ovn-controller(8)                 OVN Manual                 ovn-controller(8)

       ovn-controller - Open Virtual Network local controller

       ovn-controller [options] [ovs-database]

       ovn-controller is the local controller daemon for OVN, the Open Virtual
       Network. It connects up to the OVN Southbound database (see  ovn-sb(5))
       over  the  OVSDB  protocol,  and down to the Open vSwitch database (see
       ovs-vswitchd.conf.db(5)) over the OVSDB protocol and to ovs-vswitchd(8)
       via OpenFlow. Each hypervisor and software gateway in an OVN deployment
       runs its own independent copy of ovn-controller; thus, ovn-controller’s
       downward  connections  are machine-local and do not run over a physical

       ACL log messages are logged through ovn-controller’s logging mechanism.
       ACL  log entries have the module acl_log at log level info. Configuring
       logging is described below in the Logging Options section.

   Daemon Options
              Causes a file (by default, program.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

              If --pidfile is not specified, no pidfile is created.

              By  default,  when --pidfile is specified and the specified pid‐
              file already exists and is locked by a running process, the dae‐
              mon refuses to start. Specify --overwrite-pidfile to cause it to
              instead overwrite the pidfile.

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

              Runs this program 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.

              Creates  an  additional  process  to monitor this program. If it
              dies due to a signal that indicates a programming  error  (SIGA
              or SIGXFSZ) then the monitor process starts a new copy of it. If
              the daemon dies or exits for another reason, the monitor process

              This option is normally used with --detach, but  it  also  func‐
              tions without it.

              By  default,  when --detach is specified, the daemon changes its
              current  working  directory  to  the  root  directory  after  it
              detaches.  Otherwise, invoking the daemon from a carelessly cho‐
              sen directory would prevent the  administrator  from  unmounting
              the file system that holds that directory.

              Specifying  --no-chdir  suppresses this behavior, preventing the
              daemon 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.

              By  default  this daemon will try to self-confine itself to work
              with files under  well-known  directories  determined  at  build
              time.  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 addi‐
              tional layer of security.

              Causes this program 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  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.

   Logging Options
            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 speci‐
                   fied 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, the daemon  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.

            Sets the maximum logging verbosity  level,  equivalent  to  --ver

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

            Sets the RFC5424 facility of the log message. facility can be  one
            of kern, user, mail, daemon, auth, syslog, lpr, news, uucp, clock,
            ftp, ntp, audit, alert, clock2, local0,  local1,  local2,  local3,
            local4, local5, local6 or local7. If this option is not specified,
            daemon is used as the default for  the  local  system  syslog  and
            local0  is used while sending a message to the target provided via
            the --syslog-target option.

            Enables logging to a file. If file is specified, then it  is  used
            as the exact name for the log file. The default log file name used
            if file is omitted is /usr/local/var/log/ovn/program.log.

            Send syslog messages to UDP port on host, in addition to the  sys‐
            tem  syslog.  The host must be a numerical IP address, not a host‐

            Specify method as how syslog messages should  be  sent  to  syslog
            daemon. The following forms are supported:

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

            ·      unix:file, to use a UNIX domain socket directly. It is pos‐
                   sible 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, to use a 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 exam‐
                   ple, 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, to discard all messages logged to syslog.

            The default is taken from the OVS_SYSLOG_METHOD environment  vari‐
            able; if it is unset, the default is libc.

   PKI Options
       PKI  configuration  is required in order to use SSL for the connections
       to the Northbound and Southbound databases.

              -p privkey.pem
                   Specifies a PEM file containing the  private  key  used  as
                   identity for outgoing SSL connections.

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

              -C cacert.pem
                   Specifies a PEM file containing the CA certificate for ver‐
                   ifying certificates presented to this program 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

              -C 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.

