Provided by: ovn-central_2.12.0-0ubuntu1_amd64 bug

NAME

       ovn-nb - OVN_Northbound database schema

       This  database is the interface between OVN and the cloud management system (CMS), such as
       OpenStack, running above it. The CMS produces almost all of the contents of the  database.
       The  ovn-northd  program monitors the database contents, transforms it, and stores it into
       the OVN_Southbound database.

       We generally speak of ``the’’ CMS, but one can imagine scenarios in which  multiple  CMSes
       manage different parts of an OVN deployment.

   External IDs
       Each  of  the  tables in this database contains a special column, named external_ids. This
       column has the same form and purpose each place it appears.

              external_ids: map of string-string pairs
                     Key-value pairs for use by the CMS. The CMS might  use  certain  pairs,  for
                     example,  to  identify  entities in its own configuration that correspond to
                     those in this database.

TABLE SUMMARY

       The following list summarizes the purpose of each of  the  tables  in  the  OVN_Northbound
       database.  Each table is described in more detail on a later page.

       Table     Purpose
       NB_Global Northbound configuration
       Logical_Switch
                 L2 logical switch
       Logical_Switch_Port
                 L2 logical switch port
       Address_Set
                 Address Sets
       Port_Group
                 Port Groups
       Load_Balancer
                 load balancer
       ACL       Access Control List (ACL) rule
       Logical_Router
                 L3 logical router
       QoS       QoS rule
       Meter     Meter entry
       Meter_Band
                 Band for meter entries
       Logical_Router_Port
                 L3 logical router port
       Logical_Router_Static_Route
                 Logical router static routes
       Logical_Router_Policy
                 Logical router policies
       NAT       NAT rules
       DHCP_Options
                 DHCP options
       Connection
                 OVSDB client connections.
       DNS       Native DNS resolution
       SSL       SSL configuration.
       Gateway_Chassis
                 Gateway_Chassis configuration.
       HA_Chassis_Group
                 HA_Chassis_Group configuration.
       HA_Chassis
                 HA_Chassis configuration.

NB_Global TABLE

       Northbound configuration for an OVN system. This table must have exactly one row.

   Summary:
       Status:
         nb_cfg                      integer
         sb_cfg                      integer
         hv_cfg                      integer
       Common Columns:
         external_ids                map of string-string pairs
       Common options:
         options                     map of string-string pairs
         Options for configuring BFD:
            options : bfd-min-rx     optional string
            options : bfd-decay-min-rx
                                     optional string
            options : bfd-min-tx     optional string
            options : bfd-mult       optional string
         options : mac_prefix        optional string
         options : controller_event  optional string, either true or false
       Connection Options:
         connections                 set of Connections
         ssl                         optional SSL
       Security Configurations:
         ipsec                       boolean

   Details:
     Status:

       These columns allow a client to track the overall configuration state of the system.

       nb_cfg: integer
              Sequence  number  for  client  to increment. When a client modifies any part of the
              northbound database configuration and wishes to wait for  ovn-northd  and  possibly
              all  of  the  hypervisors  to  finish  applying  the changes, it may increment this
              sequence number.

       sb_cfg: integer
              Sequence number that ovn-northd sets to the  value  of  nb_cfg  after  it  finishes
              applying the corresponding configuration changes to the OVN_Southbound database.

       hv_cfg: integer
              Sequence  number  that  ovn-northd  sets to the smallest sequence number of all the
              chassis in the system, as reported in the Chassis table in the southbound database.
              Thus,  hv_cfg  equals  nb_cfg  if  all  chassis  are  caught up with the northbound
              configuration (which may never happen, if any chassis  is  down).  This  value  can
              regress, if a chassis was removed from the system and rejoins before catching up.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

     Common options:

       options: map of string-string pairs
              This  column  provides  general  key/value  settings.  The  supported  options  are
              described individually below.

     Options for configuring BFD:

       These options apply when ovn-controller configures BFD on tunnels interfaces.

       options : bfd-min-rx: optional string
              BFD option min-rx value to use when configuring BFD on tunnel interfaces.

       options : bfd-decay-min-rx: optional string
              BFD option decay-min-rx value to use when configuring BFD on tunnel interfaces.

       options : bfd-min-tx: optional string
              BFD option min-tx value to use when configuring BFD on tunnel interfaces.

       options : bfd-mult: optional string
              BFD option mult value to use when configuring BFD on tunnel interfaces.

       options : mac_prefix: optional string
              Configure a given OUI to be used as prefix when L2 address is dynamically assigned,
              e.g. 00:11:22

       options : controller_event: optional string, either true or false
              Value set by the CMS to enable/disable ovn-controller event reporting. Traffic into
              OVS can raise a ’controller’ event that results in a Controller_Event being written
              to  the  Controller_Event  table in SBDB. When the CMS has seen the event and taken
              appropriate action, it can remove the correponding row in  Controller_Event  table.
              The  intention  is for a CMS to see the events and take some sort of action. Please
              see the Controller_Event table in SBDB.

     Connection Options:

       connections: set of Connections
              Database clients to which the Open vSwitch database server  should  connect  or  on
              which  it  should  listen,  along  with options for how these connections should be
              configured. See the Connection table for more information.

       ssl: optional SSL
              Global SSL configuration.

     Security Configurations:

       ipsec: boolean
              Tunnel encryption configuration. If this column is set to be true, all OVN  tunnels
              will be encrypted with IPsec.

Logical_Switch TABLE

       Each row represents one L2 logical switch.

       There  are  two kinds of logical switches, that is, ones that fully virtualize the network
       (overlay logical switches) and ones that provide simple connectivity to a physical network
       (bridged  logical switches). They work in the same way when providing connectivity between
       logical ports on same chasis,  but  differently  when  connecting  remote  logical  ports.
       Overlay  logical  switches  connect remote logical ports by tunnels, while bridged logical
       switches provide connectivity  to  remote  ports  by  bridging  the  packets  to  directly
       connected physical L2 segment with the help of localnet ports. Each bridged logical switch
       has one and only one localnet port, which has only one special address unknown.

