ovs-vswitchd(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | RUNTIME MANAGEMENT COMMANDS | OPENFLOW IMPLEMENTATION | LIMITS | SEE ALSO | COLOPHON

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

NAME         top

       ovs-vswitchd - Open vSwitch daemon

SYNOPSIS         top

       ovs-vswitchd [database]

DESCRIPTION         top

       A daemon that manages and controls any number of Open vSwitch
       switches on the local machine.

       The database argument specifies how ovs-vswitchd connects to
       ovsdb-server.  database may be an OVSDB active or passive
       connection method, as described in ovsdb(7).  The default is
       unix:/usr/local/var/run/openvswitch/db.sock.

       ovs-vswitchd retrieves its configuration from database at
       startup.  It sets up Open vSwitch datapaths and then operates
       switching across each bridge described in its configuration
       files.  As the database changes, ovs-vswitchd automatically
       updates its configuration to match.

       ovs-vswitchd switches may be configured with any of the following
       features:

       •      L2 switching with MAC learning.

       •      NIC bonding with automatic fail-over and source MAC-based
              TX load balancing ("SLB").

       •      802.1Q VLAN support.

       •      Port mirroring, with optional VLAN tagging.

       •      NetFlow v5 flow logging.

       •      sFlow(R) monitoring.

       •      Connectivity to an external OpenFlow controller, such as
              NOX.

       Only a single instance of ovs-vswitchd is intended to run at a
       time.  A single ovs-vswitchd can manage any number of switch
       instances, up to the maximum number of supported Open vSwitch
       datapaths.

       ovs-vswitchd does all the necessary management of Open vSwitch
       datapaths itself.  Thus, ovs-dpctl(8) (and its userspace datapath
       counterparts accessible via ovs-appctl dpctl/command) are not
       needed with ovs-vswitchd and should not be used because they can
       interfere with its operation.  These tools are still useful for
       diagnostics.

       An Open vSwitch datapath kernel module must be loaded for
       ovs-vswitchd to be useful.  Refer to the documentation for
       instructions on how to build and load the Open vSwitch kernel
       module.

OPTIONS         top

       --mlockall
              Causes ovs-vswitchd to call the mlockall() function, to
              attempt to lock all of its process memory into physical
              RAM, preventing the kernel from paging any of its memory
              to disk.  This helps to avoid networking interruptions due
              to system memory pressure.

              Some systems do not support mlockall() at all, and other
              systems only allow privileged users, such as the
              superuser, to use it.  ovs-vswitchd emits a log message if
              mlockall() is unavailable or unsuccessful.

   DPDK Options
       For details on initializing ovs-vswitchd to use DPDK ports, refer
       to the documentation or ovs-vswitchd.conf.db(5).

   Daemon Options
       The following options are valid on POSIX based platforms.

       --pidfile[=pidfile]
              Causes a file (by default, ovs-vswitchd.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-vswitchd 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-vswitchd 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-vswitchd detaches only after it has
              connected to the database, retrieved the initial
              configuration, and set up that configuration.

       --monitor
              Creates an additional process to monitor the ovs-vswitchd
              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-vswitchd
              changes its current working directory to the root
              directory after it detaches.  Otherwise, invoking
              ovs-vswitchd 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-vswitchd 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-vswitchd 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.

   Service Options
       The following options are valid only on Windows platform.

       --service
              Causes ovs-vswitchd to run as a service in the background.
              The service should already have been created through
              external tools like SC.exe.

       --service-monitor
              Causes the ovs-vswitchd service to be automatically
              restarted by the Windows services manager if the service
              dies or exits for unexpected reasons.

              When --service is not specified, this option has no
              effect.

   Public Key Infrastructure Options
       -p privkey.pem
       --private-key=privkey.pem
              Specifies a PEM file containing the private key used as
              ovs-vswitchd's identity for outgoing SSL connections.

       -c cert.pem
       --certificate=cert.pem
              Specifies a PEM file containing a certificate that
              certifies the private key specified on -p or --private-key
              to be trustworthy.  The certificate must be signed by the
              certificate authority (CA) that the peer in SSL
              connections will use to verify it.

       -C cacert.pem
       --ca-cert=cacert.pem
              Specifies a PEM file containing the CA certificate that
              ovs-vswitchd should use to verify certificates presented
              to it by SSL peers.  (This may be the same certificate
              that SSL peers use to verify the certificate specified on
              -c or --certificate, or it may be a different one,
              depending on the PKI design in use.)

       -C none
       --ca-cert=none
              Disables verification of certificates presented by SSL
              peers.  This introduces a security risk, because it means
              that certificates cannot be verified to be those of known
              trusted hosts.

       --bootstrap-ca-cert=cacert.pem
              When cacert.pem exists, this option has the same effect as
              -C or --ca-cert.  If it does not exist, then ovs-vswitchd
              will attempt to obtain the CA certificate from the SSL
              peer on its first SSL connection and save it to the named
              PEM file.  If it is successful, it will immediately drop
              the connection and reconnect, and from then on all SSL
              connections must be authenticated by a certificate signed
              by the CA certificate thus obtained.

