Provided by: openvswitch-switch_3.3.0-1ubuntu3.1_amd64 bug

NAME

       ovs-vswitchd - Open vSwitch daemon

SYNOPSIS

       ovs-vswitchd [database]

DESCRIPTION

       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:/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

       --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).

   DPDK HW Access Options
       --hw-rawio-access
              Tells  ovs-vswitchd  to  retain the CAP_SYS_RAWIO capability, to allow userspace drivers access to
              raw hardware memory.  This will also allow the ovs-vswitchd daemon to  call  iopl()  and  ioperm()
              functions  as  well  as  access  memory  devices  to  set  port  access.   This is a very powerful
              capability, so generally only enable as needed for specific hardware (for example mlx5  with  full
              hardware offload via rte_flow).

   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 /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 /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 /var/run/openvswitch.  If --unixctl  is  not  used  at  all,  the  default  socket  is
              /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

       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/add bridge port vlan mac
              Adds  mac  address  to  a  port and vlan on a bridge. This utility can be used to pre-populate fdb
              table without relying on dynamic mac learning.

       fdb/del bridge vlan mac
              Deletes mac address from a port and vlan on a bridge.

       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 similar to that accepted by ovs-ofctl(8)'s add-flow command. (This  is  not  an  OpenFlow
              flow: besides other differences, it never contains wildcards.)  The filter is also useful to match
              wildcarded fields in the datapath flow. As an  example,  filter='tcp,tp_src=100'  will  match  the
              datapath flow containing '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.

   DATAPATH FLOW CACHE COMMANDS
       The following commands are useful for debugging and configuring the datapath flow cache settings.

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

       dpctl/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.

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

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

              If    ct-[orig|reply]-tuple   is   provided,   flushes   the   connection   entry   specified   by
              ct-[orig|reply]-tuple in zone.  The zone defaults to 0 if  it  is  not  provided.   The  userspace
              connection  tracker  requires flushing with the original pre-NATed tuple and a warning log will be
              otherwise generated.  The tuple can be partial and will remove all connections that  are  matching
              on  the  specified  fields.   In order to specify only ct-reply-tuple, provide empty string as ct-
              origin-tuple.

              Note: Currently there is a limitation for matching on ICMP, in order to partially  match  on  ICMP
              parameters the ct-[orig|reply]-tuple has to include either source or destination IP.

              An example of an IPv4 ICMP ct-[orig|reply]-tuple:

              "ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=1,icmp_type=8,icmp_code=0,icmp_id=10"

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

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

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

       dpctl/ct-get-sweep-interval [dp]
              Prints the current sweep interval in ms. 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/lcore-list
              Lists the DPDK lcores and their cpu affinity.  When RTE_MAX_LCORE lcores are registered, some  OVS
              PMD threads won't appear.

       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.

       dpdk/get-malloc-stats
              Prints the heap information statistics about DPDK malloc.

   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 "phwol hits", "simple match hits", "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.

              The  MFEX  Opt  hits  displays  the number of packets that are processed by the optimized miniflow
              extract implementations.

              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)
                       - PHWOL hits:                 0  (  0.0 %)
                       - MFEX Opt hits:        3570133  ( 99.2 %)
                       - Simple Match hits:          0  (  0.0 %)
                       - 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).

       dpif-netdev/subtable-lookup-prio-get
              Lists the DPCLS  implementations  or  lookup  functions  that  are  available  as  well  as  their
              priorities.

       dpif-netdev/subtable-lookup-prio-set lookup_function prio
              Sets  the priority of a lookup function by name, lookup_function, and priority, prio, which should
              be a positive integer value.  The highest priority lookup function is used for classification.

              The number of affected dpcls ports and subtables is returned.

       dpif-netdev/dpif-impl-get
              Lists the DPIF implementations that are available.

       dpif-netdev/dpif-impl-set dpif_impl
              Sets the DPIF to be used to dpif_impl. By default "dpif_scalar" is used.

       dpif-netdev/miniflow-parser-get
              Lists the miniflow extract implementations that are available.

       dpif-netdev/miniflow-parser-set [-pmd core] miniflow_impl [study_cnt]
              Sets the miniflow extract to miniflow_impl for a specified PMD or all PMDs in the  case  where  no
              value  is  specified.   By  default "scalar" is used.  study_cnt defaults to 128 and indicates the
              number of packets that the "study" miniflow implementation must parse before choosing  an  optimal
              implementation.

   DPIF-NETLINK COMMANDS
       These commands are used to expose internal information of the "dpif-netlink" kernel space datapath.

       dpif-netlink/dispatch-mode
              Displays the "dispatch-mode" for all datapaths.

   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.

   ODP-EXECUTE COMMANDS
       These commands manage the "odp-execute" component.

       odp-execute/action-impl-show
              Lists the actions implementations that are available and highlights the currently enabled one.

       odp-execute/action-impl-set action_impl
              Sets the action implementation to any available implementation. By default "scalar" is used.

   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 ip/plen output_bridge [gw] [pkt_mark=mark] [src=src_ip]
              Adds ip/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 ip/plen [pkt_mark=mark]
              Delete ip/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/neigh/aging [seconds]

       tnl/arp/aging [seconds]
              Changes the aging time. The accepted values of seconds are between 1 and  3600.  The  new  entries
              will  get  the  value as specified in seconds. For the existing entries, the aging time is updated
              only if the current expiration is greater than seconds.

              If used without arguments, it prints the current aging value.

       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

       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

       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

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