                     When  cacert.pem  exists, this option has the same effect
                     as -C or --ca-cert. If it does not exist, then  the  exe‐
                     cutable  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 immedi‐
                     ately drop the connection and reconnect, and from then on
                     all  SSL  connections must be authenticated by a certifi‐
                     cate 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  cer‐

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

                     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 the program’s own cer‐
                     tificate, that is, the certificate  specified  on  -c  or
                     --certificate.  If  the  program’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 the program’s identity.
                     However, this offers a way  for  a  new  installation  to
                     bootstrap the CA certificate on its first SSL connection.

   Other Options
            Prints a brief help message to the console.

            Prints version information to the console.

       ovn-controller retrieves most of its configuration information from the
       local Open vSwitch’s ovsdb-server instance.  The  default  location  is
       db.sock in the local Open vSwitch’s "run" directory. It may be overrid‐
       den by specifying the ovs-database argument as an OVSDB active or  pas‐
       sive connection method, as described in ovsdb(7).

       ovn-controller  assumes it gets configuration information from the fol‐
       lowing keys in the Open_vSwitch table of the local OVS instance:

                     The chassis name to use in the  Chassis  table.  Changing
                     the  system-id  while  ovn-controller  is  running is not
                     directly supported. Users have two options: either  first
                     gracefully  stop  ovn-controller  or  manually delete the
                     stale Chassis and Chassis_Private records after  changing
                     the system-id.

                     The hostname to use in the Chassis table.

                     The   integration  bridge  to  which  logical  ports  are
                     attached. The default is br-int. If this bridge does  not
                     exist  when  ovn-controller  starts,  it  will be created
                     automatically with the default configuration suggested in

                     This configuration is optional. If set, then the datapath
                     type of the integration bridge will be set to the config‐
                     ured  value.  If  this  option  is not set, then ovn-con
                     troller will not modify the existing datapath-type of the
                     integration bridge.

                     The  OVN  database that this system should connect to for
                     its configuration, in one of the  same  forms  documented
                     above for the ovs-database.

                     A boolean value that tells if ovn-controller should moni‐
                     tor all records of tables  in  ovs-database.  If  set  to
                     false,  it will conditionally monitor the records that is
                     needed in the current chassis.

                     It is more optimal to set it to true in  use  cases  when
                     the  chassis  would  anyway  need  to monitor most of the
                     records in ovs-database, which would save the overhead of
                     conditions  processing, especially for server side. Typi‐
                     cally, set it to true for environments that all workloads
                     need to be reachable from each other.

                     Default value is false.

                     The  inactivity  probe  interval of the connection to the
                     OVN database, in milliseconds. If the value is  zero,  it
                     disables the connection keepalive feature.

                     If  the  value  is  nonzero,  then it will be forced to a
                     value of at least 1000 ms.

                     The inactivity probe interval of the OpenFlow  connection
                     to the OpenvSwitch integration bridge, in seconds. If the
                     value is zero, it disables the connection keepalive  fea‐

                     If  the  value  is  nonzero,  then it will be forced to a
                     value of at least 5s.

                     The encapsulation type that a chassis should use to  con‐
                     nect  to  this  node. Multiple encapsulation types may be
                     specified with a comma-separated list. Each listed encap‐
                     sulation type will be paired with ovn-encap-ip.

                     Supported  tunnel  types  for  connecting hypervisors are
                     geneve and stt. Gateways may use geneve, vxlan, or stt.

                     Due to the limited amount of metadata in vxlan, the capa‐
                     bilities  and  performance  of connected gateways will be
                     reduced versus other tunnel formats.

                     The IP address that a chassis should use  to  connect  to
                     this  node  using encapsulation types specified by exter

                     A list of key-value pairs that  map  a  physical  network
                     name  to a local ovs bridge that provides connectivity to
                     that network. An example value mapping two physical  net‐
                     work   names   to   two   ovs  bridges  would  be:  phys

                     ovn-encap-csum indicates that encapsulation checksums can
                     be  transmitted and received with reasonable performance.
                     It is a hint to senders transmitting data to this chassis
                     that  they  should use checksums to protect OVN metadata.
                     Set to true to enable or false to disable.  Depending  on
                     the  capabilities of the network interface card, enabling
                     encapsulation checksum may  incur  performance  loss.  In
                     such cases, encapsulation checksums can be disabled.

                     ovn-encap-tos  indicates  the  value to be applied to OVN
                     tunnel  interface’s  option:tos  as  specified   in   the
                     Open_vSwitch  database  Interface  table. Please refer to
                     Open VSwitch Manual for details.