   Summary:
       ports                         set of Logical_Switch_Ports
       load_balancer                 set of weak reference to Load_Balancers
       acls                          set of ACLs
       qos_rules                     set of QoSs
       dns_records                   set of weak reference to DNSs
       Naming:
         name                        string
         external_ids : neutron:network_name
                                     optional string
       IP Address Assignment:
         other_config : subnet       optional string
         other_config : exclude_ips  optional string
         other_config : ipv6_prefix  optional string
         other_config : mac_only     optional string, either true or false
       IP Multicast Snooping Options:
         other_config : mcast_snoop  optional string, either true or false
         other_config : mcast_querier
                                     optional string, either true or false
         other_config : mcast_flood_unregistered
                                     optional string, either true or false
         other_config : mcast_table_size
                                     optional string, containing an integer, in range 1 to 32,766
         other_config : mcast_idle_timeout
                                     optional string, containing an integer, in range 15 to 3,600
         other_config : mcast_query_interval
                                     optional string, containing an integer, in range 1 to 3,600
         other_config : mcast_query_max_response
                                     optional string, containing an integer, in range 1 to 10
         other_config : mcast_eth_src
                                     optional string
         other_config : mcast_ip4_src
                                     optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       ports: set of Logical_Switch_Ports
              The logical ports connected to the logical switch.

              It is an error for multiple logical switches to include the same logical port.

       load_balancer: set of weak reference to Load_Balancers
              Load balance a virtual ip address to a set of logical port endpoint ip addresses.

       acls: set of ACLs
              Access control rules that apply to packets within the logical switch.

       qos_rules: set of QoSs
              QoS marking and metering rules that apply to packets within the logical switch.

       dns_records: set of weak reference to DNSs
              This column defines the DNS records to be used for resolving internal  DNS  queries
              within the logical switch by the native DNS resolver. Please see the DNS table.

     Naming:

       These  columns  provide  names for the logical switch. From OVN’s perspective, these names
       have no special meaning or purpose other than to provide convenience for human interaction
       with  the  database.  There  is  no  requirement  for the name to be unique. (For a unique
       identifier for a logical switch, use its row UUID.)

       (Originally, name was intended to serve the purpose of  a  human-friendly  name,  but  the
       Neutron  integration  used  it  to  uniquely identify its own switch object, in the format
       neutron-uuid. Later on, Neutron started propagating the  friendly  name  of  a  switch  as
       external_ids:neutron:network_name. Perhaps this can be cleaned up someday.)

       name: string
              A name for the logical switch.

       external_ids : neutron:network_name: optional string
              Another name for the logical switch.

     IP Address Assignment:

       These  options  control  automatic  IP address management (IPAM) for ports attached to the
       logical  switch.  To  enable  IPAM  for  IPv4,  set  other_config:subnet  and   optionally
       other_config:exclude_ips.  To enable IPAM for IPv6, set other_config:ipv6_prefix. IPv4 and
       IPv6 may be enabled together or separately.

       To request dynamic address assignment for a particular port, use the  dynamic  keyword  in
       the addresses column of the port’s Logical_Switch_Port row. This requests both an IPv4 and
       an IPv6 address, if IPAM for IPv4 and IPv6 are both enabled.

       other_config : subnet: optional string
              Set  this  to  an  IPv4  subnet,  e.g.  192.168.0.0/24,  to  enable  ovn-northd  to
              automatically assign IP addresses within that subnet.

       other_config : exclude_ips: optional string
              To  exclude some addresses from automatic IP address management, set this to a list
              of the IPv4 addresses or ..-delimited ranges to exclude. The  addresses  or  ranges
              should be a subset of those in other_config:subnet.

              Whether  listed or not, ovn-northd will never allocate the first or last address in
              a subnet, such as 192.168.0.0 or 192.168.0.255 in 192.168.0.0/24.

              Examples:

              ·      192.168.0.2 192.168.0.10

              ·      192.168.0.4 192.168.0.30..192.168.0.60 192.168.0.110..192.168.0.120

              ·      192.168.0.110..192.168.0.120 192.168.0.25..192.168.0.30 192.168.0.144

       other_config : ipv6_prefix: optional string
              Set this to an IPv6 prefix  to  enable  ovn-northd  to  automatically  assign  IPv6
              addresses  using this prefix. The assigned IPv6 address will be generated using the
              IPv6 prefix and the MAC address (converted to an  IEEE  EUI64  identifier)  of  the
              port. The IPv6 prefix defined here should be a valid IPv6 address ending with ::.

              Examples:

              ·      aef0::

              ·      bef0:1234:a890:5678::

              ·      8230:5678::

       other_config : mac_only: optional string, either true or false
              Value  used  to request to assign L2 address only if neither subnet nor ipv6_prefix
              are specified

     IP Multicast Snooping Options:

       These options control IP Multicast Snooping configuration of the logical switch. To enable
       IP Multicast Snooping set other_config:mcast_snoop to true. To enable IP Multicast Querier
       set   other_config:mcast_snoop   to   true.   If   IP   Multicast   Querier   is   enabled
       other_config:mcast_eth_src and other_config:mcast_ip4_src must be set.

       other_config : mcast_snoop: optional string, either true or false
              Enables/disables IP Multicast Snooping on the logical switch.

       other_config : mcast_querier: optional string, either true or false
              Enables/disables IP Multicast Querier on the logical switch.

       other_config : mcast_flood_unregistered: optional string, either true or false
              Determines  whether  unregistered  multicast traffic should be flooded or not. Only
              applicable if other_config:mcast_snoop is enabled.

       other_config : mcast_table_size: optional string, containing an integer,  in  range  1  to
       32,766
              Number of multicast groups to be stored. Default: 2048.

       other_config  : mcast_idle_timeout: optional string, containing an integer, in range 15 to
       3,600
              Configures the IP Multicast Snooping group idle timeout (in seconds). Default:  300
              seconds.

       other_config : mcast_query_interval: optional string, containing an integer, in range 1 to
       3,600
              Configures the IP Multicast Querier interval between queries (in seconds). Default:
              other_config:mcast_idle_timeout / 2.

       other_config  : mcast_query_max_response: optional string, containing an integer, in range
       1 to 10
              Configures  the  value  of  the  "max-response"  field  in  the  multicast  queries
              originated by the logical switch. Default: 1 second.

       other_config : mcast_eth_src: optional string
              Configures  the  source  Ethernet  address  for  queries  originated by the logical
              switch.

       other_config : mcast_ip4_src: optional string
              Configures the source IPv4 address for queries originated by the logical switch.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Switch_Port TABLE

       A port within an L2 logical switch.

