ovn-nbctl(8) OVN Manual ovn-nbctl(8) NAME ovn-nbctl - Open Virtual Network northbound db management utility SYNOPSIS ovn-nbctl [options] command [arg...] DESCRIPTION The ovn-nbctl program configures the OVN_Northbound database by provid‐ ing a high-level interface to its configuration database. See ovn-nb(5) for comprehensive documentation of the database schema. ovn-nbctl connects to an ovsdb-server process that maintains an OVN_Northbound configuration database. Using this connection, it queries and possibly applies changes to the database, depending on the supplied commands. ovn-nbctl can perform any number of commands in a single run, imple‐ mented as a single atomic transaction against the database. The ovn-nbctl command line begins with global options (see OPTIONS below for details). The global options are followed by one or more com‐ mands. Each command should begin with -- by itself as a command-line argument, to separate it from the following commands. (The -- before the first command is optional.) The command itself starts with command- specific options, if any, followed by the command name and any argu‐ ments. DAEMON MODE When it is invoked in the most ordinary way, ovn-nbctl connects to an OVSDB server that hosts the northbound database, retrieves a partial copy of the database that is complete enough to do its work, sends a transaction request to the server, and receives and processes the server’s reply. In common interactive use, this is fine, but if the database is large, the step in which ovn-nbctl retrieves a partial copy of the database can take a long time, which yields poor performance overall. To improve performance in such a case, ovn-nbctl offers a "daemon mode," in which the user first starts ovn-nbctl running in the back‐ ground and afterward uses the daemon to execute operations. Over sev‐ eral ovn-nbctl command invocations, this performs better overall because it retrieves a copy of the database only once at the beginning, not once per program run. Use the --detach option to start an ovn-nbctl daemon. With this option, ovn-nbctl prints the name of a control socket to stdout. The client should save this name in environment variable OVN_NB_DAEMON. Under the Bourne shell this might be done like this: export OVN_NB_DAEMON=$(ovn-nbctl --pidfile --detach) When OVN_NB_DAEMON is set, ovn-nbctl automatically and transparently uses the daemon to execute its commands. When the daemon is no longer needed, kill it and unset the environment variable, e.g.: kill $(cat $OVN_RUNDIR/ovn-nbctl.pid) unset OVN_NB_DAEMON When using daemon mode, an alternative to the OVN_NB_DAEMON environment variable is to specify a path for the Unix socket. When starting the ovn-nbctl daemon, specify the -u option with a full path to the loca‐ tion of the socket file. Here is an exmple: ovn-nbctl --detach -u /tmp/mysock.ctl Then to connect to the running daemon, use the -u option with the full path to the socket created when the daemon was started: ovn-nbctl -u /tmp/mysock.ctl show Daemon Commands Daemon mode is internally implemented using the same mechanism used by ovn-appctl. One may also use ovn-appctl directly with the following commands: run [options] command [arg...] [-- [options] command [arg...] ...] Instructs the daemon process to run one or more ovn-nbctl commands described above and reply with the results of running these commands. Accepts the --no-wait, --wait, --timeout, --dry-run, --oneline, and the options described under Table Formatting Options in addition to the the command-specific options. exit Causes ovn-nbctl to gracefully terminate. OPTIONS The options listed below affect the behavior of ovn-nbctl as a whole. Some individual commands also accept their own options, which are given just before the command name. If the first command on the command line has options, then those options must be separated from the global options by --. ovn-nbctl also accepts options from the OVN_NBCTL_OPTIONS environment variable, in the same format as on the command line. Options from the command line override those in the environment. --no-wait | --wait=none --wait=sb --wait=hv These options control whether and how ovn-nbctl waits for the OVN system to become up-to-date with changes made in an ovn-nbctl invocation. By default, or if --no-wait or --wait=none, ovn-nbctl exits immediately after confirming that changes have been commit‐ ted to the northbound database, without waiting. With --wait=sb, before ovn-nbctl exits, it waits for ovn-northd to bring the southbound database up-to-date with the northbound database updates. With --wait=hv, before ovn-nbctl exits, it additionally waits for all OVN chassis (hypervisors and gateways) to become up-to-date with the northbound database updates. (This can become an indefinite wait if any chassis is mal‐ functioning.) Ordinarily, --wait=sb or --wait=hv only waits for changes by the current ovn-nbctl invocation to take effect. This means that, if none of the commands supplied to ovn-nbctl change the database, then the command does not wait at all. Use the sync command to override this behavior. --db database The OVSDB database remote to contact. If the OVN_NB_DB environment variable is set, its value is used as the default. Otherwise, the default is unix:/ovnnb_db.sock, but this default is unlikely to be useful outside of single- machine OVN test environments. --leader-only --no-leader-only By default, or with --leader-only, when the database server is a clustered database, ovn-nbctl will avoid servers other than the cluster leader. This ensures that any data that ovn-nbctl reads and reports is up-to-date. With --no-leader-only, ovn-nbctl will use any server in the cluster, which means that for read-only transactions it can report and act on stale data (transactions that modify the database are always serialized even with --no-leader-only). Refer to Understanding Cluster Consistency in ovsdb(7) for more information. --shuffle-remotes --no-shuffle-remotes By default, or with --shuffle-remotes, when there are mul‐ tiple remotes specified in the OVSDB connection string specified by --db or the OVN_NB_DB environment variable, the order of the remotes will be shuffled before the client tries to connect. The remotes will be shuffled only once to a new order before the first connection attempt. The fol‐ lowing retries, if any, will follow the same new order. The default behavior is to make sure clients of a clustered database can distribute evenly to all memembers of the cluster. With --no-shuffle-remotes, ovn-nbctl will use the original order specified in the connection string to con‐ nect. This allows user to specify the preferred order, which is particularly useful for testing. --no-syslog By default, ovn-nbctl logs its arguments and the details of any changes that it makes to the system log. This option disables this logging. This option is equivalent to --verbose=nbctl:syslog:warn. --oneline Modifies the output format so that the output for each com‐ mand is printed on a single