              This option exposes the SSL connection to a man-in-the-
              middle attack obtaining the initial CA certificate, but it
              may be useful for bootstrapping.

              This option is only useful if the SSL peer sends its CA
              certificate as part of the SSL certificate chain.  The SSL
              protocol does not require the server to send the CA
              certificate.

              This option is mutually exclusive with -C and --ca-cert.

       --peer-ca-cert=peer-cacert.pem
              Specifies a PEM file that contains one or more additional
              certificates to send to SSL peers.  peer-cacert.pem should
              be the CA certificate used to sign ovs-vswitchd's own
              certificate, that is, the certificate specified on -c or
              --certificate.  If ovs-vswitchd's certificate is self-
              signed, then --certificate and --peer-ca-cert should
              specify the same file.

              This option is not useful in normal operation, because the
              SSL peer must already have the CA certificate for the peer
              to have any confidence in ovs-vswitchd's identity.
              However, this offers a way for a new installation to
              bootstrap the CA certificate on its first SSL connection.

   Logging Options
       -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-vswitchd 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-vswitchd.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.

   Other Options
       --unixctl=socket
              Sets the name of the control socket on which ovs-vswitchd
              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-vswitchd.pid.ctl, where
              pid is ovs-vswitchd'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-vswitchd.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.

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

       -V
       --version
              Prints version information to the console.

RUNTIME MANAGEMENT COMMANDS         top

       ovs-appctl(8) can send commands to a running ovs-vswitchd
       process.  The currently supported commands are described below.
       The command descriptions assume an understanding of how to
       configure Open vSwitch.

   GENERAL COMMANDS
       exit --cleanup
              Causes ovs-vswitchd to gracefully terminate. If --cleanup
              is specified, deletes flows from datapaths and releases
              other datapath resources configured by ovs-vswitchd.
              Otherwise, datapath flows and other resources remains
              undeleted.  Resources of datapaths that are integrated
              into ovs-vswitchd (e.g.  the netdev datapath type) are
              always released regardless of --cleanup except for ports
              with internal type. Use --cleanup to release internal
              ports too.

       qos/show-types interface
              Queries the interface for a list of Quality of Service
              types that are configurable via Open vSwitch for the given
              interface.

       qos/show interface
              Queries the kernel for Quality of Service configuration
              and statistics associated with the given interface.

       bfd/show [interface]
              Displays detailed information about Bidirectional
              Forwarding Detection configured on interface.  If
              interface is not specified, then displays detailed
              information about all interfaces with BFD enabled.

       bfd/set-forwarding [interface] status
              Force the fault status of the BFD module on interface (or
              all interfaces if none is given) to be status.  status can
              be "true", "false", or "normal" which reverts to the
              standard behavior.

       cfm/show [interface]
              Displays detailed information about Connectivity Fault
              Management configured on interface.  If interface is not
              specified, then displays detailed information about all
              interfaces with CFM enabled.

       cfm/set-fault [interface] status
              Force the fault status of the CFM module on interface (or
              all interfaces if none is given) to be status.  status can
              be "true", "false", or "normal" which reverts to the
              standard behavior.

       stp/tcn [bridge]
              Forces a topology change event on bridge if it's running
              STP.  This may cause it to send Topology Change
              Notifications to its peers and flush its MAC table.  If no
              bridge is given, forces a topology change event on all
              bridges.

       stp/show [bridge]
              Displays detailed information about spanning tree on the
              bridge.  If bridge is not specified, then displays
              detailed information about all bridges with STP enabled.

       rstp/tcn [bridge]
              Forces a topology change event on bridge if it's running
              RSTP.  This may cause it to send Topology Change
              Notifications to its peers and flush its MAC table.  If no
              bridge is given, forces a topology change event on all
              bridges.

       rstp/show [bridge]
              Displays detailed information about rapid spanning tree on
              the bridge.  If bridge is not specified, then displays
              detailed information about all bridges with RSTP enabled.

   BRIDGE COMMANDS
       These commands manage bridges.

       fdb/flush [bridge]
              Flushes bridge MAC address learning table, or all learning
              tables if no bridge is given.

       fdb/show bridge
              Lists each MAC address/VLAN pair learned by the specified
              bridge, along with the port on which it was learned and
              the age of the entry, in seconds.

       fdb/stats-clear [bridge]
              Clear bridge MAC address learning table statistics, or all
              statistics if no bridge is given.

       fdb/stats-show bridge
              Show MAC address learning table statistics for the
              specified bridge.

       mdb/flush [bridge]
              Flushes bridge multicast snooping table, or all snooping
              tables if no bridge is given.

       mdb/show bridge
              Lists each multicast group/VLAN pair learned by the
              specified bridge, along with the port on which it was
              learned and the age of the entry, in seconds.

       bridge/reconnect [bridge]
              Makes bridge drop all of its OpenFlow controller
              connections and reconnect.  If bridge is not specified,
              then all bridges drop their controller connections and
              reconnect.