   Summary:
       Core Features:
         name                        string (must be unique within table)
         type                        string
       Options:
         options                     map of string-string pairs
         Options for router ports:
            options : router-port    optional string
            options : nat-addresses  optional string
         Options for localnet ports:
            options : network_name   optional string
         Options for l2gateway ports:
            options : network_name   optional string
            options : l2gateway-chassis
                                     optional string
         Options for vtep ports:
            options : vtep-physical-switch
                                     optional string
            options : vtep-logical-switch
                                     optional string
         VMI (or VIF) Options:
            options : requested-chassis
                                     optional string
            options : qos_max_rate   optional string
            options : qos_burst      optional string
         Virtual port Options:
            options : virtual-ip     optional string
            options : virtual-parents
                                     optional string
       Containers:
         parent_name                 optional string
         tag_request                 optional integer, in range 0 to 4,095
         tag                         optional integer, in range 1 to 4,095
       Port State:
         up                          optional boolean
         enabled                     optional boolean
       Addressing:
         addresses                   set of strings
         dynamic_addresses           optional string
         port_security               set of strings
       DHCP:
         dhcpv4_options              optional weak reference to DHCP_Options
         dhcpv6_options              optional weak reference to DHCP_Options
       ha_chassis_group              optional HA_Chassis_Group
       Naming:
         external_ids : neutron:port_name
                                     optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
     Core Features:

       name: string (must be unique within table)
              The logical port name.

              For entities (VMs or containers) that are spawned in the hypervisor, the name  used
              here  must  match  those  used  in  the  external_ids:iface-id  in the Open_vSwitch
              database’s Interface table, because  hypervisors  use  external_ids:iface-id  as  a
              lookup key to identify the network interface of that entity.

              For containers that share a VIF within a VM, the name can be any unique identifier.
              See Containers, below, for more information.

       type: string
              Specify a type for this logical port. Logical ports can  be  used  to  model  other
              types of connectivity into an OVN logical switch. The following types are defined:

              (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.

              external
                     Represents a logical port which is external and not having an  OVS  port  in
                     the integration bridge. OVN will never receive any traffic from this port or
                     send any traffic  to  this  port.  OVN  can  support  native  services  like
                     DHCPv4/DHCPv6/DNS   for   this   port.   If   ha_chassis_group  is  defined,
                     ovn-controller running in the master chassis of the HA  chassis  group  will
                     bind  this  port  to provide these native services. It is expected that this
                     port belong to a bridged logical switch (with a localnet port).

                     It is recommended to use the same HA chassis  group  for  all  the  external
                     ports of a logical switch. Otherwise, the physical switch might see MAC flap
                     issue when different chassis provide the native services. For  example  when
                     supporting   native   DHCPv4  service,  DHCPv4  server  mac  (configured  in
                     options:server_mac column in table DHCP_Options) originating from  different
                     ports can cause MAC flap issue. The MAC of the logical router IP(s) can also
                     flap if the same HA chassis group is not set for all the external ports of a
                     logical switch.

                     Below are some of the use cases where external ports can be used.

                     ·      VMs  connected  to SR-IOV nics - Traffic from these VMs by passes the
                            kernel stack and local ovn-controller do not  bind  these  ports  and
                            cannot serve the native services.

                     ·      When CMS supports provisioning baremetal servers.

              virtual
                     Represents a logical port which does not have an OVS port in the integration
                     bridge and has a virtual ip configured  in  the  options:virtual-ip  column.
                     This  virtual ip can move around between the logical ports configured in the
                     options:virtual-parents column.

                     One of the use case where virtual ports can be used is.

                     ·      The virtual ip represents a load balancer vip and the virtual parents
                            provide  load  balancer  service  in an active-standby setup with the
                            active virtual parent owning the virtual ip.

     Options:

       options: map of string-string pairs
              This column provides key/value settings specific to  the  logical  port  type.  The
              type-specific options are described individually below.

     Options for router ports:

       These options apply when type is router.

       options : router-port: optional string
              Required.  The name of the Logical_Router_Port to which this logical switch port is
              connected.

       options : nat-addresses: optional string
              This is used to send gratuitous ARPs  for  SNAT  and  DNAT  IP  addresses  via  the
              localnet port that is attached to the same logical switch as this type router port.
              This option is specified on a logical switch port that is connected  to  a  gateway
              router, or a logical switch port that is connected to a distributed gateway port on
              a logical router.

              This must take one of the following forms:

              router Gratuitous ARPs will be sent for all SNAT and DNAT external IP addresses and
                     for  all  load  balancer  IP  addresses defined on the options:router-port’s
                     logical router, using the options:router-port’s MAC address.

                     This form of options:nat-addresses is valid for logical switch  ports  where
                     options:router-port  is  the name of a port on a gateway router, or the name
                     of a distributed gateway port.

                     Supported only in OVN 2.8 and later. Earlier versions required NAT addresses
                     to be manually synchronized.

              Ethernet address followed by one or more IPv4 addresses
                     Example:  80:fa:5b:06:72:b7  158.36.44.22 158.36.44.24. This would result in
                     generation of gratuitous ARPs for IP addresses 158.36.44.22 and 158.36.44.24
                     with a MAC address of 80:fa:5b:06:72:b7.

                     This  form  of  options:nat-addresses is only valid for logical switch ports
                     where options:router-port is the name of a port on a gateway router.

     Options for localnet ports:

       These options apply when type is localnet.

       options : network_name: optional string
              Required. The name of the network to which the localnet  port  is  connected.  Each
              hypervisor,  via  ovn-controller, uses its local configuration to determine exactly
              how to connect to this locally accessible network.