line. New-line characters that would otherwise separate lines are printed as \fB\\n\fR, and any instances of \fB\\\fR that would otherwise appear in the output are doubled. Prints a blank line for each command that has no output. This option does not affect the formatting of output from the list or find commands; see Table Formatting Options below. --dry-run Prevents ovn-nbctl from actually modifying the database. -t secs --timeout=secs By default, or with a secs of 0, ovn-nbctl waits forever for a response from the database. This option limits run‐ time to approximately secs seconds. If the timeout expires, ovn-nbctl will exit with a SIGALRM signal. (A timeout would normally happen only if the database cannot be contacted, or if the system is overloaded.) --print-wait-time When --wait is specified, the option --print-wait-time can be used to print the time spent on waiting, depending on the value specified in --wait option. If --wait=sb is specified, it prints "ovn-northd delay before processing", which is the time between the Northbound DB update by the command and the moment when ovn-northd starts processing the update, and "ovn-northd completion", which is the time between the Northbound DB update and the moment when ovn-northd completes the Southbound DB updating success‐ fully. If --wait=hv is specified, in addition to the above information, it also prints "ovn-controller(s) completion", which is the time between the Northbound DB update and the moment when the slowest hypervisor finishes processing the update. Daemon Options --pidfile[=pidfile] 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. --overwrite-pidfile 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. --detach 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. --monitor Creates an additional process to monitor this program. If it dies due to a signal that indicates a programming error (SIGA‐ BRT, 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 func‐ tions without it. --no-chdir 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. --no-self-confinement 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. --user=user:group 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 -v[spec] --verbose=[spec] Sets logging levels. Without any spec, sets the log level for every module and destination to dbg. Otherwise, spec is a list of words separated by spaces or commas or colons, up to one from each category below: · A valid module name, as displayed by the vlog/list command on ovs-appctl(8), limits the log level change to the 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. -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/ovn/program.log. --syslog-target=host:port 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‐ name. --syslog-method=method 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. Table Formatting Options These options control the format of output from the list and find com‐ mands. -f format --format=format Sets the type of table formatting. The following types of format are available: table 2-D text tables with aligned columns. list (default) A list with one column per line and rows separated by a blank line. html HTML tables. csv Comma-separated values as defined in RFC 4180. json JSON format as defined in RFC 4627. The output is a sequence of JSON objects, each of which corresponds to one table. Each JSON object has the following members with the noted values: caption The table’s caption. This member is omitted if the table has no caption. headings An array with one element per table column. Each array element is a string giving the corresponding column’s heading. data An array with one element per table row. Each element is also an array with one element per table column. The elements of this second- level array are the cells that constitute the table. Cells that represent OVSDB data or data types are expressed in the format described in the OVSDB specification; other cells are simply expressed as text strings. -d format --data=format Sets the formatting for cells within output tables unless the table format is set to json, in which case json format‐ ting is always used when formatting cells. The following types of format are available: string (default) The simple format described in the Database Values section of ovs-vsctl(8). bare The simple format with punctuation stripped off: [] and {} are omitted around sets, maps, and empty col‐ umns, items within sets and maps are space-sepa‐ rated, and strings are never quoted. This format may be easier for scripts to parse. json The RFC 4627 JSON format as described above. --no-headings This option suppresses the heading row that otherwise appears in the first row of table output. --pretty By default, JSON in output is printed as compactly as pos‐ sible. This option causes JSON in output to be printed in a more readable fashion. Members of objects and elements of arrays are printed one per line, with indentation. This option does not affect JSON in tables, which is always printed compactly. --bare Equivalent to --format=list --data=bare --no-headings. PKI Options PKI configuration is required to use SSL for the connection to the database. -p privkey.pem --private-key=privkey.pem Specifies a PEM file containing the private key used as identity for outgoing SSL connections. -c cert.pem --certificate=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 --ca-cert=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 use.) -C none --ca-cert=none Disables verification of certificates presented by SSL peers. This introduces a security risk, because it means that certificates cannot be verified to be those of known trusted hosts. --bootstrap-ca-cert=cacert.pem When cacert.pem exists, this option has the same effect as -C or --ca-cert. If it does not exist, then 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‐ tificate. This option is mutually exclusive with -C and --ca-cert. Other Options -h --help Prints a brief help message to the console. -V --version Prints version information to the console. COMMANDS The following sections describe the commands that ovn-nbctl supports. General Commands init Initializes the database, if it is empty. If the database has already been initialized, this command has no effect. show [switch | router] Prints a brief overview of the database contents. If switch is provided, only records related to that logical switch are shown. If router is provided, only records related to that logical router are shown. Logical Switch Commands ls-add Creates a new, unnamed logical switch, which initially has no ports. The switch does not have a name, other commands must refer to this switch by its UUID. [--may-exist | --add-duplicate] ls-add switch Creates a new logical switch named switch, which initially has no ports. The OVN northbound database schema does not require logical switch names to be unique, but the whole point to the names is to provide an easy way for humans to refer to the switches, mak‐ ing duplicate names