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



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.     The    default    is    unix:/usr/local/var/run/open
       vswitch/db.sock.  The following forms are accepted:

       ssl:ip:port
       tcp:ip:port
              The given SSL or plain TCP port on the host  at  the  given  ip,
              which  must  be  expressed  as an IP address (not a DNS name) in
              IPv4 or IPv6 address format.  If ip is  an  IPv6  address,  then
              wrap  ip  with square brackets, e.g.: ssl:[::1]:6640.  On Linux,
              use %device to designate a scope for IPv6 link-level  addresses,
              e.g.  ssl:[fe80::1234%eth0]:6653.   For  ssl, the --private-key,
              --certificate, and --ca-cert options are mandatory.

       unix:file
              On POSIX, connect to the Unix domain server socket named file.

              On Windows, connect to a local named pipe that is represented by
              a  file created in the path file to mimic the behavior of a Unix
              domain socket.

       pssl:port[:ip]
       ptcp:port[:ip]
              Listen on the given SSL  or  TCP  port  for  a  connection.   By
              default,  connections  are  not  bound  to a particular local IP
              address and it listens only on IPv4 (but  not  IPv6)  addresses,
              but specifying ip limits connections to those from the given ip,
              either IPv4 or IPv6 address.  If ip is  an  IPv6  address,  then
              wrap  ip with square brackets, e.g.: pssl:6640:[::1].  On Linux,
              use %device to designate a scope for IPv6 link-level  addresses,
              e.g.  pssl:6653:[fe80::1234%eth0].  For pssl, the --private-key,
              --certificate, and --ca-cert options are mandatory.

       punix:file
              On POSIX, listen on the Unix domain server socket named file for
              a connection.

              On  Windows, listen on a local named pipe.  A file is created in
              the path file to mimic the behavior of a Unix domain socket.

       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 fea‐
       tures:

       ·      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 data‐
       paths itself.  Thus, external tools, such ovs-dpctl(8), are not  needed
       for  managing datapaths in conjunction with ovs-vswitchd, and their use
       to modify datapaths when ovs-vswitchd is running can interfere with its
       operation.  (ovs-dpctl may still be 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 the ovs-vswitchd DPDK datapath, refer to
       the documentation or ovs-vswitchd.conf.db(5) for details.

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

       --pidfile[=pidfile]
              Causes a file (by default, ovs-vswitchd.pid) to be created indi‐
              cating  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 pid‐
              file  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 dae‐
              mon.  If the daemon dies due to a signal that indicates  a  pro‐
              gramming  error  (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIG
              PIPE, 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  func‐
              tions 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-know, at  build-time  whitelisted  directories.
              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 implemen‐
              tations 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  two  additional  capabilities, namely CAP_NET_ADMIN and
              CAP_NET_RAW. The capability change will apply even if  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 certifi‐
              cates 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 success‐
              ful, it will immediately drop the connection and reconnect,  and
              from then on all SSL connections must be authenticated by a cer‐
              tificate 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 use‐
              ful for bootstrapping.

              This option is only useful if the SSL peer sends its CA certifi‐
              cate  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.

   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 com‐
                     mand on ovs-appctl(8), limits the log level change to the
                     specified module.

              ·      syslog,  console,  or file, to limit the log level change
                     to only to the system log, to the console, or to a  file,
                     respectively.   (If  --detach  is specified, ovs-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  --ver
              bose=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/open
              vswitch/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 dae‐
              mon.  Following forms are supported:

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

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

              ·      udp:ip:port, use UDP socket.  With this method it is pos‐
                     sible  to  use  arbitrary  message format also with older
                     rsyslogd.  When sending syslog messages over  UDP  socket
                     extra  precaution  needs  to  be  taken into account, for
                     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 sock‐
                     ets, but do not apply to UNIX domain sockets.

   Other Options
       --unixctl=socket
              Sets the name of the control socket on which  ovs-vswitchd  lis‐
              tens  for  runtime  management  commands (see RUNTIME MANAGEMENT
              COMMANDS, below).  If socket does not begin with /, it is inter‐
              preted   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 man‐
              agement  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 direc‐
              tory.  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 descrip‐
       tions assume an understanding of how to configure Open vSwitch.

   GENERAL COMMANDS
       exit --cleanup
              Causes  ovs-vswitchd  to  gracefully  terminate. If --cleanup is
              specified,   release   datapath    resources    configured    by
              ovs-vswitchd.   Otherwise,  datapath  flows  and other resources
              remains undeleted.

       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 sta‐
              tistics associated with the given interface.

       bfd/show [interface]
              Displays detailed  information  about  Bidirectional  Forwarding
              Detection  configured  on interface.  If interface is not speci‐
              fied, 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  Manage‐
              ment  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.

       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 bridge
              Lists  all  flows  in bridge, including those normally hidden to
              commands such as ovs-ofctl dump-flows.  Flows set up  by  mecha‐
              nisms  such as in-band control and fail-open are hidden from the
              controller since it is not allowed to modify or override them.

   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
       slaves, 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 slave.

       bond/list
              Lists all of the bonds, and their slaves, 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 slave: 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  slave,  the  hashes  assigned  to  the
              slave.   Any  LACP information related to this bond may be found
              using the lacp/show command.

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

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

              A MAC hash cannot be migrated to a disabled slave.

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

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

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

              This setting is not permanent: it persists only until  the  car‐
              rier status of slave 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 prior‐
              ity.  Also lists information about each  slave:  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.

   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).

       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 moni‐
              tors,  where  dp is the name of an existing datapath, and netdev
              is the name of one of the host's  network  devices,  e.g.  eth0.
              Once a network device has been added to a datapath, the datapath
              has complete ownership of the network device's traffic  and  the
              network device appears silent to the rest of the system.