     Options for l2gateway ports:

       These options apply when type is l2gateway.

       options : network_name: optional string
              Required. The name of the network to which the l2gateway port is connected. The  L2
              gateway,  via ovn-controller, uses its local configuration to determine exactly how
              to connect to this network.

       options : l2gateway-chassis: optional string
              Required. The chassis on which the l2gateway  logical  port  should  be  bound  to.
              ovn-controller running on the defined chassis will connect this logical port to the
              physical network.

     Options for vtep ports:

       These options apply when type is vtep.

       options : vtep-physical-switch: optional string
              Required. The name of the VTEP gateway.

       options : vtep-logical-switch: optional string
              Required. A logical switch name connected by the VTEP gateway.

     VMI (or VIF) Options:

       These options apply to logical ports with type having (empty string)

       options : requested-chassis: optional string
              If set, identifies a specific chassis (by name or hostname) that is allowed to bind
              this  port.  Using this option will prevent thrashing between two chassis trying to
              bind the same port during a live migration. It can also prevent  similar  thrashing
              due  to  a  mis-configuration,  if  a port is accidentally created on more than one
              chassis.

       options : qos_max_rate: optional string
              If set, indicates the maximum rate for data sent from this interface, in bit/s. The
              traffic will be shaped according to this limit.

       options : qos_burst: optional string
              If  set,  indicates  the  maximum  burst size for data sent from this interface, in
              bits.

     Virtual port Options:

       These options apply when type is virtual.

       options : virtual-ip: optional string
              This option represents the virtual IPv4 address.

       options : virtual-parents: optional string
              This options represents a set of logical port  names  (with  in  the  same  logical
              switch)  which  can  own  the  virtual ip configured in the options:virtual-ip. All
              these virtual parents should add the  virtual  ip  in  the  port_security  if  port
              security addressed are enabled.

     Containers:

       When  a  large  number  of  containers  are nested within a VM, it may be too expensive to
       dedicate a VIF to each container. OVN can use  VLAN  tags  to  support  such  cases.  Each
       container is assigned a VLAN ID and each packet that passes between the hypervisor and the
       VM is tagged with the appropriate ID for the container. Such VLAN IDs never  appear  on  a
       physical  wire,  even  inside  a  tunnel,  so they need not be unique except relative to a
       single VM on a hypervisor.

       These columns are used for VIFs that represent nested containers using  shared  VIFs.  For
       VMs and for containers that have dedicated VIFs, they are empty.

       parent_name: optional string
              The VM interface through which the nested container sends its network traffic. This
              must match the name column for some other Logical_Switch_Port.

       tag_request: optional integer, in range 0 to 4,095
              The VLAN  tag  in  the  network  traffic  associated  with  a  container’s  network
              interface.  The  client  can  request  ovn-northd  to allocate a tag that is unique
              within the scope of a specific parent (specified in parent_name) by setting a value
              of  0  in  this  column.  The  allocated  value is written by ovn-northd in the tag
              column. (Note that these tags are allocated and managed locally in  ovn-northd,  so
              they  cannot  be  reconstructed in the event that the database is lost.) The client
              can also request a specific non-zero tag and ovn-northd will honor it and copy that
              value to the tag column.

              When  type  is  set  to localnet or l2gateway, this can be set to indicate that the
              port represents a connection to a specific VLAN on a  locally  accessible  network.
              The  VLAN  ID  is  used  to  match  incoming  traffic and is also added to outgoing
              traffic.

       tag: optional integer, in range 1 to 4,095
              The VLAN tag allocated by ovn-northd based  on  the  contents  of  the  tag_request
              column.

     Port State:

       up: optional boolean
              This column is populated by ovn-northd, rather than by the CMS plugin as is most of
              this database. When a logical port is bound to  a  physical  location  in  the  OVN
              Southbound  database Binding table, ovn-northd sets this column to true; otherwise,
              or if the port becomes unbound later, it sets it to false. If this column is empty,
              the  port  is  not  considered  up.  This  allows  the  CMS  to wait for a VM’s (or
              container’s) networking to become active before it allows the VM (or container)  to
              start.

              Logical  ports of router type are an exception to this rule. They are considered to
              be always up, that is this column is always set to true.

       enabled: optional boolean
              This column is used to administratively set port state. If this column is empty  or
              is  set  to  true, the port is enabled. If this column is set to false, the port is
              disabled. A disabled port has all ingress and egress traffic dropped.

     Addressing:

       addresses: set of strings
              Addresses owned by the logical port.

              Each element in the set must take one of the following forms:

              Ethernet address followed by zero or more IPv4 or IPv6 addresses (or both)
                     An Ethernet address defined is owned by the logical port.  Like  a  physical
                     Ethernet NIC, a logical port ordinarily has a single fixed Ethernet address.

                     When  a  OVN  logical  switch  processes  a  unicast  Ethernet  frame  whose
                     destination MAC address is in a logical port’s addresses column, it delivers
                     it  only  to  that  port,  as if a MAC learning process had learned that MAC
                     address on the port.

                     If IPv4 or IPv6 address(es) (or both) are defined,  it  indicates  that  the
                     logical port owns the given IP addresses.

                     If   IPv4  address(es)  are  defined,  the  OVN  logical  switch  uses  this
                     information to synthesize responses to ARP requests without  traversing  the
                     physical network. The OVN logical router connected to the logical switch, if
                     any, uses this information to avoid issuing ARP requests for logical  switch
                     ports.

                     Note  that  the order here is important. The Ethernet address must be listed
                     before the IP address(es) if defined.

                     Examples:

                     80:fa:5b:06:72:b7
                            This indicates that the logical port owns the above mac address.

                     80:fa:5b:06:72:b7 10.0.0.4 20.0.0.4
                            This indicates that the logical port owns the  mac  address  and  two
                            IPv4 addresses.

                     80:fa:5b:06:72:b7 fdaa:15f2:72cf:0:f816:3eff:fe20:3f41
                            This  indicates that the logical port owns the mac address and 1 IPv6
                            address.