                     A list of options that will be consumed by the CMS Plugin
                     and which specific to this particular chassis. An example
                     would be: cms_option1,cms_option2:foo.

                     The transport  zone(s)  that  this  chassis  belongs  to.
                     Transport  zones  is  a way to group different chassis so
                     that tunnels are only formed between members of the  same
                     group(s).  Multiple transport zones may be specified with
                     a comma-separated list. For example: tz1,tz2,tz3.

                     If not set, the Chassis will  be  considered  part  of  a
                     default transport zone.

                     A list of key-value pairs that map a chassis specific mac
                     to a physical network name. An example value mapping  two
                     chassis  macs  to  two  physical  network names would be:
                     These  are  the  macs  that ovn-controller will replace a
                     router port mac with, if packet is going from a  distrib‐
                     uted router port on vlan type logical switch.

                     The  boolean  flag indicates if the chassis is used as an
                     interconnection gateway.

                     The boolean flag indicates  if  ovn-controller  needs  to
                     check ovn-northd version. If this flag is set to true and
                     the ovn-northds  version  (reported  in  the  Southbound
                     database)  doesn’t match with the ovn-controllers inter‐
                     nal version, then it will stop processing the  southbound
                     and  local  Open  vSwitch  database  changes. The default
                     value is considered false if this option is not defined.

                     The  boolean  flag  indicates  if  ovn-controller  should
                     enable/disable  the  logical flow in-memory cache it uses
                     when processing Southbound database logical flow changes.
                     By default caching is enabled.

                     When  used, this configuration value determines the maxi‐
                     mum number of logical flow cache  entries  ovn-controller
                     may  create  when  the  logical flow cache is enabled. By
                     default the size of the cache is unlimited.

                     When used, this configuration value determines the  maxi‐
                     mum size of the logical flow cache (in KB) ovn-controller
                     may create when the logical flow  cache  is  enabled.  By
                     default the size of the cache is unlimited.

                     When used, this configuration value sets the minimum num‐
                     ber of entries in the logical flow  cache  starting  with
                     which  automatic memory trimming is performed. By default
                     this is set to 10000 entries.

                     When used, this configuration value sets  the  percentage
                     from  the high watermark number of entries in the logical
                     flow cache under which automatic memory trimming is  per‐
                     formed.  E.g., if the trim watermark percentage is set to
                     50%, automatic memory trimming happens only when the num‐
                     ber  of entries in the logical flow cache gets reduced to
                     less than half of the last measured  high  watermark.  By
                     default this is set to 50.

                     When  used,  this configuration value specifies the time,
                     in milliseconds, since the last logical flow cache opera‐
                     tion  after which ovn-controller performs memory trimming
                     regardless of how many entries there are in the cache. By
                     default this is set to 30000 (30 seconds).

                     The  boolean flag indicates if ovn-controller when create
                     tunnel ports should set local_ip parameter. Can be  hepl‐
                     ful  to  pin source outer IP for the tunnel when multiple
                     interfaces are used on the host for overlay traffic.

       ovn-controller reads the following values from the  Open_vSwitch  data‐
       base of the local OVS instance:

              datapath-type from Bridge table
                     This  value is read from local OVS integration bridge row
                     of Bridge table and populated  in  other_config:datapath-
                     type of the Chassis table in the OVN_Southbound database.

              iface-types from Open_vSwitch table
                     This  value  is  populated in external_ids:iface-types of
                     the Chassis table in the OVN_Southbound database.