unhelpful. Thus, without any options, this command regards it as an error if switch is a duplicate name. With --may-exist, adding a duplicate name succeeds but does not create a new logical switch. With --add-duplicate, the command really creates a new logical switch with a duplicate name. It is an error to specify both options. If there are multiple logical switches with a duplicate name, configure the logical switches using the UUID instead of the switch name. [--if-exists] ls-del switch Deletes switch. It is an error if switch does not exist, unless --if-exists is specified. ls-list Lists all existing switches on standard output, one per line. ACL Commands These commands operates on ACL objects for a given entity. The entity can be either a logical switch or a port group. The entity can be spec‐ ified as uuid or name. The --type option can be used to specify the type of the entity, in case both a logical switch and a port groups exist with the same name specified for entity. type must be either switch or port-group. [--type={switch | port-group}] [--log] [--meter=meter] [--sever‐ ity=severity] [--name=name] [--label=label] [--may-exist] [--apply-after-lb] acl-add entity direction priority match ver‐ dict Adds the specified ACL to entity. direction must be either from-lport or to-lport. priority must be between 0 and 32767, inclusive. A full description of the fields are in ovn-nb(5). If --may-exist is specified, adding a duplicated ACL succeeds but the ACL is not really cre‐ ated. Without --may-exist, adding a duplicated ACL results in error. The --log option enables packet logging for the ACL. The options --severity and --name specify a severity and name, respectively, for log entries (and also enable log‐ ging). The severity must be one of alert, warning, notice, info, or debug. If a severity is not specified, the default is info. The --meter=meter option is used to rate-limit packet logging. The meter argument names a meter configured by meter-add. The --apply-after-lb option sets apply-after-lb=true in the options column of the ACL table. As the option name suggests, the ACL will be applied after the logical switch load balancer stage. [--type={switch | port-group}] acl-del entity [direction [prior‐ ity match]] Deletes ACLs from entity. If only entity is supplied, all the ACLs from the entity are deleted. If direction is also specified, then all the flows in that direction will be deleted from the entity. If all the fields are given, then a single flow that matches all the fields will be deleted. [--type={switch | port-group}] acl-list entity Lists the ACLs on entity. Logical Switch QoS Rule Commands [--may-exist] qos-add switch direction priority match [dscp=dscp] [rate=rate [burst=burst]] Adds QoS marking and metering rules to switch. direction must be either from-lport or to-lport. priority must be between 0 and 32767, inclusive. If dscp=dscp is specified, then matching packets will have DSCP marking applied. dscp must be between 0 and 63, inclusive. If rate=rate is specified then matching packets will have metering applied at rate kbps. If metering is configured, then burst=burst specifies the burst rate limit in kilobits. dscp and/or rate are required arguments. If --may-exist is specified, adding a duplicated QoS rule suc‐ ceeds but the QoS rule is not really created. Without --may-exist, adding a duplicated QoS rule results in error. qos-del switch [direction [priority match]] Deletes QoS rules from switch. If only switch is supplied, all the QoS rules from the logical switch are deleted. If direction is also specified, then all the flows in that direction will be deleted from the logical switch. If all the fields are supplied, then a single flow that matches the given fields will be deleted. If switch and uuid are supplied, then the QoS rule with sepci‐ fied uuid is deleted. qos-list switch Lists the QoS rules on switch. Meter Commands meter-add name action rate unit [burst] Adds the specified meter. name must be a unique name to identify this meter. The action argument specifies what should happen when this meter is exceeded. The only supported action is drop. The unit specifies the unit for the rate argument; valid values are kbps and pktps for kilobits per second and packets per sec‐ ond, respectively. The burst option configures the maximum burst allowed for the band in kilobits or packets depending on whether the unit chosen was kbps or pktps, respectively. If a burst is not supplied, the switch is free to select some reasonable value depending on its configuration. ovn-nbctl only supports adding a meter with a single band, but the other commands support meters with multiple bands. Names that start with "__" (two underscores) are reserved for internal use by OVN, so ovn-nbctl does not allow adding them. meter-del [name] Deletes meters. By default, all meters are deleted. If name is supplied, only the meter with that name will be deleted. meter-list Lists all meters. Logical Switch Port Commands [--may-exist] lsp-add switch port Creates on lswitch a new logical switch port named port. It is an error if a logical port named port already exists, unless --may-exist is specified. Regardless of --may-exist, it is an error if the existing port is in some logical switch other than switch or if it has a parent port. [--may-exist] lsp-add switch port parent tag_request Creates on switch a logical switch port named port that is a child of parent that is identified with VLAN ID tag_request, which must be between 0 and 4095, inclusive. If tag_request is 0, ovn-northd generates a tag that is unique in the scope of parent. This is useful in cases such as virtualized container environments where Open vSwitch does not have a direct connec‐ tion to the container’s port and it must be shared with the vir‐ tual machine’s port. It is an error if a logical port named port already exists, unless --may-exist is specified. Regardless of --may-exist, it is an error if the existing port is not in switch or if it does not have the specified parent and tag_request. [--if-exists] lsp-del port Deletes port. It is an error if port does not exist, unless --if-exists is specified. lsp-list switch Lists all the logical switch ports within switch on standard output, one per line. lsp-get-parent port If set, get the parent port of port. If not set, print nothing. lsp-get-tag port If set, get the tag for port traffic. If not set, print nothing. lsp-set-addresses port [address]... Sets the addresses associated with port to address. Each address should be one of the following: an Ethernet address, optionally followed by a space and one or more IP addresses OVN delivers packets for the Ethernet address to this port. unknown OVN delivers unicast Ethernet packets whose destination MAC address is not in any logical port’s addresses column to ports with address unknown. dynamic Use this keyword to make ovn-northd generate a globally unique MAC address and choose an unused IPv4 address with the logical port’s subnet and store them in the port’s