                     80:fa:5b:06:72:b7 10.0.0.4 fdaa:15f2:72cf:0:f816:3eff:fe20:3f41
                            This indicates that the logical port owns the mac address and 1  IPv4
                            address and 1 IPv6 address.

              unknown
                     This  indicates  that  the  logical  port  has  an  unknown  set of Ethernet
                     addresses. When an OVN logical switch processes  a  unicast  Ethernet  frame
                     whose destination MAC address is not in any logical port’s addresses column,
                     it delivers it to the  port  (or  ports)  whose  addresses  columns  include
                     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. ovn-northd will use the subnet
                     specified in other_config:subnet in the port’s Logical_Switch.

              Ethernet address followed by keyword "dynamic"
                     The keyword dynamic after the MAC address indicates that  ovn-northd  should
                     choose  an  unused  IPv4 address from the logical port’s subnet and store it
                     with the specified MAC in the port’s  dynamic_addresses  column.  ovn-northd
                     will   use  the  subnet  specified  in  other_config:subnet  in  the  port’s
                     Logical_Switch table.

                     Examples:

                     80:fa:5b:06:72:b7 dynamic
                            This indicates that the logical port owns the specified  MAC  address
                            and ovn-northd should allocate an unused IPv4 address for the logical
                            port from the corresponding logical switch subnet.

              Keyword "dynamic" followed by an IPv4/IPv6 address
                     The  keyword  dynamic  followed  by  an  IPv4/IPv6  address  indicates  that
                     ovn-northd  should  choose  a  dynamic ethernet address and use the provided
                     IPv4/IPv6 address as network address.

                     Examples:

                     dynamic 192.168.0.1 2001::1
                            This indicates that ovn-northd should allocate a unique  MAC  address
                            and use the provided IPv4/IPv6 address for the related port

              router Accepted  only  when type 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 options.

                     The   resulting   addresses  are  used  to  populate  the  logical  switch’s
                     destination lookup, and also for the logical switch to generate ARP  and  ND
                     replies.

                     If  the  connected  logical router port has a redirect-chassis specified and
                     the logical router has rules specified in nat with external_mac, then  those
                     addresses are also used to populate the switch’s destination lookup.

                     Supported  only  in  OVN  2.7  and  later.  Earlier versions required router
                     addresses to be manually synchronized.

       dynamic_addresses: optional string
              Addresses assigned to the logical port by ovn-northd, if dynamic  is  specified  in
              addresses.  Addresses  will  be  of  the  same  format  as  those that populate the
              addresses column. Note that dynamically  assigned  addresses  are  constructed  and
              managed  locally  in  ovn-northd, so they cannot be reconstructed in the event that
              the database is lost.

       port_security: set of strings
              This column controls the addresses from which the host attached to the logical port
              (``the  host’’)  is  allowed  to send packets and to which it is allowed to receive
              packets. If this column is empty, all addresses are permitted.

              Each element in the set must begin with one Ethernet address. This  would  restrict
              the  host  to  sending packets from and receiving packets to the ethernet addresses
              defined in the logical port’s port_security column. It  also  restricts  the  inner
              source  MAC  addresses  that  the  host may send in ARP and IPv6 Neighbor Discovery
              packets. The host is always allowed to receive packets to multicast  and  broadcast
              Ethernet addresses.

              Each element in the set may additionally contain one or more IPv4 or IPv6 addresses
              (or both), with optional masks. If a mask is given, it must  be  a  CIDR  mask.  In
              addition  to  the  restrictions  described  for  Ethernet  addresses above, such an
              element restricts the IPv4 or IPv6 addresses from which the host may  send  and  to
              which  it  may receive packets to the specified addresses. A masked address, if the
              host part is zero, indicates that the host is allowed to use  any  address  in  the
              subnet;  if  the  host  part  is nonzero, the mask simply indicates the size of the
              subnet. In addition:

              ·      If any IPv4 address is given, the host is also allowed to receive packets to
                     the  IPv4  local  broadcast  address  255.255.255.255  and to IPv4 multicast
                     addresses (224.0.0.0/4). If an IPv4 address with a mask is given,  the  host
                     is  also  allowed  to  receive  packets  to  the  broadcast  address in that
                     specified subnet.

                     If any IPv4 address is given, the host is additionally restricted to sending
                     ARP   packets   with  the  specified  source  IPv4  address.  (RARP  is  not
                     restricted.)

              ·      If any IPv6 address is given, the host is also allowed to receive packets to
                     IPv6 multicast addresses (ff00::/8).

                     If any IPv6 address is given, the host is additionally restricted to sending
                     IPv6 Neighbor Discovery  Solicitation  or  Advertisement  packets  with  the
                     specified source address or, for solicitations, the unspecified address.

              If an element includes an IPv4 address, but no IPv6 addresses, then IPv6 traffic is
              not allowed. If an element includes an IPv6 address, but no IPv4 address, then IPv4
              and ARP traffic is not allowed.

              This  column uses the same lexical syntax as the match column in the OVN Southbound
              database’s Pipeline table. Multiple addresses within an element  may  be  space  or
              comma separated.

              This  column  is  provided as a convenience to cloud management systems, but all of
              the features that it implements can be implemented as ACLs using the ACL table.

              Examples:

              80:fa:5b:06:72:b7
                     The host may send traffic from and receive  traffic  to  the  specified  MAC
                     address,  and  to  receive  traffic  to  Ethernet  multicast  and  broadcast
                     addresses, but not otherwise. The host may not send  ARP  or  IPv6  Neighbor
                     Discovery  packets  with  inner source Ethernet addresses other than the one
                     specified.

              80:fa:5b:06:72:b7 192.168.1.10/24
                     This adds further restrictions to the first example. The host may send  IPv4
                     packets  from  or  receive IPv4 packets to only 192.168.1.10, except that it
                     may also receive IPv4 packets to 192.168.1.255 (based on the  subnet  mask),
                     255.255.255.255,  and any address in 224.0.0.0/4. The host may not send ARPs
                     with a source Ethernet address other than 80:fa:5b:06:72:b7 or  source  IPv4
                     address  other  than 192.168.1.10. The host may not send or receive any IPv6
                     (including IPv6 Neighbor Discovery) traffic.