              private_key, certificate, ca_cert,  and  bootstrap_ca_cert  from
              SSL table
                     These  values provide the SSL configuration used for con‐
                     necting to the OVN southbound database server when an SSL
                     connection     type     is    configured    via    exter
                     nal_ids:ovn-remote. Note that this SSL configuration  can
                     also be provided via command-line options, the configura‐
                     tion  in  the  database  takes  precedence  if  both  are

       ovn-controller  uses  a number of external_ids keys in the Open vSwitch
       database to keep track of ports and interfaces. For  proper  operation,
       users should not change or clear these keys:

              external_ids:ovn-chassis-id in the Port table
                     The  presence of this key identifies a tunnel port within
                     the integration bridge as one created  by  ovn-controller
                     to reach a remote chassis. Its value is the chassis ID of
                     the remote chassis.

              external_ids:ct-zone-* in the Bridge table
                     Logical ports and gateway routers are assigned a  connec‐
                     tion  tracking  zone  by ovn-controller for stateful ser‐
                     vices. To keep state across restarts  of  ovn-controller,
                     these  keys are stored in the integration bridge’s Bridge
                     table. The name contains a prefix of ct-zone- followed by
                     the  name  of  the  logical port or gateway router’s zone
                     key. The value for this key identifies the zone used  for
                     this port.

              external_ids:ovn-localnet-port in the Port table
                     The  presence  of this key identifies a patch port as one
                     created by  ovn-controller  to  connect  the  integration
                     bridge and another bridge to implement a localnet logical
                     port. Its value is the name of the logical port with type
                     set  to  localnet  that  the  port implements. See exter
                     nal_ids:ovn-bridge-mappings, above, for more information.

                     Each localnet logical port is implemented as  a  pair  of
                     patch ports, one in the integration bridge, one in a dif‐
                     ferent  bridge,  with  the  same  external_ids:ovn-local
                     net-port value.

              external_ids:ovn-l2gateway-port in the Port table
                     The  presence  of this key identifies a patch port as one
                     created by  ovn-controller  to  connect  the  integration
                     bridge  and another bridge to implement a l2gateway logi‐
                     cal port. Its value is the name of the logical port  with
                     type  set  to  l2gateway  that  the  port implements. See
                     external_ids:ovn-bridge-mappings, above, for more  infor‐

                     Each  l2gateway  logical port is implemented as a pair of
                     patch ports, one in the integration bridge, one in a dif‐
                     ferent  bridge,  with  the  same external_ids:ovn-l2gate
                     way-port value.

              external-ids:ovn-l3gateway-port in the Port table
                     This key identifies  a  patch  port  as  one  created  by
                     ovn-controller to implement a l3gateway logical port. Its
                     value is the name of the logical port with  type  set  to
                     l3gateway.  This patch port is similar to the OVN logical
                     patch port, except that l3gateway port can only be  bound
                     to a paticular chassis.

              external-ids:ovn-logical-patch-port in the Port table
                     This  key  identifies  a  patch  port  as  one created by
                     ovn-controller to implement an  OVN  logical  patch  port
                     within  the  integration bridge. Its value is the name of
                     the OVN logical patch port that it implements.

              external-ids:ovn-startup-ts in the Bridge table
                     This key represents the timestamp  (in  milliseconds)  at
                     which ovn-controller process was started.

              external-ids:ovn-nb-cfg in the Bridge table
                     This   key   represents   the   last   known   OVN_South
                     bound.SB_Global.nb_cfg value for  which  all  flows  have
                     been successfully installed in OVS.

              external-ids:ovn-nb-cfg-ts in the Bridge table
                     This  key  represents  the timestamp (in milliseconds) of
                     the last known OVN_Southbound.SB_Global.nb_cfg value  for
                     which all flows have been successfully installed in OVS.

              external_ids:ovn-installed  and external_ids:ovn-installed-ts in
              the Interface table
                     This key is set after all openflow operations correspond‐
                     ing  to  the  OVS  interface  have been processed by ovs-
                     vswitchd. At the same time a timestamp,  in  milliseconds
                     since     the     epoch,     is    stored    in    exter

       ovn-controller reads from much of the OVN_Southbound database to  guide
       its operation. ovn-controller also writes to the following tables:

                     Upon  startup, ovn-controller creates a row in this table
                     to represent its own chassis. Upon graceful  termination,
                     e.g.  with  ovs-appctl  -t  ovn-controller  exit (but not
                     SIGTERM), ovn-controller removes its row.

