Provided by: ovn-common_20.03.2-0ubuntu0.20.04.6_amd64 bug

NAME

       ovn-nbctl - Open Virtual Network northbound db management utility

SYNOPSIS

       ovn-nbctl [options] command [arg...]

DESCRIPTION

       This utility can be used to manage the OVN northbound database.

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,  making
              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 specified 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] [--severity=severity] [--name=name]
              [--may-exist] acl-add entity direction priority match verdict
                     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
                     created. 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  logging).  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.

              [--type={switch | port-group}] acl-del entity [direction [priority 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 succeeds 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.

       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 second, 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 connection to the
              container’s port and it must be shared with the virtual 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
              Logical_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 disabled. 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 disabled.

       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 balanced 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, making
              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 Ethernet 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 disabled. 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 disabled.

       lrp-set-gateway-chassis port chassis [priority]
              Set gateway chassis for port. chassis is the name of the chassis. This creates a  gateway  chassis
              entry  in  Gateway_Chassis  table.  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 standard output, one per line,  ordered
              based on priority.

LOGICAL ROUTER STATIC ROUTE COMMANDS

       [--may-exist] [--policy=POLICY] [--ecmp] 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  omitted,  OVN
              infers the output port based on nexthop.

              --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".

              It is an error if a route with prefix and POLICY already exists, unless --may-exist or  --ecmp  is
              specified.  If --may-exist is specified but not --ecmp, the existed route will be updated with the
              new nexthop and port. If --ecmp is specified, 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.

NAT COMMANDS

       [--may-exist] [--stateless]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. The --stateless

              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.

              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
              external_ip.

              When type is dnat_and_snat, the externally visible IP address external_ip is  DNATted  to  the  IP
              address  logical_ip  in the logical space. In addition, IP packets with the source IP address that
              matches logical_ip is SNATed into the IP address in external_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, and
              logical_ip, unless --may-exist is specified. When --may-exist, logical_port, and external_mac  are
              all specified, the existing values of logical_port and external_mac are overwritten.

       [--if-exists] lr-nat-del router [type [ip]]
              Deletes  NATs  from  router.  If only router is supplied, all the NATs from the logical router are
              deleted. If type is also specified, then all the NATs that match the type 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  logical_ip.  When  type is dnat or
              dnat_and_snat, the ip shoud be external_ip.

              It is an error if ip is 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] 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 separator).
              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 separator). 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 or udp. 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.

              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 balancer 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 balancer 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
              chassis 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.

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 interchangeably. 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, inclusive.

              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. However, 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 characters. 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 single 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
       column’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-config=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 [column[:key]=value]...
                     Lists  the  data in each record in table whose column equals value or, if key is specified,
                     whose column contains a key with the specified value. The following operators may  be  used
                     where = is written in the syntax summary:

                     = != < > <= >=
                            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 elements. Identical sets are considered
                            equal. Otherwise, if the sets have different numbers of elements, then the set  with
                            more  elements  is  considered 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  identical
                            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.

                     For arithmetic operators (= != < > <= >=), when key is specified but a particular  record’s
                     column  does  not  contain  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 particular record’s column does not
                     contain  key,  the  comparison  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 output 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 usually 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 associated 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 column 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 columns: 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 significant 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 table. 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. Any of the  operators  !=,
                     <,  >,  <=, or >= may be substituted for = to test for inequality, less than, greater than,
                     less than or equal to, or greater than or equal to, respectively. (Don’t forget to escape <
                     or > from interpretation by the shell.)

                     If no column[:key]=value arguments are given, this command 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 beginning of a set of ovs-vsctl commands.
                            For  example,  wait-until  bridge  br0  --  get bridge br0 datapath_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 command and its arguments.

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  database to propagate down to the southbound database or all of the OVN
              chassis, according to the argument to --wait.

REMOTE CONNECTIVITY COMMANDS

       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 inactivity 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.

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 background and afterward uses the daemon to  execute  operations.  Over  several
       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 /var/run/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
       location 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 mode is experimental.

   Daemon Commands
       Daemon  mode  is  internally  implemented  using  the same mechanism used by ovs-appctl. One may also use
       ovs-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

       --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 committed 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 malfunctioning.)

            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.

            User can set one or more OVN_NBCTL_OPTIONS options in environment variable. Under the  Bourne  shell
            this might be done like this:

                      OVN_NBCTL_OPTIONS="--db=unix:nb1.ovsdb --no-leader-only"

            When  OVN_NBCTL_OPTIONS  is  set,  ovn-nbctl  automatically  and  transparently uses the environment
            variable to execute its commands. However user can still over-ride environment  options  by  passing
            different in cli.

            When the environment variable is no longer needed, unset it, e.g.:

                      unset OVN_NBCTL_OPTIONS

       --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  multiple  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 following 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 connect. This allows user  to  specify  the  preferred  order,
            which is particularly useful for testing.

   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 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.

       --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 (SIGABRT,  SIGALRM,  SIGBUS,  SIGFPE,  SIGILL,  SIGPIPE,  SIGSEGV,  SIGXCPU,  or
              SIGXFSZ) then the monitor process starts a new copy of it. If the daemon dies or exits for another
              reason, the monitor process exits.

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

       --no-chdir
              By  default,  when  --detach is specified, 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.

       --no-self-confinement
              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.

       --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 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.

       -v
       --verbose
            Sets the maximum logging verbosity level, equivalent to --verbose=dbg.

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

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

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

       --syslog-target=host:port
            Send  syslog  messages  to  UDP  port  on host, in addition to the system syslog. The host must be a
            numerical IP address, not a hostname.

       --syslog-method=method
            Specify method 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.

TABLE FORMATTING OPTIONS

       These options control the format of output from the list and find commands.

              -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 formatting 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 columns, items within sets and maps are space-separated,  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 possible. 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 certifies the private key specified on -p
                   or --private-key to be trustworthy.  The  certificate  must  be  signed  by  the  certificate
                   authority (CA) that the peer in SSL connections will use to verify it.

              -C cacert.pem
              --ca-cert=cacert.pem
                   Specifies  a  PEM  file containing the CA certificate 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
              --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 executable will attempt to obtain the CA certificate from the SSL  peer  on
                     its  first  SSL  connection and save it to the named PEM file. If it is successful, it will
                     immediately drop the connection and reconnect, and from then on all SSL connections must be
                     authenticated by a certificate signed by the CA certificate thus obtained.

                     This option exposes the SSL connection to a man-in-the-middle attack obtaining the  initial
                     CA certificate, but it may be useful for bootstrapping.

                     This  option  is  only  useful  if the SSL peer sends its CA certificate as part of the SSL
                     certificate chain. The SSL protocol does not require the server to send the CA certificate.

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

   Other Options
       -h
       --help
            Prints a brief help message to the console.

       -V
       --version
            Prints version information to the console.

Open vSwitch 20.03.2                                ovn-nbctl                                       ovn-nbctl(8)