ovn-ic - Man Page

Open Virtual Network interconnection controller



ovn-ic [options]


ovn-ic, OVN interconnection controller, is a centralized daemon which communicates with global interconnection databases IC_NB/IC_SB to configure and exchange data with local NB/SB for interconnecting with other OVN deployments.



The OVSDB database containing the OVN Northbound Database. If the OVN_NB_DB environment variable is set, its value is used as the default. Otherwise, the default is unix:/ovnnb_db.sock.


The OVSDB database containing the OVN Southbound Database. If the OVN_SB_DB environment variable is set, its value is used as the default. Otherwise, the default is unix:/ovnsb_db.sock.


The OVSDB database containing the OVN Interconnection Northbound Database. If the OVN_IC_NB_DB environment variable is set, its value is used as the default. Otherwise, the default is unix:/ovn_ic_nb_db.sock.


The OVSDB database containing the OVN Interconnection Southbound Database. If the OVN_IC_SB_DB environment variable is set, its value is used as the default. Otherwise, the default is unix:/ovn_ic_sb_db.sock.

database in the above options must be an OVSDB active or passive connection method, as described in ovsdb(7).

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 pidfile already exists and is locked by a running process, the daemon 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 (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIGPIPE, SIGSEGV, SIGXCPU, or SIGXFSZ) then the monitor process starts a new copy of it. If the daemon dies or exits for another reason, the monitor process exits.

This option is normally used with --detach, but it also functions without it.


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 chosen 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 whitelisted 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 additional 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 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, 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 --verbose=dbg.


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 /var/log/ovn/program.log.


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.


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 message 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 possible to specify arbitrary message format with this option. However, rsyslogd 8.9 and older versions use hard coded parser function anyway that limits UNIX domain socket use. If you want to use arbitrary message format with older rsyslogd versions, then use UDP socket to localhost IP address instead.
  • udp:ip:port, 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 example, syslog daemon needs to be configured to listen on the specified UDP port, accidental iptables rules could be interfering with local syslog traffic and there are some security considerations that apply to UDP sockets, but do not apply to UNIX domain sockets.
  • null, to discard all messages logged to syslog.

The default is taken from the OVS_SYSLOG_METHOD environment variable; 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 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

Specifies a PEM file containing the CA certificate for verifying 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 use.)

-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.

Other Options


Sets the name of the control socket on which program listens for runtime management commands (see Runtime Management Commands, below). If socket does not begin with /, it is interpreted as relative to . If --unixctl is not used at all, the default socket is /program.pid.ctl, where pid is program’s process ID.

On Windows a local named pipe is used to listen for runtime management commands. A file is created in the absolute path as pointed by socket or if --unixctl is not used at all, a file is created as program in the configured OVS_RUNDIR directory. The file exists just to mimic the behavior of a Unix domain socket.

Specifying none for socket disables the control socket feature.


Prints a brief help message to the console.


Prints version information to the console.

Runtime Management Commands

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


Causes ovn-ic to gracefully terminate.


Pauses the ovn-ic operation from processing any database changes. This will also instruct ovn-ic to drop any lock on SB DB.


Resumes the ovn-ic operation to process database contents. This will also instruct ovn-northd to aspire for the lock on SB DB.


Returns "true" if ovn-ic is currently paused, "false" otherwise.


Prints this server’s status. Status will be "active" if ovn-ic has acquired OVSDB lock on SB DB, "standby" if it has not or "paused" if this instance is paused.

Active-Standby for High Availability

You may run ovn-ic more than once in an OVN deployment. When connected to a standalone or clustered DB setup, OVN will automatically ensure that only one of them is active at a time. If multiple instances of ovn-ic are running and the active ovn-ic fails, one of the hot standby instances of ovn-ic will automatically take over.

Referenced By


OVN 20.03.0 OVN Manual