dynamic_addresses column. router Accepted only when the type of the logical switch port is router. This indicates that the Ethernet, IPv4, and IPv6 addresses for this logical switch port should be obtained from the connected logical router port, as specified by router-port in lsp-set-options. Multiple addresses may be set. If no address argument is given, port will have no addresses associated with it. lsp-get-addresses port Lists all the addresses associated with port on standard output, one per line. lsp-set-port-security port [addrs]... Sets the port security addresses associated with port to addrs. Multiple sets of addresses may be set by using multiple addrs arguments. If no addrs argument is given, port will not have port security enabled. Port security limits the addresses from which a logical port may send packets and to which it may receive packets. See the ovn-nb(5) documentation for the port_security column in the Log‐ ical_Switch_Port table for details. lsp-get-port-security port Lists all the port security addresses associated with port on standard output, one per line. lsp-get-up port Prints the state of port, either up or down. lsp-set-enabled port state Set the administrative state of port, either enabled or dis‐ abled. When a port is disabled, no traffic is allowed into or out of the port. lsp-get-enabled port Prints the administrative state of port, either enabled or dis‐ abled. lsp-set-type port type Set the type for the logical port. The type must be one of the following: (empty string) A VM (or VIF) interface. router A connection to a logical router. localnet A connection to a locally accessible network from each ovn-controller instance. A logical switch can only have a single localnet port attached. This is used to model direct connectivity to an existing network. localport A connection to a local VIF. Traffic that arrives on a localport is never forwarded over a tunnel to another chassis. These ports are present on every chassis and have the same address in all of them. This is used to model connectivity to local services that run on every hypervisor. l2gateway A connection to a physical network. vtep A port to a logical switch on a VTEP gateway. lsp-get-type port Get the type for the logical port. lsp-set-options port [key=value]... Set type-specific key-value options for the logical port. lsp-get-options port Get the type-specific options for the logical port. lsp-set-dhcpv4-options port dhcp_options Set the DHCPv4 options for the logical port. The dhcp_options is a UUID referring to a set of DHCP options in the DHCP_Options table. lsp-get-dhcpv4-options port Get the configured DHCPv4 options for the logical port. lsp-set-dhcpv6-options port dhcp_options Set the DHCPv6 options for the logical port. The dhcp_options is a UUID referring to a set of DHCP options in the DHCP_Options table. lsp-get-dhcpv6-options port Get the configured DHCPv6 options for the logical port. lsp-get-ls port Get the logical switch which the port belongs to. Forwarding Group Commands [--liveness]fwd-group-add group switch vip vmac ports Creates a new forwarding group named group as the name with the provided vip and vmac. vip should be a virtual IP address and vmac should be a virtual MAC address to access the forwarding group. ports are the logical switch port names that are put in the forwarding group. Example for ports is lsp1 lsp2 ... Traffic destined to virtual IP of the forwarding group will be load bal‐ anced to all the child ports. When --liveness is specified then child ports are expected to be bound to external devices like routers. BFD should be configured between hypervisors and the external devices. The child port selection will become dependent on BFD status with its external device. [--if-exists] fwd-group-del group Deletes group. It is an error if group does not exist, unless --if-exists is specified. fwd-group-list [switch] Lists all existing forwarding groups, If switch is specified then only the forwarding groups configured for switch will be listed. Logical Router Commands lr-add Creates a new, unnamed logical router, which initially has no ports. The router does not have a name, other commands must refer to this router by its UUID. [--may-exist | --add-duplicate] lr-add router Creates a new logical router named router, which initially has no ports. The OVN northbound database schema does not require logical router names to be unique, but the whole point to the names is to provide an easy way for humans to refer to the routers, mak‐ ing duplicate names unhelpful. Thus, without any options, this command regards it as an error if router is a duplicate name. With --may-exist, adding a duplicate name succeeds but does not create a new logical router. With --add-duplicate, the command really creates a new logical router with a duplicate name. It is an error to specify both options. If there are multiple logical routers with a duplicate name, configure the logical routers using the UUID instead of the router name. [--if-exists] lr-del router Deletes router. It is an error if router does not exist, unless --if-exists is specified. lr-list Lists all existing routers on standard output, one per line. Logical Router Port Commands [--may-exist] lrp-add router port mac network... [peer=peer] Creates on router a new logical router port named port with Eth‐ ernet address mac and one or more IP address/netmask for each network. The optional argument peer identifies a logical router port that connects to this one. The following example adds a router port with an IPv4 and IPv6 address with peer lr1: lrp-add lr0 lrp0 00:11:22:33:44:55 192.168.0.1/24 2001:db8::1/64 peer=lr1 It is an error if a logical router port named port already exists, unless --may-exist is specified. Regardless of --may-exist, it is an error if the existing router port is in some logical router other than router. [--if-exists] lrp-del port Deletes port. It is an error if port does not exist, unless --if-exists is specified. lrp-list router Lists all the logical router ports within router on standard output, one per line. lrp-set-enabled port state Set the administrative state of port, either enabled or dis‐ abled. When a port is disabled, no traffic is allowed into or out of the port. lrp-get-enabled port Prints the administrative state of port, either enabled or dis‐ abled. lrp-set-gateway-chassis port chassis [priority] Set gateway chassis for port. chassis is the name of the chas‐ sis. This creates a gateway chassis entry in Gateway_Chassis ta‐ ble. It won’t check if chassis really exists in OVN_Southbound database. Priority will be set to 0 if priority is not provided by user. priority must be between 0 and 32767, inclusive. lrp-del-gateway-chassis port chassis Deletes gateway chassis from port. It is an error if gateway chassis with chassis for port does not exist. lrp-get-gateway-chassis port Lists all the gateway chassis with priority within port on stan‐ dard output, one per line, ordered based on priority. Logical Router