              "80:fa:5b:12:42:ba", "80:fa:5b:06:72:b7 192.168.1.10/24"
                     The host may send traffic from and receive  traffic  to  the  specified  MAC
                     addresses,  and  to  receive  traffic  to  Ethernet  multicast and broadcast
                     addresses, but not otherwise. With MAC 80:fa:5b:12:42:ba, the host may  send
                     traffic   from   and   receive   traffic   to   any  L3  address.  With  MAC
                     80:fa:5b:06:72:b7, the host may send  IPv4  packets  from  or  receive  IPv4
                     packets  to  only 192.168.1.10, except that it may also receive IPv4 packets
                     to 192.168.1.255 (based  on  the  subnet  mask),  255.255.255.255,  and  any
                     address in 224.0.0.0/4. The host may not send or receive any IPv6 (including
                     IPv6 Neighbor Discovery) traffic.

     DHCP:

       dhcpv4_options: optional weak reference to DHCP_Options
              This column defines the DHCPv4 Options to be included by the ovn-controller when it
              replies to the DHCPv4 requests. Please see the DHCP_Options table.

       dhcpv6_options: optional weak reference to DHCP_Options
              This column defines the DHCPv6 Options to be included by the ovn-controller when it
              replies to the DHCPv6 requests. Please see the DHCP_Options table.

       ha_chassis_group: optional HA_Chassis_Group
              References a row in  the  OVN  Northbound  database’s  HA_Chassis_Group  table.  It
              indicates  the  HA  chassis group to use if the type is set to external. If type is
              not external, this column is ignored.

     Naming:

       external_ids : neutron:port_name: optional string
              This column gives an optional human-friendly name for the port. This  name  has  no
              special  meaning or purpose other than to provide convenience for human interaction
              with the northbound database.

              Neutron copies this from its own port object’s name.  (Neutron  ports  do  are  not
              assigned human-friendly names by default, so it will often be empty.)

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

              The  ovn-northd  program copies all these pairs into the external_ids column of the
              Port_Binding table in OVN_Southbound database.

Address_Set TABLE

       Each row in this table represents a named set of addresses. An  address  set  may  contain
       Ethernet,  IPv4,  or  IPv6  addresses with optional bitwise or CIDR masks. Address set may
       ultimately be used in ACLs to compare against fields such as ip4.src or ip6.src. A  single
       address  set  must  contain addresses of the same type. As an example, the following would
       create an address set with three IP addresses:

             ovn-nbctl create Address_Set name=set1 addresses=’10.0.0.1 10.0.0.2 10.0.0.3’

       Address sets may be used in the match column of the ACL table. For syntax information, see
       the details of the expression language used for the match column in the Logical_Flow table
       of the OVN_Southbound database.

   Summary:
       name                          string (must be unique within table)
       addresses                     set of strings
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string (must be unique within table)
              A   name   for   the   address   set.   Names   are   ASCII    and    must    match
              [a-zA-Z_.][a-zA-Z_.0-9]*.

       addresses: set of strings
              The set of addresses in string form.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Port_Group TABLE

       Each row in this table represents a named group of logical switch ports.

       Port  groups may be used in the match column of the ACL table. For syntax information, see
       the details of the expression language used for the match column in the Logical_Flow table
       of the OVN_Southbound database.

       For  each port group, there are two address sets generated to the Address_Set table of the
       OVN_Southbound database, containing the IP addresses of the group of ports, one for  IPv4,
       and  the  other  for IPv6, with name being the name of the Port_Group followed by a suffix
       _ip4 for IPv4 and _ip6 for IPv6. The generated address sets can be used in the same way as
       regular address sets in the match column of the ACL table. For syntax information, see the
       details of the expression language used for the match column in the Logical_Flow table  of
       the OVN_Southbound database.

   Summary:
       name                          string (must be unique within table)
       ports                         set of weak reference to Logical_Switch_Ports
       acls                          set of ACLs
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string (must be unique within table)
              A name for the port group. Names are ASCII and must match [a-zA-Z_.][a-zA-Z_.0-9]*.

       ports: set of weak reference to Logical_Switch_Ports
              The logical switch ports belonging to the group in uuids.

       acls: set of ACLs
              Access  control rules that apply to the port group. Applying an ACL to a port group
              has the same effect as applying the ACL to all logical lswitches that the ports  of
              the port group belong to.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Load_Balancer TABLE

       Each row represents one load balancer.

   Summary:
       name                          string
       vips                          map of string-string pairs
       protocol                      optional string, either tcp or udp
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string
              A  name  for  the  load balancer. This name has no special meaning or purpose other
              than to provide convenience for human interaction with the ovn-nb database.

       vips: map of string-string pairs
              A map of virtual IP addresses (and an optional port number with : as  a  separator)
              associated  with  this  load balancer and their corresponding endpoint IP addresses
              (and optional port numbers with :  as  separators)  separated  by  commas.  If  the
              destination  IP  address  (and port number) of a packet leaving a container or a VM
              matches the virtual IP address (and port number) provided here as a key,  then  OVN
              will  statefully  replace  the  destination  IP  address  by one of the provided IP
              address (and port number) in this map as a  value.  IPv4  and  IPv6  addresses  are
              supported for load balancing; however a VIP of one address family may not be mapped
              to a destination IP address of a different family. If specifying  an  IPv6  address
              with  a port, the address portion must be enclosed in square brackets. Examples for
              keys are "192.168.1.4" and "[fd0f::1]:8800".  Examples  for  value  are  "10.0.0.1,
              10.0.0.2" and "20.0.0.10:8800, 20.0.0.11:8800".

              When  the  Load_Balancer  is  added  to  the logical_switch, the VIP has to be in a
              different subnet than the one used for  the  logical_switch.  Since  VIP  is  in  a
              different  subnet,  you  should connect your logical switch to either a OVN logical
              router or a real router (this is because the client can now send a packet with  VIP
              as  the  destination  IP  address  and  router’s mac address as the destination MAC
              address).

       protocol: optional string, either tcp or udp
              Valid protocols are tcp or udp. This  column  is  useful  when  a  port  number  is
              provided  as  part of the vips column. If this column is empty and a port number is
              provided as part of vips column, OVN assumes the protocol to be tcp.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

ACL TABLE

       Each row in this table represents one ACL rule for a logical switch or a port  group  that
       points  to it through its acls column. The action column for the highest-priority matching
       row in this table determines a packet’s treatment. If no row matches, packets are  allowed
       by  default.  (Default-deny treatment is possible: add a rule with priority 0, 1 as match,
       and deny as action.)