              This command might be useful for debugging OpenFlow
              controller issues.

       bridge/dump-flows [--offload-stats] bridge
              Lists all flows in bridge, including those normally hidden
              to commands such as ovs-ofctl dump-flows.  Flows set up by
              mechanisms such as in-band control and fail-open are
              hidden from the controller since it is not allowed to
              modify or override them.  If --offload-stats are specified
              then also list statistics for offloaded packets and bytes,
              which are a subset of the total packets and bytes.

   BOND COMMANDS
       These commands manage bonded ports on an Open vSwitch's bridges.
       To understand some of these commands, it is important to
       understand a detail of the bonding implementation called ``source
       load balancing'' (SLB).  Instead of directly assigning Ethernet
       source addresses to members, the bonding implementation computes
       a function that maps an 48-bit Ethernet source addresses into an
       8-bit value (a ``MAC hash'' value).  All of the Ethernet
       addresses that map to a single 8-bit value are then assigned to a
       single member.

       bond/list
              Lists all of the bonds, and their members, on each bridge.

       bond/show [port]
              Lists all of the bond-specific information (updelay,
              downdelay, time until the next rebalance) about the given
              bonded port, or all bonded ports if no port is given.
              Also lists information about each members: whether it is
              enabled or disabled, the time to completion of an updelay
              or downdelay if one is in progress, whether it is the
              active member, the hashes assigned to the member.  Any
              LACP information related to this bond may be found using
              the lacp/show command.

       bond/migrate port hash member
              Only valid for SLB bonds.  Assigns a given MAC hash to a
              new member.  port specifies the bond port, hash the MAC
              hash to be migrated (as a decimal number between 0 and
              255), and member the new member to be assigned.

              The reassignment is not permanent: rebalancing or fail-
              over will cause the MAC hash to be shifted to a new member
              in the usual manner.

              A MAC hash cannot be migrated to a disabled member.

       bond/set-active-member port member
              Sets member as the active member on port.  member must
              currently be enabled.

              The setting is not permanent: a new active member will be
              selected if member becomes disabled.

       bond/enable-member port member
       bond/disable-member port member
              Enables (or disables) member on the given bond port,
              skipping any updelay (or downdelay).

              This setting is not permanent: it persists only until the
              carrier status of member changes.

       bond/hash mac [vlan] [basis]
              Returns the hash value which would be used for mac with
              vlan and basis if specified.

       lacp/show [port]
              Lists all of the LACP related information about the given
              port: active or passive, aggregation key, system id, and
              system priority.  Also lists information about each
              member: whether it is enabled or disabled, whether it is
              attached or detached, port id and priority, actor
              information, and partner information.  If port is not
              specified, then displays detailed information about all
              interfaces with CFM enabled.

       lacp/stats-show [port]
              Lists various stats about LACP PDUs (number of RX/TX PDUs,
              bad PDUs received) and member state (number of times its
              state expired/defaulted and carrier status changed) for
              the given port.  If port is not specified, then displays
              stats of all interfaces with LACP enabled.

   DPCTL DATAPATH DEBUGGING COMMANDS
       The primary way to configure ovs-vswitchd is through the Open
       vSwitch database, e.g. using ovs-vsctl(8).  These commands
       provide a debugging interface for managing datapaths.  They
       implement the same features (and syntax) as ovs-dpctl(8).  Unlike
       ovs-dpctl(8), these commands work with datapaths that are
       integrated into ovs-vswitchd (e.g. the netdev datapath type).

       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.

       dpctl/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-vswitchd adds them to the
              new datapath, just as if add-if was specified.

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

       dpctl/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:

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

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

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

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

       dpctl/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.

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

       dpctl/dump-dps
              Prints the name of each configured datapath on a separate
              line.

       dpctl/show [-s | --statistics] [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
              datapath.

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

   DATAPATH FLOW TABLE DEBUGGING COMMANDS
       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.

       dpctl/dump-flows [-m | --more] [--names | --no-names] [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
              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 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.

       dpctl/add-flow [dp] flow actions

       dpctl/mod-flow [--clear] [--may-create] [-s | --statistics] [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 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 2:

                     ovs-dpctl add-flow myDP \
                       "in_port(1),eth(),eth_type(0x800),\
                        ipv4(src=172.31.110.4,dst=172.31.110.5)" 2

                     ovs-dpctl add-flow myDP \
                       "in_port(2),eth(),eth_type(0x800),\
                        ipv4(src=172.31.110.5,dst=172.31.110.4)" 1

       dpctl/add-flows [dp] file
       dpctl/mod-flows [dp] file
       dpctl/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
              specified.

       dpctl/del-flow [-s | --statistics] [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.