Static Route Commands [--may-exist] [--policy=POLICY] [--ecmp] [--ecmp-symmetric-reply] [--bfd[=UUID]] lr-route-add router prefix nexthop [port] Adds the specified route to router. prefix describes an IPv4 or IPv6 prefix for this route, such as 192.168.100.0/24. nexthop specifies the gateway to use for this route, which should be the IP address of one of router logical router ports or the IP address of a logical port. If port is specified, packets that match this route will be sent out that port. When port is omit‐ ted, OVN infers the output port based on nexthop. Nexthop can be set to discard for dropping packets which match the given route. --policy describes the policy used to make routing decisions. This should be one of "dst-ip" or "src-ip". If not specified, the default is "dst-ip". The --ecmp option allows for multiple routes with the same pre‐ fix POLICY but different nexthop and port to be added. The --ecmp-symmetric-reply option makes it so that traffic that arrives over an ECMP route will have its reply traffic sent out over that same route. Setting --ecmp-symmetric-reply implies --ecmp so it is not necessary to set both. --bfd option is used to link a BFD session to the OVN route. If the BFD session UUID is provided, it will be used for the OVN route otherwise the next-hop will be used to perform a lookup in the OVN BFD table. If the lookup fails and port is specified, a new entry in the BFD table will be created using the nexthop as dst_ip and port as logical_port. It is an error if a route with prefix and POLICY already exists, unless --may-exist, --ecmp, or --ecmp-symmetric-reply is speci‐ fied. If --may-exist is specified but not --ecmp or --ecmp-sym‐ metric-reply, the existed route will be updated with the new nexthop and port. If --ecmp or --ecmp-symmetric-reply is speci‐ fied, a new route will be added, regardless of the existed route., which is useful when adding ECMP routes, i.e. routes with same POLICY and prefix but different nexthop and port. [--if-exists] [--policy=POLICY] lr-route-del router [prefix [nexthop [port]]] Deletes routes from router. If only router is supplied, all the routes from the logical router are deleted. If POLICY, prefix, nexthop and/or port are also specified, then all the routes that match the conditions will be deleted from the logical router. It is an error if there is no matching route entry, unless --if-exists is specified. lr-route-list router Lists the routes on router. Logical Router Policy Commands [--may-exist]lr-policy-add router priority match action [nexthop[,nex‐ thop,...]] [options key=value]] Add Policy to router which provides a way to configure per‐ mit/deny and reroute policies on the router. Permit/deny poli‐ cies are similar to OVN ACLs, but exist on the logical-router. Reroute policies are needed for service-insertion and service- chaining. nexthop is an optional parameter. It needs to be pro‐ vided only when action is reroute. Multiple nexthops can be specified for ECMP routing. A policy is uniquely identified by priority and match. Multiple policies can have the same prior‐ ity. options sets the router policy options as key-value pair. The supported option is : pkt_mark. If --may-exist is specified, adding a duplicated routing policy with the same priority and match string is not really created. Without --may-exist, adding a duplicated routing policy results in error. The following example shows a policy to lr1, which will drop packets from192.168.100.0/24. lr-policy-add lr1 100 ip4.src == 192.168.100.0/24 drop. lr-policy-add lr1 100 ip4.src == 192.168.100.0/24 allow pkt_mark=100 . [--if-exists] lr-policy-del router [{priority | uuid} [match]] Deletes polices from router. If only router is supplied, all the polices from the logical router are deleted. If priority and/or match are also specified, then all the polices that match the conditions will be deleted from the logical router. If router and uuid are supplied, then the policy with sepcified uuid is deleted. It is an error if uuid does not exist, unless --if-exists is specified. lr-policy-list router Lists the polices on router. NAT Commands [--may-exist] [--stateless] [--gateway_port=GATEWAY_PORT] lr-nat-add router type external_ip logical_ip [logical_port external_mac] Adds the specified NAT to router. The type must be one of snat, dnat, or dnat_and_snat. The external_ip is an IPv4 address. The logical_ip is an IPv4 network (e.g 192.168.1.0/24) or an IPv4 address. The logical_port and external_mac are only accepted when router is a distributed router (rather than a gateway router) and type is dnat_and_snat. The logical_port is the name of an existing logical switch port where the logical_ip resides. The external_mac is an Ethernet address. When --stateless is specified then it implies that we will be not use connection tracker, i.e internal ip and external ip are 1:1 mapped. This implies that --stateless is applicable only to dnat_and_snat type NAT rules. An external ip with --stateless NAT cannot be shared with any other NAT rule. --gateway-port option allows specifying the distributed gateway port of router where the NAT rule needs to be applied. GATE‐ WAY_PORT should reference a Logical_Router_Port row that is a distributed gateway port of router. When router has multiple distributed gateway ports, it is an error to not specify the GATEWAY_PORT. When type is dnat, the externally visible IP address external_ip is DNATted to the IP address logical_ip in the logical space. When type is snat, IP packets with their source IP address that either matches the IP address in logical_ip or is in the network provided by logical_ip is SNATed into the IP address in exter‐ nal_ip. When type is dnat_and_snat, the externally visible IP address external_ip is DNATted to the IP address logical_ip in the logi‐ cal space. In addition, IP packets with the source IP address that matches logical_ip is SNATed into the IP address in exter‐ nal_ip. When the logical_port and external_mac are specified, the NAT rule will be programmed on the chassis where the logical_port resides. This includes ARP replies for the external_ip, which return the value of external_mac. All packets transmitted with source IP address equal to external_ip will be sent using the external_mac. It is an error if a NAT already exists with the same values of router, type, external_ip, logical_ip and GATEWAY_PORT (in case of multiple distributed gateway ports), unless --may-exist is specified. When --may-exist, logical_port, and external_mac are all specified, the existing values of logical_port and exter‐ nal_mac are overwritten. [--if-exists] lr-nat-del router [type [ip] [gateway_port]] Deletes NATs from router. If only router is supplied, all the NATs from the logical router are deleted. If type is also speci‐ fied, then all the NATs that match the type will be deleted from the logical router. If ip is also specified without specifying gateway_port, then all the NATs that match the type and ip will be deleted from the logical router. If