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

              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  automati‐
                     cally assigned.

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

              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 configu‐
              ration.

       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  data‐
              path  numbers  and  a  list of ports connected to each datapath.
              (The local port is identified as port 0.)  If -s or --statistics
              is specified, then packet and byte counters are also printed for
              each port.

              The datapath numbers consists of flow stats and mega  flow  mask
              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" dis‐
              plays the number of packets not matching any existing  flow  and
              require  user space processing.  "lost" displays number of pack‐
              ets destined for user space  process  but  subsequently  dropped
              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" dis‐
              plays the average number of masks visited per packet; the  ratio
              between "hit" and total number of packets processed by the data‐
              path.

              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 consid‐
       erably simpler flows maintained by the Open vSwitch kernel module.  Use
       ovs-ofctl(8), instead, to work with OpenFlow flow entries.

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

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

              If filter=filter is specified,  only  displays  the  flows  that
              match  the filter. filter is a flow in the form 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,   fil
              ter='tcp,tp_src=100' will match  the  datapath  flow  containing
              'tcp(src=80/0xff00,dst=8080/0xff)'.

              If  type=type  is  specified,  only displays flows of a specific
              type.  type can be offloaded to display only offloaded rules  or
              OVS  to  display only non-offloaded rules.  By default both off‐
              loaded and non-offloaded rules are displayed.

       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/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 DEBUGGING COMMANDS
       The  following  commands are primarily useful for debugging the connec‐
       tion tracking entries in the datapath.

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

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

       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 connec‐
              tions  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]
              Flushes all the connection entries in the tracker  used  by  dp.
              If zone=zone is specified, only flushes the connections in zone.

       dpctl/ct-stats-show [dp] [zone=zone] [verbose]
              Displays  the  number of connections grouped by protocol used by
              dp.  If zone=zone is specified, numbers refer to the connections
              in  zone. The verbose option allows to group by connection state
              for each protocol.

       dpctl/ct-bkts [dp] [gt=Threshold]
              For each ConnTracker 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.

   DPIF-NETDEV COMMANDS
       These  commands are used to expose internal information (mostly statis‐
       tics) 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.

       dpif-netdev/pmd-stats-show [dp]
              Shows performance statistics for each pmd thread of the datapath
              dp.  The special thread ``main'' sums up the statistics of every
              non pmd thread.  The sum of ``emc hits'',  ``masked  hits''  and
              ``miss''  is  the  number  of  packets received by the datapath.
              Cycles are counted using the TSC  or  similar  facilities  (when
              available  on  the platform).  To reset these counters use dpif-
              netdev/pmd-stats-clear. The duration of one cycle depends on the
              measuring infrastructure. ``idle cycles'' refers to cycles spent
              polling devices but  not  receiving  any  packets.  ``processing
              cycles'' refers to cycles spent polling devices and successfully
              receiving packets, plus the cycles spent processing  said  pack‐
              ets.

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

       dpif-netdev/pmd-rxq-show [dp]
              For each pmd thread of the datapath dp shows 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.

   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  com‐
       mands 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 ta‐
              ble. 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 mod‐
              ule).

              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 [dpname] odp_flow [OPTIONS] [-generate | packet]
       ofproto/trace bridge br_flow [OPTIONS] [-generate | packet]
       ofproto/trace-packet-out  [-consistent]  [dpname]  odp_flow   [OPTIONS]
       [-generate | packet] actions
       ofproto/trace-packet-out  [-consistent] bridge br_flow [OPTIONS] [-gen
       erate | 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 spec‐
              ify 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  Open‐
                     Flow  flow:  besides other differences, it never contains
                     wildcards.)  bridge names of  the  bridge  through  which
                     br_flow should be traced.

              ofproto/trace supports the following options:

              --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-sepa‐
                     rated 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  destina‐
                            tion 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  speci‐
                     fies 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 gen‐
                     erate  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.

              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 num‐
              bering of these two types of port usually differs and  there  is
              no relationship.

              ofproto-trace-packet-out   accepts   an  additional  -consistent
              option.  With this option specified, 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  incon‐
              sistencies  in later versions of OpenFlow.  The option is neces‐
              sary 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.

       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  com‐
                     mand on ovs-appctl(8), limits the log level change to the
                     specified module.

              ·      syslog, console, or file, to limit the log  level  change
                     to  only to the system log, to the console, or to a file,
                     respectively.

                     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  mes‐
              sages  can  be  logged.   When  a message would appear more fre‐
              quently 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 debug‐
       ging.

       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.

   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.  out‐
              put_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
       This section documents aspects of OpenFlow for which the OpenFlow spec‐
       ification 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  bun‐
              dle  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 idle bundle lifetime of 10 seconds.

LIMITS
       We  believe these limits to be accurate as of this writing.  These lim‐
       its 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 adding a  port  consumes  "n-handler-
              threads"  file  descriptors  per  bridge port.  Performance will
              degrade beyond 1,024 ports per bridge due to  fixed  hash  table
              sizing.  Other platforms may have different limitations.

       ·      2,048  MAC  learning  entries  per bridge, by default.  (This is
              configurable via other-config:mac-table-size in the  Bridge  ta‐
              ble.  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 ker‐
              nel.  (ovs-vswitchd should never install anywhere near that many
              flows.)

       ·      OpenFlow  flows  are  limited only by available memory.  Perfor‐
              mance 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  Pro‐
              tocol.

       ·      32 mirrors per bridge.

       ·      15  bytes for the name of a port.  (This is a Linux kernel limi‐
              tation.)

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



Open vSwitch                        2.8.90                     ovs-vswitchd(8)