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

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

   CONNECTION TRACKING TABLE COMMANDS
       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.

       dpctl/ipf-set-enabled [dp] v4|v6
       dpctl/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.

       dpctl/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.

       dpctl/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.

       dpctl/ipf-get-status [dp] [-m | --more]
              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.

       dpctl/dump-conntrack [-m | --more] [-s | --statistics] [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.

       dpctl/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-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-tuple:

              "ct_ipv6_src=fc00::1,ct_ipv6_dst=fc00::2,ct_nw_proto=6,ct_tp_src=1,ct_tp_dst=2"

       dpctl/ct-stats-show [dp] [zone=zone] [-m | --more]
              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.

       dpctl/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.

       dpctl/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.

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

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

       dpctl/ct-enable-tcp-seq-chk [dp]
       dpctl/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.

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

       dpctl/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 limit.

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

       dpctl/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.

   DPDK COMMANDS
       These commands manage DPDK components.

       dpdk/log-list
              Lists all DPDK components that emit logs and their logging
              levels.

       dpdk/log-set [spec]
              Sets DPDK components logging level. Without any spec, sets
              the logging level for all DPDK components to debug.
              Otherwise, spec is a list of words separated by spaces: a
              word can be either a logging level (emergency, alert,
              critical, error, warning, notice, info or debug) or a
              pattern matching DPDK components (see dpdk/log-list
              command on ovs-appctl(8)) separated by a colon from the
              logging level to apply.

   DPIF-NETDEV COMMANDS
       These commands are used to expose internal information (mostly
       statistics) about the "dpif-netdev" userspace datapath. If there
       is only one datapath (as is often the case, unless dpctl/
       commands are used), the dp argument can be omitted. By default
       the commands present data for all pmd threads in the datapath. By
       specifying the "-pmd Core" option one can filter the output for a
       single pmd in the datapath.

       dpif-netdev/pmd-stats-show [-pmd core] [dp]
              Shows performance statistics for one or all pmd threads of
              the datapath dp. The special thread "main" sums up the
              statistics of every non pmd thread.

              The sum of "emc hits", "smc hits", "megaflow hits" and
              "miss" is the number of packet lookups performed by the
              datapath. Beware that a recirculated packet experiences
              one additional lookup per recirculation, so there may be
              more lookups than forwarded packets in the datapath.

              Cycles are counted using the TSC or similar facilities
              (when available on the platform). The duration of one
              cycle depends on the processing platform.

              "idle cycles" refers to cycles spent in PMD iterations not
              forwarding any any packets. "processing cycles" refers to
              cycles spent in PMD iterations forwarding at least one
              packet, including the cost for polling, processing and
              transmitting said packets.

              To reset these counters use dpif-netdev/pmd-stats-clear.

       dpif-netdev/pmd-stats-clear [dp]
              Resets to zero the per pmd thread performance numbers
              shown by the dpif-netdev/pmd-stats-show and dpif-
              netdev/pmd-perf-show commands.  It will NOT reset datapath
              or bridge statistics, only the values shown by the above
              commands.

       dpif-netdev/pmd-perf-show [-nh] [-it iter_len] [-ms ms_len] [-pmd
       core] [dp]
              Shows detailed performance metrics for one or all pmds
              threads of the user space datapath.

              The collection of detailed statistics can be controlled by
              a new configuration parameter "other_config:pmd-perf-
              metrics". By default it is disabled. The run-time
              overhead, when enabled, is in the order of 1%.

              —      used cycles
              —      forwared packets
              —      number of rx batches
              —      packets/rx batch
              —      max. vhostuser queue fill level
              —      number of upcalls
              —      cycles spent in upcalls

              This raw recorded data is used threefold:

              1.     In histograms for each of the following metrics:
                     —      cycles/iteration (logarithmic)
                     —      packets/iteration (logarithmic)
                     —      cycles/packet
                     —      packets/batch
                     —      max. vhostuser qlen (logarithmic)
                     —      upcalls
                     —      cycles/upcall (logarithmic) The histograms
                            bins are divided linear or logarithmic.
              2.     A cyclic history of the above metrics for 1024
                     iterations
              3.     A cyclic history of the cummulative/average values
                     per millisecond wall clock for the last 1024
                     milliseconds:
                     —      number of iterations
                     —      avg. cycles/iteration
                     —      packets (Kpps)
                     —      avg. packets/batch
                     —      avg. max vhost qlen
                     —      upcalls
                     —      avg. cycles/upcall

              The command options are:

              -nh    Suppress the histograms

              -it iter_len
                     Display the last iter_len iteration stats

              -ms ms_len
                     Display the last ms_len millisecond stats

              The output always contains the following global PMD
              statistics:

                     Time: 15:24:55.270
                     Measurement duration: 1.008 s

                     pmd thread numa_id 0 core_id 1:

                       Iterations:              572817  (1.76 us/it)
                       - Used TSC cycles:   2419034712  ( 99.9 % of total cycles)
                       - idle iterations:       486808  ( 15.9 % of used cycles)
                       - busy iterations:        86009  ( 84.1 % of used cycles)
                       Rx packets:             2399607  (2381 Kpps, 848 cycles/pkt)
                       Datapath passes:        3599415  (1.50 passes/pkt)
                       - EMC hits:              336472  (  9.3 %)
                       - SMC hits:                   0  ( 0.0 %)
                       - Megaflow hits:        3262943  ( 90.7 %, 1.00 subtbl lookups/hit)
                       - Upcalls:                    0  (  0.0 %, 0.0 us/upcall)
                       - Lost upcalls:               0  (  0.0 %)
                       Tx packets:             2399607  (2381 Kpps)
                       Tx batches:              171400  (14.00 pkts/batch)

              Here "Rx packets" actually reflects the number of packets
              forwarded by the datapath. "Datapath passes" matches the
              number of packet lookups as reported by the dpif-
              netdev/pmd-stats-show command.

              To reset the counters and start a new measurement use
              dpif-netdev/pmd-stats-clear.

       dpif-netdev/pmd-perf-log-set on|off [-b before] [-a after]
       [-e|-ne] [-us usec] [-q qlen]
              The userspace "netdev" datapath is able to supervise the
              PMD performance metrics and detect iterations with
              suspicious statistics according to the following criteria:

              —      The iteration lasts longer than usec microseconds
                     (default 250).  This can be used to capture events
                     where a PMD is blocked or interrupted for such a
                     period of time that there is a risk for dropped
                     packets on any of its Rx queues.

              —      The max vhost qlen exceeds a threshold qlen
                     (default 128). This can be used to infer virtio
                     queue overruns and dropped packets inside a VM,
                     which are not visible in OVS otherwise.

              Such suspicious iterations can be logged together with
              their iteration statistics in the ovs-vswitchd.log to be
              able to correlate them to packet drop or other events
              outside OVS.

              The above command enables (on) or disables (off)
              supervision and logging at run-time and can be used to
              adjust the above thresholds for detecting suspicious
              iterations. By default supervision and logging is
              disabled.

              The command options are:

              -b before
                     The number of iterations before the suspicious
                     iteration to be logged (default 5).

              -a after
                     The number of iterations after the suspicious
                     iteration to be logged (default 5).

              -e     Extend logging interval if another suspicious
                     iteration is detected before logging occurs.

              -ne    Do not extend logging interval if another
                     suspicious iteration is detected before logging
                     occurs (default).

              -q qlen
                     Suspicious vhost queue fill level threshold.
                     Increase this to 512 if the Qemu supports 1024
                     virtio queue length (default 128).

              -us usec
                     Change the duration threshold for a suspicious
                     iteration (default 250 us).

       Note: Logging of suspicious iterations itself consumes a
       considerable amount of processing cycles of a PMD which may be
       visible in the iteration history.  In the worst case this can
       lead OVS to detect another suspicious iteration caused by
       logging.

       If more than 100 iterations around a suspicious iteration have
       been logged once, OVS falls back to the safe default values (-b 5
       -a 5 -ne) to avoid that logging itself continuously causes
       logging of further suspicious iterations.

       dpif-netdev/pmd-rxq-show [-pmd core] [dp]
              For one or all pmd threads of the datapath dp show the
              list of queue-ids with port names, which this thread
              polls.

       dpif-netdev/pmd-rxq-rebalance [dp]
              Reassigns rxqs to pmds in the datapath dp based on their
              current usage.

       dpif-netdev/bond-show [dp]
              When "other_config:lb-output-action" is set to "true", the
              userspace datapath handles the load balancing of bonds
              directly instead of depending on flow recirculation (only
              in balance-tcp mode).

              When this is the case, the above command prints the load-
              balancing information of the bonds configured in datapath
              dp showing the interface associated with each bucket
              (hash).

   NETDEV-DPDK COMMANDS
       These commands manage DPDK related ports (type=dpdk*).

       netdev-dpdk/set-admin-state [interface] up | down
              Change the admin state for DPDK interface to up or down.
              If interface is not specified, then it applies to all DPDK
              ports.

       netdev-dpdk/detach pci-address
              Detaches device with corresponding pci-address from DPDK.
              This command can be used to detach device if it wasn't
              detached automatically after port deletion. Refer to the
              documentation for details and instructions.

       netdev-dpdk/get-mempool-info [interface]
              Prints the debug information about memory pool used by
              DPDK interface.  If called without arguments, information
              of all the available mempools will be printed. For
              additional mempool statistics enable
              CONFIG_RTE_LIBRTE_MEMPOOL_DEBUG while building DPDK.

