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 ovs-vswitchd(8).

       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

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

       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 assumed.

       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

       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 system.

                     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 options.

       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 configuration.

       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 stats.

              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

              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

       [-m | --more] [--names | --no-names] dump-flows [dp]
       [filter=filter] [type=type] [pmd=pmd]
              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
              similar 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

              If pmd=pmd is specified, only displays flows of the
              specified pmd.  Using pmd=-1 will restrict the dump to
              flows from the main thread.  This option is only supported
              by the userspace datapath.

              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

              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

              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 2:

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

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

       add-flows [dp] file
       mod-flows [dp] file
       del-flows [dp] file
              Reads flow entries from file (or stdin if file is -) and
              adds, modifies, or deletes each entry to the datapath.
              Each flow specification (e.g., each line in file) may
              start with add, modify, or delete keyword to specify
              whether a flow is to be added, modified, or deleted. A
              flow specification without one of these keywords is
              treated based on the used command.  All flow modifications
              are executed as individual transactions in the order

       [-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 characters.

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

       The following commands are useful for debugging and configuring
       the datapath flow cache settings.

       cache-get-size [dp]
              Prints the current cache sizes to the console.

       cache-set-size dp cache size
              Set the dp's specific cache to the given size.  The cache
              name can be found by using the cache-get-size command.

       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

       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

       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 datapath.

       [-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.

       dump-conntrack-exp [dp] [zone=zone]
              Prints to the console all the expectation entries in the
              tracker used by dp.  If zone=zone is specified, only shows
              the expectations in zone. Only supported for userspace

       flush-conntrack [dp] [zone=zone] [ct-origin-tuple [ct-reply-
              Flushes the connection entries in the tracker used by dp
              based on zone and connection tracking tuple ct-origin-
              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-[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
              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-origin-tuple.

              Note: Currently there is a 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:


              An example of an IPv6 TCP ct-[orig|reply]-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

       ct-set-sweep-interval [dp] ms
              Sets the sweep interval. Only supported for the userspace

       ct-get-sweep-interval [dp]
              Prints the current sweep interval in ms. Only supported
              for the userspace datapath.

       ct-set-limits [dp] [default=default_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 limit.

       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

                     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.

              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 hostname.

              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.

       --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 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
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       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
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       (which is not part of the original manual page), send a mail to

Open vSwitch                     3.2.90                     ovs-dpctl(8)

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