   Summary:
       priority                      integer, in range 0 to 32,767
       direction                     string, either from-lport or to-lport
       match                         string
       action                        string, one of allow-related, allow, drop, or reject
       Logging:
         log                         boolean
         name                        optional string, at most 63 characters long
         severity                    optional string, one  of  alert,  debug,  info,  notice,  or
                                     warning
         meter                       optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       priority: integer, in range 0 to 32,767
              The  ACL  rule’s  priority.  Rules with numerically higher priority take precedence
              over those with lower. If two ACL rules with the same priority both match, then the
              one actually applied to a packet is undefined.

              Return  traffic  from an allow-related flow is always allowed and cannot be changed
              through an ACL.

       direction: string, either from-lport or to-lport
              Direction of the traffic to which this rule should apply:

              ·      from-lport: Used to implement filters on traffic  arriving  from  a  logical
                     port. These rules are applied to the logical switch’s ingress pipeline.

              ·      to-lport:  Used to implement filters on traffic forwarded to a logical port.
                     These rules are applied to the logical switch’s egress pipeline.

       match: string
              The packets that the ACL should match, in the same expression language used for the
              match  column  in  the  OVN  Southbound  database’s Logical_Flow table. The outport
              logical port is only available in the to-lport direction (the inport  is  available
              in both directions).

              By  default  all  traffic is allowed. When writing a more restrictive policy, it is
              important to remember to allow flows  such  as  ARP  and  IPv6  neighbor  discovery
              packets.

              Note  that  you  can  not  create  an  ACL  matching  on a port with type=router or
              type=localnet.

       action: string, one of allow-related, allow, drop, or reject
              The action to take when the ACL rule matches:

              ·      allow: Forward the packet.

              ·      allow-related: Forward the packet and related traffic (e.g. inbound  replies
                     to an outbound connection).

              ·      drop: Silently drop the packet.

              ·      reject:  Drop  the  packet,  replying  with  a  RST for TCP or ICMPv4/ICMPv6
                     unreachable message for other IPv4/IPv6-based protocols.

     Logging:

       These columns control whether and how OVN logs packets that match an ACL.

       log: boolean
              If set to true, packets that match the ACL  will  trigger  a  log  message  on  the
              transport  node  or nodes that perform ACL processing. Logging may be combined with
              any action.

              If set to false, the remaining columns in this group have no significance.

       name: optional string, at most 63 characters long
              This name, if it  is  provided,  is  included  in  log  records.  It  provides  the
              administrator  and the cloud management system a way to associate a log record with
              a particular ACL.

       severity: optional string, one of alert, debug, info, notice, or warning
              The severity of the ACL. The severity levels match those of syslog,  in  decreasing
              level  of  severity:  alert,  warning,  notice,  info, or debug. When the column is
              empty, the default is info.

       meter: optional string
              The name of a meter to rate-limit log messages for the ACL. The string  must  match
              the name column of a row in the Meter table. By default, log messages are not rate-
              limited.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Router TABLE

       Each row represents one L3 logical router.

   Summary:
       ports                         set of Logical_Router_Ports
       static_routes                 set of Logical_Router_Static_Routes
       policies                      set of Logical_Router_Policys
       enabled                       optional boolean
       nat                           set of NATs
       load_balancer                 set of weak reference to Load_Balancers
       Naming:
         name                        string
         external_ids : neutron:router_name
                                     optional string
       Options:
         options : chassis           optional string
         options : dnat_force_snat_ip
                                     optional string
         options : lb_force_snat_ip  optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       ports: set of Logical_Router_Ports
              The router’s ports.

       static_routes: set of Logical_Router_Static_Routes
              Zero or more static routes for the router.

       policies: set of Logical_Router_Policys
              Zero or more routing policies for the router.

       enabled: optional boolean
              This column is used to administratively set router state. If this column  is  empty
              or  is  set  to  true,  the  router is enabled. If this column is set to false, the
              router is disabled. A disabled router has all ingress and egress traffic dropped.

       nat: set of NATs
              One or more NAT rules for the router. NAT rules only work on Gateway  routers,  and
              on  distributed  routers  with  one  logical  router  port  with a redirect-chassis
              specified.

       load_balancer: set of weak reference to Load_Balancers
              Load balance a virtual ip address to a set  of  logical  port  ip  addresses.  Load
              balancer rules only work on the Gateway routers.

     Naming:

       These  columns  provide  names for the logical router. From OVN’s perspective, these names
       have no special meaning or purpose other than to provide convenience for human interaction
       with  the  northbound  database. There is no requirement for the name to be unique. (For a
       unique identifier for a logical router, use its row UUID.)

       (Originally, name was intended to serve the purpose of  a  human-friendly  name,  but  the
       Neutron  integration  used  it  to  uniquely identify its own router object, in the format
       neutron-uuid. Later on, Neutron started propagating the  friendly  name  of  a  router  as
       external_ids:neutron:router_name. Perhaps this can be cleaned up someday.)

       name: string
              A name for the logical router.

       external_ids : neutron:router_name: optional string
              Another name for the logical router.

     Options:

       Additional options for the logical router.

       options : chassis: optional string
              If set, indicates that the logical router in question is a Gateway router (which is
              centralized) and resides in the set  chassis.  The  same  value  is  also  used  by
              ovn-controller  to  uniquely  identify  the chassis in the OVN deployment and comes
              from external_ids:system-id in the Open_vSwitch table of Open_vSwitch database.