   DATAPATH DEBUGGING COMMANDS
       These commands query and modify datapaths.  They are are similar
       to ovs-dpctl(8) commands.  dpif/show has the additional
       functionality, beyond dpctl/show of printing OpenFlow port
       numbers.  The other commands are redundant and will be removed in
       a future release.

       dpif/dump-dps
              Prints the name of each configured datapath on a separate
              line.

       dpif/show
              Prints a summary of configured datapaths, including
              statistics and a list of connected ports.  The port
              information includes the OpenFlow port number, datapath
              port number, and the type.  (The local port is identified
              as OpenFlow port 65534.)

       dpif/dump-flows [-m] dp
              Prints to the console all flow entries in datapath dp's
              flow table. Without -m, output omits match fields that a
              flow wildcards entirely; with -m output includes all
              wildcarded fields.

              This command is primarily useful for debugging Open
              vSwitch.  The flow table entries that it displays are not
              OpenFlow flow entries.  Instead, they are different and
              considerably simpler flows maintained by the datapath
              module.  If you wish to see the OpenFlow flow entries, use
              ovs-ofctl dump-flows.

       dpif/del-flows dp
              Deletes all flow entries from datapath dp's flow table and
              underlying datapath implementation (e.g., kernel datapath
              module).

              This command is primarily useful for debugging Open
              vSwitch.  As discussed in dpif/dump-flows, these entries
              are not OpenFlow flow entries.

   OFPROTO COMMANDS
       These commands manage the core OpenFlow switch implementation
       (called ofproto).

       ofproto/list
              Lists the names of the running ofproto instances.  These
              are the names that may be used on ofproto/trace.

       ofproto/trace [options] [dpname] odp_flow [packet]
       ofproto/trace [options] bridge br_flow [packet]]
       ofproto/trace-packet-out [options] [dpname] odp_flow [packet]
       actions
       ofproto/trace-packet-out [options] bridge br_flow [packet]
       actions
              Traces the path of an imaginary packet through switch and
              reports the path that it took.  The initial treatment of
              the packet varies based on the command:

              •      ofproto/trace looks the packet up in the OpenFlow
                     flow table, as if the packet had arrived on an
                     OpenFlow port.

              •      ofproto/trace-packet-out applies the specified
                     OpenFlow actions, as if the packet, flow, and
                     actions had been specified in an OpenFlow ``packet-
                     out'' request.

              The packet's headers (e.g. source and destination) and
              metadata (e.g. input port), together called its ``flow,''
              are usually all that matter for the purpose of tracing a
              packet.  You can specify the flow in the following ways:

              dpname odp_flow
                     odp_flow is a flow in the form printed by
                     ovs-dpctl(8)'s dump-flows command.  If all of your
                     bridges have the same type, which is the common
                     case, then you can omit dpname, but if you have
                     bridges of different types (say, both ovs-netdev
                     and ovs-system), then you need to specify a dpname
                     to disambiguate.

              bridge br_flow
                     br_flow 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.)  bridge names of the
                     bridge through which br_flow should be traced.

              These commands support the following options:

              --generate
                     Generate a packet from the flow (see below for more
                     information).

              --l7 payload
              --l7-len length
                     Accepted only with --generate (see below for more
                     information).

              --consistent
                     Accepted by ofproto-trace-packet-out only.  With
                     this option, the command rejects actions that are
                     inconsistent with the specified packet.  (An
                     example of an inconsistency is attempting to strip
                     the VLAN tag from a packet that does not have a
                     VLAN tag.)  Open vSwitch ignores most forms of
                     inconsistency in OpenFlow 1.0 and rejects
                     inconsistencies in later versions of OpenFlow.  The
                     option is necessary because the command does not
                     ordinarily imply a particular OpenFlow version.
                     One exception is that, when actions includes an
                     action that only OpenFlow 1.1 and later supports
                     (such as push_vlan), --consistent is automatically
                     enabled.

              --ct-next flags
                     When the traced flow triggers conntrack actions,
                     ofproto/trace will automatically trace the forked
                     packet processing pipeline with user specified
                     ct_state.  This option sets the ct_state flags that
                     the conntrack module will report. The flags must be
                     a comma- or space-separated list of the following
                     connection tracking flags:

                     •      trk: Include to indicate connection tracking
                            has taken place.

                     •      new: Include to indicate a new flow.

                     •      est: Include to indicate an established
                            flow.

                     •      rel: Include to indicate a related flow.

                     •      rpl: Include to indicate a reply flow.

                     •      inv: Include to indicate a connection entry
                            in a bad state.

                     •      dnat: Include to indicate a packet whose
                            destination IP address has been changed.

                     •      snat: Include to indicate a packet whose
                            source IP address has been changed.

                     When --ct-next is unspecified, or when there are
                     fewer --ct-next options than ct actions, the flags
                     default to trk,new.

              Most commonly, one specifies only a flow, using one of the
              forms above, but sometimes one might need to specify an
              actual packet instead of just a flow:

              Side effects.
                     Some actions have side effects.  For example, the
                     normal action can update the MAC learning table,
                     and the learn action can change OpenFlow tables.
                     The trace commands only perform side effects when a
                     packet is specified.  If you want side effects to
                     take place, then you must supply a packet.