gateway_port is specified without specifying ip, then all the NATs that match the type and gateway_port will be deleted from the logical router. If all the fields are given, then a single NAT rule that matches all the fields will be deleted. When type is snat, the ip should be log‐ ical_ip. When type is dnat or dnat_and_snat, the ip shoud be external_ip. It is an error if both ip and gateway_port are specified and there is no matching NAT entry, unless --if-exists is specified. lr-nat-list router Lists the NATs on router. Load Balancer Commands [--may-exist | --add-duplicate | --reject | --event] lb-add lb vip ips [protocol] Creates a new load balancer named lb with the provided vip and ips or adds the vip to an existing lb. vip should be a virtual IP address (or an IP address and a port number with : as a sepa‐ rator). Examples for vip are 192.168.1.4, fd0f::1, and 192.168.1.5:8080. ips should be comma separated IP endpoints (or comma separated IP addresses and port numbers with : as a sepa‐ rator). ips must be the same address family as vip. Examples for ips are 10.0.0.1,10.0.0.2or [fdef::1]:8800,[fdef::2]:8800. The optional argument protocol must be either tcp, udp or sctp. This argument is useful when a port number is provided as part of the vip. If the protocol is unspecified and a port number is provided as part of the vip, OVN assumes the protocol to be tcp. It is an error if the vip already exists in the load balancer named lb, unless --may-exist is specified. With --add-duplicate, the command really creates a new load balancer with a duplicate name. If the load balancer is created with --reject option and it has no active backends, a TCP reset segment (for tcp) or an ICMP port unreachable packet (for all other kind of traffic) will be sent whenever an incoming packet is received for this load-bal‐ ancer. Please note using --reject option will disable empty_lb SB controller event for this load balancer. If the load balancer is created with --event option and it has no active backends, whenever the lb receives traffic, the event is reported in the Controller_Event table in the SB db. Please note --event option can’t be specified with --reject one. The following example adds a load balancer. lb-add lb0 30.0.0.10:80 192.168.10.10:80,192.168.10.20:80,192.168.10.30:80 udp [--if-exists] lb-del lb [vip] Deletes lb or the vip from lb. If vip is supplied, only the vip will be deleted from the lb. If only the lb is supplied, the lb will be deleted. It is an error if vip does not already exist in lb, unless --if-exists is specified. lb-list [lb] Lists the LBs. If lb is also specified, then only the specified lb will be listed. [--may-exist] ls-lb-add switch lb Adds the specified lb to switch. It is an error if a load bal‐ ancer named lb already exists in the switch, unless --may-exist is specified. [--if-exists] ls-lb-del switch [lb] Removes lb from switch. If only switch is supplied, all the LBs from the logical switch are removed. If lb is also specified, then only the lb will be removed from the logical switch. It is an error if lb does not exist in the switch, unless --if-exists is specified. ls-lb-list switch Lists the LBs for the given switch. [--may-exist] lr-lb-add router lb Adds the specified lb to router. It is an error if a load bal‐ ancer named lb already exists in the router, unless --may-exist is specified. [--if-exists] lr-lb-del router [lb] Removes lb from router. If only router is supplied, all the LBs from the logical router are removed. If lb is also specified, then only the lb will be removed from the logical router. It is an error if lb does not exist in the router, unless --if-exists is specified. lr-lb-list router Lists the LBs for the given router. DHCP Options commands dhcp-options-create cidr [key=value] Creates a new DHCP Options entry in the DHCP_Options table with the specified cidr and optional external-ids. dhcp-options-list Lists the DHCP Options entries. dhcp-options-del dhcp-option Deletes the DHCP Options entry referred by dhcp-option UUID. dhcp-options-set-options dhcp-option [key=value]... Set the DHCP Options for the dhcp-option UUID. dhcp-options-get-options dhcp-option Lists the DHCP Options for the dhcp-option UUID. Port Group commands pg-add group [port]... Creates a new port group in the Port_Group table named group with optional ports added to the group. pg-set-ports group port... Sets ports on the port group named group. It is an error if group does not exist. pg-del group Deletes port group group. It is an error if group does not exist. HA Chassis Group commands ha-chassis-group-add group Creates a new HA chassis group in the HA_Chassis_Group table named group. ha-chassis-group-del group Deletes the HA chassis group group. It is an error if group does not exist. ha-chassis-group-list Lists the HA chassis group group along with the HA chassis if any associated with it. ha-chassis-group-add-chassis group chassis priority Adds a new HA chassis chassis to the HA Chassis group group with the specified priority. If the chassis already exists, then the priority is updated. The chassis should be the name of the chas‐ sis in the OVN_Southbound. ha-chassis-group-remove-chassis group chassis Removes the HA chassis chassis from the HA chassis group group. It is an error if chassis does not exist. Control Plane Protection Policy commands These commands manage meters configured in Copp table linking them to logical datapaths through copp column in Logical_Switch or Logi‐ cal_Router tables. Protocol packets for which CoPP is enforced when sending packets to ovn-controller (if configured): · ARP · ND_NS · ND_NA · ND_RA · ND · DNS · IGMP · packets that require ARP resolution before forwarding · packets that require ND_NS before forwarding · packets that need to be replied to with ICMP Errors · packets that need to be replied to with TCP RST · packets that need to be replied to with DHCP_OPTS · packets that trigger a reject action · packets that trigger a SCTP abort action · controller_events · BFD copp-add name proto meter Adds the control proto to meter mapping to the control plane protection policy name. If no policy exists yet, it creates one. If a mapping already existed for proto, this will overwrite it. copp-del name [proto] Removes the control proto mapping for the name control plane protection policy. If proto is not specified, the whole control plane protection policy is destroyed. copp-list name Display the current control plane protection policy for name. ls-copp-add name switch Adds the control plane protection policy name to the log‐ ical switch switch. lr-copp-add name router Adds the control plane protection policy name to the log‐ ical router router. Synchronization Commands sync Ordinarily, --wait=sb or --wait=hv only waits for changes by the current ovn-nbctl invocation to take effect. This means that, if none of the commands supplied to ovn-nbctl change the database, then the command does not wait at all. With the sync command, however, ovn-nbctl waits even for