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

       ovs-dpctl - administer Open vSwitch datapaths

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

       The ovs-dpctl program can create, modify, and delete Open vSwitch data‐
       paths.  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 data‐
       paths.  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 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 data‐
       path'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  in‐
       terferes 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  data‐
              path, just as if add-if was specified.

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

       add-if dp netdev[,option]...
              Adds each netdev to the set of network devices datapath dp moni‐
              tors,  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  automati‐
                     cally assigned.

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

              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 configu‐

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

              Prints the name of each configured datapath on a separate line.

       [-s | --statistics] show [dp...]
              Prints a summary of configured datapaths, including their  data‐
              path  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" dis‐
              plays the number of packets not matching any existing  flow  and
              require  user space processing.  "lost" displays number of pack‐
              ets destined for user space process but subsequently dropped be‐
              fore  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" dis‐
              plays the average number of masks visited per packet; the  ratio
              between "hit" and total number of packets processed by the data‐

              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 consid‐
       erably  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 mul‐
       tiple datapaths exist, then a datapath name is required.

       [-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 ta‐
              ble.   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,   fil‐
              ter='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  data‐

              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 al‐
              ways acts as if the type was ovs.

       add-flow [dp] flow actions

       [--clear] [--may-create] [-s | --statistics] mod-flow [dp] flow actions
              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 ex‐
              ist 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 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, mod‐
              ify, 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 modifi‐
              cations 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

       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 mul‐
       tiple datapaths exist, then a datapath name is required.

       N.B.(Linux specific): the system datapaths (i.e. the Linux kernel  mod‐
       ule  Open  vSwitch  datapaths) share a single connection tracking table
       (which is also used by other kernel subsystems, such as iptables, nfta‐
       bles 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-fi‐
              nal 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  in‐
              complete, 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  con‐
              nection  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 connec‐
              tions in zone.  With --more, some  implementation  specific  de‐
              tails  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  pro‐
              vided.   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-tuple:


              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 pro‐

       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 en‐
              forced 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  dis‐
              abled,  all  sequence number verification is disabled, including
              for TCP resets.  This is similar, but not the same  as  'be_lib‐
              eral'  mode, as in Netfilter.  Disabling sequence number verifi‐
              cation is not an optimization in itself, but is needed for  some
              hardware  offload support which might offer some performance ad‐
              vantage. Sequence number checking is enabled by default  to  en‐
              force  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 multi‐
              ple 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  unlim‐
              ited 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.

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

              Sets  logging  levels.  Without any spec, sets the log level for
              every module and destination to dbg.  Otherwise, spec is a  list
              of words separated by spaces or commas or colons, up to one from
              each category below:

              •      A valid module name, as displayed by the  vlog/list  com‐
                     mand on ovs-appctl(8), limits the log level change to the
                     specified module.

              •      syslog, console, or file, to limit the log  level  change
                     to  only to the system log, to the console, or to a file,
                     respectively.   (If  --detach  is  specified,   ovs-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 be‐

              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 --ver‐

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

              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  /usr/local/var/log/open‐

              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 dae‐
              mon.  Following forms are supported:

              •      libc, use libc syslog() function.  Downside of using this
                     options is that libc adds fixed prefix to  every  message
                     before  it  is  actually  sent  to the syslog daemon over
                     /dev/log UNIX domain socket.

              •      unix:file, use UNIX domain socket directly.  It is possi‐
                     ble to specify arbitrary message format with this option.
                     However, rsyslogd 8.9 and older versions use  hard  coded
                     parser  function  anyway  that  limits UNIX domain socket
                     use.  If you want to use arbitrary  message  format  with
                     older rsyslogd versions, then use UDP socket to localhost
                     IP address instead.

              •      udp:ip:port, use UDP socket.  With this method it is pos‐
                     sible  to  use  arbitrary  message format also with older
                     rsyslogd.  When sending syslog messages over  UDP  socket
                     extra  precaution needs to be taken into account, for ex‐
                     ample, syslog daemon needs to be configured to listen  on
                     the  specified  UDP port, accidental iptables rules could
                     be interfering with local syslog traffic  and  there  are
                     some  security  considerations that apply to UDP sockets,
                     but do not apply to UNIX domain sockets.

              •      null, discards all messages logged to syslog.

              The default is  taken  from  the  OVS_SYSLOG_METHOD  environment
              variable; if it is unset, the default is libc.

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

              Prints version information to the console.

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

Open vSwitch                         3.0.0                        ovs-dpctl(8)