                     (Output actions are obviously side effects too, but
                     the trace commands never execute them, even when
                     one specifies a packet.)

              Incomplete information.
                     Most of the time, Open vSwitch can figure out
                     everything about the path of a packet using just
                     the flow, but in some special circumstances it
                     needs to look at parts of the packet that are not
                     included in the flow.  When this is the case, and
                     you do not supply a packet, then a trace command
                     will tell you it needs a packet.

              If you wish to include a packet as part of a trace
              operation, there are two ways to do it:

              --generate
                     This option, added to one of the ways to specify a
                     flow already described, causes Open vSwitch to
                     internally generate a packet with the flow
                     described and then to use that packet.  If your
                     goal is to execute side effects, then --generate is
                     the easiest way to do it, but --generate is not a
                     good way to fill in incomplete information, because
                     it generates packets based on only the flow
                     information, which means that the packets really do
                     not have any more information than the flow.

                     By default, for protocols that allow arbitrary L7
                     payloads, the generated packet has 64 bytes of
                     payload.  Use --l7-len to change the payload
                     length, or --l7 to specify the exact contents of
                     the payload.

              packet This form supplies an explicit packet as a sequence
                     of hex digits.  An Ethernet frame is at least 14
                     bytes long, so there must be at least 28 hex
                     digits.  Obviously, it is inconvenient to type in
                     the hex digits by hand, so the ovs-pcap(1) and
                     ovs-tcpundump(1) utilities provide easier ways.

                     With this form, packet headers are extracted
                     directly from packet, so the odp_flow or br_flow
                     should specify only metadata. The metadata can be:

                     skb_priority
                            Packet QoS priority.

                     pkt_mark
                            Mark of the packet.

                     ct_state
                            Connection state of the packet.

                     ct_zone
                            Connection tracking zone for packet.

                     ct_mark
                            Connection mark of the packet.

                     ct_label
                            Connection label of the packet.

                     tun_id The tunnel ID on which the packet arrived.

                     in_port
                            The port on which the packet arrived.

              The in_port value is kernel datapath port number for the
              first format and OpenFlow port number for the second
              format. The numbering of these two types of port usually
              differs and there is no relationship.

       Usage examples:

           Trace an unicast ICMP echo request on ingress port 1 to
           destination MAC 00:00:5E:00:53:01
               ofproto/trace br in_port=1,icmp,icmp_type=8,\
               dl_dst=00:00:5E:00:53:01

           Trace an unicast ICMP echo reply on ingress port 1 to
           destination MAC 00:00:5E:00:53:01
               ofproto/trace br in_port=1,icmp,icmp_type=0,\
               dl_dst=00:00:5E:00:53:01

           Trace an ARP request on ingress port 1
               ofproto/trace br in_port=1,arp,arp_op=1

           Trace an ARP reply on ingress port 1
               ofproto/trace br in_port=1,arp,arp_op=2

   VLOG COMMANDS
       These commands manage ovs-vswitchd's logging settings.

       vlog/set [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.

                     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 ovs-vswitchd was invoked
              with the --log-file option.

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

       vlog/set 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.

       vlog/list
              Lists the supported logging modules and their current
              levels.

       vlog/list-pattern
              Lists logging patterns used for each destination.

       vlog/close
              Causes ovs-vswitchd to close its log file, if it is open.
              (Use vlog/reopen to reopen it later.)

       vlog/reopen
              Causes ovs-vswitchd to close its log file, if it is open,
              and then reopen it.  (This is useful after rotating log
              files, to cause a new log file to be used.)

              This has no effect unless ovs-vswitchd was invoked with
              the --log-file option.

       vlog/disable-rate-limit [module]...
       vlog/enable-rate-limit [module]...
              By default, ovs-vswitchd limits the rate at which certain
              messages can be logged.  When a message would appear more
              frequently than the limit, it is suppressed.  This saves
              disk space, makes logs easier to read, and speeds up
              execution, but occasionally troubleshooting requires more
              detail.  Therefore, vlog/disable-rate-limit allows rate
              limits to be disabled at the level of an individual log
              module.  Specify one or more module names, as displayed by
              the vlog/list command.  Specifying either no module names
              at all or the keyword any disables rate limits for every
              log module.

              The vlog/enable-rate-limit command, whose syntax is the
              same as vlog/disable-rate-limit, can be used to re-enable
              a rate limit that was previously disabled.

   MEMORY COMMANDS
       These commands report memory usage.

       memory/show
              Displays some basic statistics about ovs-vswitchd's memory
              usage.  ovs-vswitchd also logs this information soon after
              startup and periodically as its memory consumption grows.

   COVERAGE COMMANDS
       These commands manage ovs-vswitchd's ``coverage counters,'' which
       count the number of times particular events occur during a
       daemon's runtime.  In addition to these commands, ovs-vswitchd
       automatically logs coverage counter values, at INFO level, when
       it detects that the daemon's main loop takes unusually long to
       run.