earlier changes to the data‐ base to propagate down to the southbound database or all of the OVN chassis, according to the argument to --wait. Remote Connectivity Commands These commands manipulate the connections column in the NB_Global table and rows in the Connection table. When ovsdb-server is configured to use the connections column for OVSDB connections, this allows the administrator to use ovn-nbctl to configure database connections. get-connection Prints the configured connection(s). del-connection Deletes the configured connection(s). [--inactivity-probe=msecs] set-connection target... Sets the configured manager target or targets. Use --inactivity-probe=msecs to override the default idle connection inactivity probe time. Use 0 to disable inac‐ tivity probes. SSL Configuration Commands get-ssl Prints the SSL configuration. del-ssl Deletes the current SSL configuration. [--bootstrap] set-ssl private-key certificate ca-cert [ssl-protocol- list [ssl-cipher-list]] Sets the SSL configuration. Database Commands These commands query and modify the contents of ovsdb tables. They are a slight abstraction of the ovsdb interface and as such they operate at a lower level than other ovn-nbctl commands. Identifying Tables, Records, and Columns Each of these commands has a table parameter to identify a table within the database. Many of them also take a record parameter that identifies a particular record within a table. The record parameter may be the UUID for a record, which may be abbreviated to its first 4 (or more) hex digits, as long as that is unique. Many tables offer additional ways to identify records. Some commands also take column parameters that identify a particular field within the records in a table. For a list of tables and their columns, see ovn-nb(5) or see the table listing from the --help option. Record names must be specified in full and with correct capitalization, except that UUIDs may be abbreviated to their first 4 (or more) hex digits, as long as that is unique within the table. Names of tables and columns are not case-sensitive, and - and _ are treated interchange‐ ably. Unique abbreviations of table and column names are acceptable, e.g. d or dhcp is sufficient to identify the DHCP_Options table. Database Values Each column in the database accepts a fixed type of data. The currently defined basic types, and their representations, are: integer A decimal integer in the range -2**63 to 2**63-1, inclu‐ sive. real A floating-point number. Boolean True or false, written true or false, respectively. string An arbitrary Unicode string, except that null bytes are not allowed. Quotes are optional for most strings that begin with an English letter or underscore and consist only of letters, underscores, hyphens, and periods. How‐ ever, true and false and strings that match the syntax of UUIDs (see below) must be enclosed in double quotes to distinguish them from other basic types. When double quotes are used, the syntax is that of strings in JSON, e.g. backslashes may be used to escape special charac‐ ters. The empty string must be represented as a pair of double quotes (""). UUID Either a universally unique identifier in the style of RFC 4122, e.g. f81d4fae-7dec-11d0-a765-00a0c91e6bf6, or an @name defined by a get or create command within the same ovs-vsctl invocation. Multiple values in a single column may be separated by spaces or a sin‐ gle comma. When multiple values are present, duplicates are not allowed, and order is not important. Conversely, some database columns can have an empty set of values, represented as [], and square brackets may optionally enclose other non-empty sets or single values as well. A few database columns are ``maps’’ of key-value pairs, where the key and the value are each some fixed database type. These are specified in the form key=value, where key and value follow the syntax for the col‐ umn’s key type and value type, respectively. When multiple pairs are present (separated by spaces or a comma), duplicate keys are not allowed, and again the order is not important. Duplicate values are allowed. An empty map is represented as {}. Curly braces may optionally enclose non-empty maps as well (but use quotes to prevent the shell from expanding other-config={0=x,1=y} into other-config=0=x other-con‐ fig=1=y, which may not have the desired effect). Database Command Syntax [--if-exists] [--columns=column[,column]...] list table [record]... Lists the data in each specified record. If no records are specified, lists all the records in table. If --columns is specified, only the requested columns are listed, in the specified order. Otherwise, all columns are listed, in alphabetical order by column name. Without --if-exists, it is an error if any specified record does not exist. With --if-exists, the command ignores any record that does not exist, without producing any output. [--columns=column[,column]...] find table [col‐ umn[:key]=value]... Lists the data in each record in table whose column equals value or, if key is specified, whose column con‐ tains a key with the specified value. The following oper‐ ators may be used where = is written in the syntax sum‐ mary: = != < > <= >= Selects records in which column[:key] equals, does not equal, is less than, is greater than, is less than or equal to, or is greater than or equal to value, respectively. Consider column[:key] and value as sets of ele‐ ments. Identical sets are considered equal. Other‐ wise, if the sets have different numbers of ele‐ ments, then the set with more elements is consid‐ ered to be larger. Otherwise, consider a element from each set pairwise, in increasing order within each set. The first pair that differs determines the result. (For a column that contains key-value pairs, first all the keys are compared, and values are considered only if the two sets contain iden‐ tical keys.) {=} {!=} Test for set equality or inequality, respectively. {<=} Selects records in which column[:key] is a subset of value. For example, flood-vlans{<=}1,2 selects records in which the flood-vlans column is the empty set or contains 1 or 2 or both. {<} Selects records in which column[:key] is a proper subset of value. For example, flood-vlans{<}1,2 selects records in which the flood-vlans column is the empty set or contains 1 or 2 but not both. {>=} {>} Same as {<=} and {<}, respectively, except that the relationship is reversed. For example, flood-vlans{>=}1,2 selects records in which the flood-vlans column contains both 1 and 2. The following operators are available only in Open vSwitch 2.16 and later: {in} Selects records in which every element in col‐ umn[:key] is also in value. (This is the same as {<=}.) {not-in} Selects records in which every element in col‐ umn[:key] is not in value. For arithmetic operators (= != < > <= >=), when key is specified but a particular record’s column does not con‐ tain key, the record is always omitted from the results. Thus, the condition other-config:mtu!