              Encap  Upon startup, ovn-controller creates a  row  or  rows  in
                     this  table  that  represent the tunnel encapsulations by
                     which its chassis can be reached, and points its  Chassis
                     row  to  them.  Upon graceful termination, ovn-controller
                     removes these rows.

                     At runtime, ovn-controller sets the  chassis  columns  of
                     ports  that  are  resident on its chassis to point to its
                     Chassis row, and, conversely, clears the  chassis  column
                     of  ports that point to its Chassis row but are no longer
                     resident on its chassis. The chassis column  has  a  weak
                     reference  type,  so when ovn-controller gracefully exits
                     and removes its Chassis row, the database server automat‐
                     ically clears any remaining references to that row.

                     At  runtime, ovn-controller updates the MAC_Binding table
                     as instructed by  put_arp  and  put_nd  logical  actions.
                     These  changes  persist  beyond  the lifetime of ovn-con

       ovs-appctl can send commands to a running ovn-controller  process.  The
       currently supported commands are described below.

              exit   Causes ovn-controller to gracefully terminate.

                     Lists each local logical port and its connection tracking

                     Lists each meter table entry and its local meter id.

                     Lists each group table entry and its local group id.

              inject-pkt microflow
                     Injects  microflow  into  the  connected   Open   vSwitch
                     instance.  microflow must contain an ingress logical port
                     (inport argument) that is present  on  the  Open  vSwitch

                     The  microflow  argument  describes the packet whose for‐
                     warding is to be simulated, in the syntax of an OVN logi‐
                     cal  expression,  as  described  in ovn-sb(5), to express
                     constraints. The parser  understands  prerequisites;  for
                     example, if the expression refers to ip4.src, there is no
                     need to explicitly state ip4 or eth.type == 0x800.

                     Show OVN SBDB connection status for the chassis.

                     Trigger a full compute iteration in ovn-controller  based
                     on  the contents of the Southbound database and local OVS

                     This command is intended to use only in the  event  of  a
                     bug  in  the  incremental  processing  engine in ovn-con
                     troller to avoid inconsistent states. It should therefore
                     be used with care as full recomputes are cpu intensive.

                     Reset  southbound  database cluster status when databases
                     are destroyed and rebuilt.

                     If all databases in a clustered southbound  database  are
                     removed from disk, then the stored index of all databases
                     will be reset to zero. This will cause ovn-controller  to
                     be  unable  to  read or write to the southbound database,
                     because it will always detect the data as stale. In  such
                     a  case,  run  this  command  so that ovn-controller will
                     reset its local index so that it can  interact  with  the
                     southbound database again.

              debug/delay-nb-cfg-report seconds
                     This command is used to delay ovn-controller updating the
                     nb_cfg back to OVN_Southbound database.  This  is  useful
                     when  ovn-nbctl  --wait=hv  is used to measure end-to-end
                     latency in a large scale  environment.  See  ovn-nbctl(8)
                     for more details.

                     Flushes the ovn-controller logical flow cache.

                     Displays logical flow cache statistics: enabled/disabled,
                     per cache type entry counts.

                     Display ovn-controller engine counters. For  each  engine
                     node the following counters have been added:

                     ·      recompute

                     ·      compute

                     ·      abort

                     Reset ovn-controller engine counters.

OVN 22.03.90                    ovn-controller               ovn-controller(8)