       Coverage counters are useful mainly for performance analysis and
       debugging.

       coverage/show
              Displays the averaged per-second rates for the last few
              seconds, the last minute and the last hour, and the total
              counts of all of the coverage counters.

       coverage/read-counter counter
              Displays the total count for the given coverage counter.

   OPENVSWITCH TUNNELING COMMANDS
       These commands query and modify OVS tunnel components.

       ovs/route/add ipv4_address/plen output_bridge [GW]
              Adds ipv4_address/plen route to vswitchd routing table.
              output_bridge needs to be OVS bridge name.  This command
              is useful if OVS cached routes does not look right.

       ovs/route/show
              Print all routes in OVS routing table, This includes
              routes cached from system routing table and user
              configured routes.

       ovs/route/del ipv4_address/plen
              Delete ipv4_address/plen route from OVS routing table.

       tnl/neigh/show

       tnl/arp/show
              OVS builds ARP cache by snooping are messages. This
              command shows ARP cache table.

       tnl/neigh/set bridge ip mac

       tnl/arp/set bridge ip mac
              Adds or modifies an ARP cache entry in bridge, mapping ip
              to mac.

       tnl/neigh/flush

       tnl/arp/flush
              Flush ARP table.

       tnl/egress_port_range [num1] [num2]
              Set range for UDP source port used for UDP based Tunnels.
              For example VxLAN. If case of zero arguments this command
              prints current range in use.

OPENFLOW IMPLEMENTATION         top

       This section documents aspects of OpenFlow for which the OpenFlow
       specification requires documentation.

   Packet buffering.
       The OpenFlow specification, version 1.2, says:

              Switches that implement buffering are expected to expose,
              through documentation, both the amount of available
              buffering, and the length of time before buffers may be
              reused.

       Open vSwitch does not maintains any packet buffers.

   Bundle lifetime
       The OpenFlow specification, version 1.4, says:

              If the switch does not receive any OFPT_BUNDLE_CONTROL or
              OFPT_BUNDLE_ADD_MESSAGE message for an opened bundle_id
              for a switch defined time greater than 1s, it may send an
              ofp_error_msg with OFPET_BUNDLE_FAILED type and
              OFPBFC_TIMEOUT code.  If the switch does not receive any
              new message in a bundle apart from echo request and
              replies for a switch defined time greater than 1s, it may
              send an ofp_error_msg with OFPET_BUNDLE_FAILED type and
              OFPBFC_TIMEOUT code.

       Open vSwitch implements default idle bundle lifetime of 10
       seconds.  (This is configurable via other-config:bundle-idle-
       timeout in the Open_vSwitch table. See ovs-vswitchd.conf.db(5)
       for details.)

LIMITS         top

       We believe these limits to be accurate as of this writing.  These
       limits assume the use of the Linux kernel datapath.

       •      ovs-vswitchd started through ovs-ctl(8) provides a limit
              of 65535 file descriptors.  The limits on the number of
              bridges and ports is decided by the availability of file
              descriptors.  With the Linux kernel datapath, creation of
              a single bridge consumes three file descriptors and each
              port consumes one additional file descriptor.  Other
              platforms may have different limitations.

       •      8,192 MAC learning entries per bridge, by default.  (This
              is configurable via other-config:mac-table-size in the
              Bridge table.  See ovs-vswitchd.conf.db(5) for details.)

       •      Kernel flows are limited only by memory available to the
              kernel.  Performance will degrade beyond 1,048,576 kernel
              flows per bridge with a 32-bit kernel, beyond 262,144 with
              a 64-bit kernel.  (ovs-vswitchd should never install
              anywhere near that many flows.)

       •      OpenFlow flows are limited only by available memory.
              Performance is linear in the number of unique wildcard
              patterns.  That is, an OpenFlow table that contains many
              flows that all match on the same fields in the same way
              has a constant-time lookup, but a table that contains many
              flows that match on different fields requires lookup time
              linear in the number of flows.

       •      255 ports per bridge participating in 802.1D Spanning Tree
              Protocol.

       •      32 mirrors per bridge.

       •      15 bytes for the name of a port, for ports implemented in
              the Linux kernel.  Ports implemented in userspace, such as
              patch ports, do not have an arbitrary length limitation.
              OpenFlow also limit port names to 15 bytes.

SEE ALSO         top

       ovs-appctl(8), ovsdb-server(1).

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 2021-04-01.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-04-01.)  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                     2.15.90                 ovs-vswitchd(8)

Pages that refer to this page: ovs-pcap(1)ovs-tcpundump(1)ovn-architecture(7)ovn-controller(8)ovs-appctl(8)ovs-dpctl(8)ovs-l3ping(8)ovs-ofctl(8)ovs-tcpdump(8)ovs-vsctl(8)