=1500 matches records that have a mtu key whose value is not 1500, but not those that lack an mtu key. For the set operators, when key is specified but a par‐ ticular record’s column does not contain key, the compar‐ ison is done against an empty set. Thus, the condition other-config:mtu{!=}1500 matches records that have a mtu key whose value is not 1500 and those that lack an mtu key. Don’t forget to escape < or > from interpretation by the shell. If --columns is specified, only the requested columns are listed, in the specified order. Otherwise all columns are listed, in alphabetical order by column name. The UUIDs shown for rows created in the same ovs-vsctl invocation will be wrong. [--if-exists] [--id=@name] get table record [column[:key]]... Prints the value of each specified column in the given record in table. For map columns, a key may optionally be specified, in which case the value associated with key in the column is printed, instead of the entire map. Without --if-exists, it is an error if record does not exist or key is specified, if key does not exist in record. With --if-exists, a missing record yields no out‐ put and a missing key prints a blank line. If @name is specified, then the UUID for record may be referred to by that name later in the same ovs-vsctl invocation in contexts where a UUID is expected. Both --id and the column arguments are optional, but usu‐ ally at least one or the other should be specified. If both are omitted, then get has no effect except to verify that record exists in table. --id and --if-exists cannot be used together. [--if-exists] set table record column[:key]=value... Sets the value of each specified column in the given record in table to value. For map columns, a key may optionally be specified, in which case the value associ‐ ated with key in that column is changed (or added, if none exists), instead of the entire map. Without --if-exists, it is an error if record does not exist. With --if-exists, this command does nothing if record does not exist. [--if-exists] add table record column [key=]value... Adds the specified value or key-value pair to column in record in table. If column is a map, then key is required, otherwise it is prohibited. If key already exists in a map column, then the current value is not replaced (use the set command to replace an existing value). Without --if-exists, it is an error if record does not exist. With --if-exists, this command does nothing if record does not exist. [--if-exists] remove table record column value... [--if-exists] remove table record column key... [--if-exists] remove table record column key=value... Removes the specified values or key-value pairs from col‐ umn in record in table. The first form applies to columns that are not maps: each specified value is removed from the column. The second and third forms apply to map col‐ umns: if only a key is specified, then any key-value pair with the given key is removed, regardless of its value; if a value is given then a pair is removed only if both key and value match. It is not an error if the column does not contain the specified key or value or pair. Without --if-exists, it is an error if record does not exist. With --if-exists, this command does nothing if record does not exist. [--if-exists] clear table record column... Sets each column in record in table to the empty set or empty map, as appropriate. This command applies only to columns that are allowed to be empty. Without --if-exists, it is an error if record does not exist. With --if-exists, this command does nothing if record does not exist. [--id=@name] create table column[:key]=value... Creates a new record in table and sets the initial values of each column. Columns not explicitly set will receive their default values. Outputs the UUID of the new row. If @name is specified, then the UUID for the new row may be referred to by that name elsewhere in the same \*(PN invocation in contexts where a UUID is expected. Such references may precede or follow the create command. Caution (ovs-vsctl as example) Records in the Open vSwitch database are signifi‐ cant only when they can be reached directly or indirectly from the Open_vSwitch table. Except for records in the QoS or Queue tables, records that are not reachable from the Open_vSwitch table are automatically deleted from the database. This deletion happens immediately, without waiting for additional ovs-vsctl commands or other database activity. Thus, a create command must generally be accompanied by additional commands within the same ovs-vsctl invocation to add a chain of references to the newly created record from the top-level Open_vSwitch record. The EXAMPLES section gives some examples that show how to do this. [--if-exists] destroy table record... Deletes each specified record from table. Unless --if-exists is specified, each records must exist. --all destroy table Deletes all records from the table. Caution (ovs-vsctl as example) The destroy command is only useful for records in the QoS or Queue tables. Records in other tables are automatically deleted from the database when they become unreachable from the Open_vSwitch ta‐ ble. This means that deleting the last reference to a record is sufficient for deleting the record itself. For records in these tables, destroy is silently ignored. See the EXAMPLES section below for more information. wait-until table record [column[:key]=value]... Waits until table contains a record named record whose column equals value or, if key is specified, whose column contains a key with the specified value. This command supports the same operators and semantics described for the find command above. If no column[:key]=value arguments are given, this com‐ mand waits only until record exists. If more than one such argument is given, the command waits until all of them are satisfied. Caution (ovs-vsctl as example) Usually wait-until should be placed at the begin‐ ning of a set of ovs-vsctl commands. For example, wait-until bridge br0 -- get bridge br0 data‐ path_id waits until a bridge named br0 is created, then prints its datapath_id column, whereas get bridge br0 datapath_id -- wait-until bridge br0 will abort if no bridge named br0 exists when ovs-vsctl initially connects to the database. Consider specifying --timeout=0 along with --wait-until, to prevent ovs-vsctl from terminating after waiting only at most 5 seconds. comment [arg]... This command has no effect on behavior, but any database log record created by the command will include the com‐ mand and its arguments. ENVIRONMENT OVN_NB_DAEMON If set, this should name the Unix domain socket for an ovn-nbctl server process. See Daemon Mode, above, for more information. OVN_NBCTL_OPTIONS If set, a set of options for ovn-nbctl to apply automatically, in the same form as on the command line. OVN_NB_DB If set, the default database to contact when the --db option is not used. EXIT STATUS 0 Successful program execution. 1 Usage, syntax, or network error. SEE ALSO ovn-nb(5), ovn-appctl(8). OVN 22.06.2 ovn-nbctl ovn-nbctl(8)