified in
              the datapath, it defaults to the default per-zone limit.  A
              default zone may be specified with the default=default_limit
              argument.   Initially, the default per-zone limit is
              unlimited.  An unlimited number of entries may be set with 0

       ct-del-limits [dp] zone=zone[,zone]...
              Deletes the connection tracking limit for zone.  Multiple
              zones may be specified with a comma-separated list.

       ct-get-limits [dp] [zone=zone[,zone]...]
              Retrieves the maximum allowed number of connections and
              current counts per-zone.  If zone is given, only the specified
              zone(s) are printed.  If no zones are specified, all the zone
              limits and counts are provided.  The command always displays
              the default zone limit.

OPTIONS         top

              Limits ovs-dpctl runtime to approximately secs seconds.  If
              the timeout expires, ovs-dpctl will exit with a SIGALRM

              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-dpctl 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

              For compatibility with older versions of OVS, any is accepted
              as a word but has no effect.

              Sets the maximum logging verbosity level, equivalent to

              Sets the log pattern for destination to pattern.  Refer to
              ovs-appctl(8) for a description of the valid syntax for

              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.

              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

              Send syslog messages to UDP port on host, in addition to the
              system syslog.  The host must be a numerical IP address, not a

              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

              ·      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.

       --help Prints a brief help message to the console.

              Prints version information to the console.

SEE ALSO         top

       ovs-appctl(8), ovs-vswitchd(8)

COLOPHON         top

       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 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
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       this HTML version of the page, or you believe there is a better or
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       of the original manual page), send a mail to man-pages@man7.org

Open vSwitch                       2.13.90                      ovs-dpctl(8)

Pages that refer to this page: ovs-testcontroller(8)ovs-vswitchd(8)