              The Gateway router can only be connected to a distributed router via  a  switch  if
              SNAT and DNAT are to be configured in the Gateway router.

       options : dnat_force_snat_ip: optional string
              If  set,  indicates  the  IP address to use to force SNAT a packet that has already
              been DNATed in the gateway router. When multiple gateway routers are configured,  a
              packet  can potentially enter any of the gateway router, get DNATted and eventually
              reach the logical switch port. For the return  traffic  to  go  back  to  the  same
              gateway  router  (for  unDNATing), the packet needs a SNAT in the first place. This
              can be achieved by setting the above option with a gateway specific IP address.

       options : lb_force_snat_ip: optional string
              If set, indicates the IP address to use to force SNAT a  packet  that  has  already
              been  load-balanced  in  the  gateway  router.  When  multiple  gateway routers are
              configured, a packet can potentially enter any of the gateway routers, get  DNATted
              as  part  of  the load- balancing and eventually reach the logical switch port. For
              the return traffic to go back to the  same  gateway  router  (for  unDNATing),  the
              packet  needs  a SNAT in the first place. This can be achieved by setting the above
              option with a gateway specific IP address.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

QoS TABLE

       Each row in this table represents one QoS rule for a logical  switch  that  points  to  it
       through its qos_rules column. Two types of QoS are supported: DSCP marking and metering. A
       match with the highest-priority will have QoS applied to  it.  If  the  action  column  is
       specified,  then  matching packets will have DSCP marking applied. If the bandwdith column
       is specified, then matching packets will have metering applied. action and  bandwdith  are
       not  exclusive,  so both marking and metering by defined for the same QoS entry. If no row
       matches, packets will not have any QoS applied.

   Summary:
       priority                      integer, in range 0 to 32,767
       direction                     string, either from-lport or to-lport
       match                         string
       action                        map of string-integer pairs, key  must  be  dscp,  value  in
                                     range 0 to 63
       bandwidth                     map of string-integer pairs, key either burst or rate, value
                                     in range 1 to 4,294,967,295
       external_ids                  map of string-string pairs

   Details:
       priority: integer, in range 0 to 32,767
              The QoS rule’s priority. Rules with numerically  higher  priority  take  precedence
              over those with lower. If two QoS rules with the same priority both match, then the
              one actually applied to a packet is undefined.

       direction: string, either from-lport or to-lport
              The value of this field is similar to ACL column in the OVN  Northbound  database’s
              ACL table.

       match: string
              The  packets  that the QoS rules should match, in the same expression language used
              for the match column in the  OVN  Southbound  database’s  Logical_Flow  table.  The
              outport  logical  port  is  only available in the to-lport direction (the inport is
              available in both directions).

       action: map of string-integer pairs, key must be dscp, value in range 0 to 63
              When specified, matching flows will have DSCP marking applied.

              ·      dscp: The value  of  this  action  should  be  in  the  range  of  0  to  63
                     (inclusive).

       bandwidth:  map  of  string-integer  pairs,  key either burst or rate, value in range 1 to
       4,294,967,295
              When specified, matching packets will have bandwidth metering applied. Traffic over
              the limit will be dropped.

              ·      rate: The value of rate limit in kbps.

              ·      burst: The value of burst rate limit in kilobits. This is optional and needs
                     to specify the rate.

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Meter TABLE

       Each row in this table represents a meter that can be used for QoS or rate-limiting.

   Summary:
       name                          string (must be unique within table)
       unit                          string, either kbps or pktps
       bands                         set of 1 or more Meter_Bands
       external_ids                  map of string-string pairs

   Details:
       name: string (must be unique within table)
              A name for this meter.

              Names that begin with "__" (two underscores) are reserved for OVN internal use  and
              should not be added manually.

       unit: string, either kbps or pktps
              The  unit  for  rate  and  burst_rate parameters in the bands entry. kbps specifies
              kilobits per second, and pktps specifies packets per second.

       bands: set of 1 or more Meter_Bands
              The bands associated with this meter. Each band specifies a rate  above  which  the
              band  is to take the action action. If multiple bands’ rates are exceeded, then the
              band with the highest rate among the exceeded bands is selected.

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Meter_Band TABLE

       Each row in this table represents a meter band which specifies the rate  above  which  the
       configured action should be applied. These bands are referenced by the bands column in the
       Meter table.

   Summary:
       action                        string, must be drop
       rate                          integer, in range 1 to 4,294,967,295
       burst_size                    integer, in range 0 to 4,294,967,295
       external_ids                  map of string-string pairs

   Details:
       action: string, must be drop
              The action to execute when this band matches. The only supported action is drop.

       rate: integer, in range 1 to 4,294,967,295
              The rate limit for this band, in kilobits per second or bits per second,  depending
              on whether the parent Meter entry’s unit column specified kbps or pktps.

       burst_size: integer, in range 0 to 4,294,967,295
              The maximum burst allowed for the band in kilobits or packets, depending on whether
              kbps or pktps was selected in the parent Meter entry’s unit column. If the size  is
              zero,  the  switch  is  free  to  select  some  reasonable  value  depending on its
              configuration.

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Router_Port TABLE

       A port within an L3 logical router.

       Exactly one Logical_Router row must reference a given logical router port.

   Summary:
       name                          string (must be unique within table)
       gateway_chassis               set of Gateway_Chassiss
       ha_chassis_group              optional HA_Chassis_Group
       networks                      set of 1 or more strings
       mac                           string
       enabled                       optional boolean
       ipv6_ra_configs:
         ipv6_ra_configs : address_mode
                                     optional string
         ipv6_ra_configs : mtu       optional string
         ipv6_ra_configs : send_periodic
                                     optional string
         ipv6_ra_configs : max_interval
                                     optional string
         ipv6_ra_configs : min_interval
                                     optional string
       Options:
         options : redirect-chassis  optional string
         options : reside-on-redirect-chassis
                                     optional string
       Attachment:
         peer                        optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string (must be unique within table)
              A name for the logical router port.

              In addition to provide  convenience  for  human  interaction  with  the  northbound
              database, this column is used as reference by its patch port in Logical_Switch_Port
              or another logical router port in Logical_Router_Port.

       gateway_chassis: set of Gateway_Chassiss
              This column is ignored if the column ha_chassis_group. is set.

              If set, this indicates that this  logical  router  port  represents  a  distributed
              gateway  port  that  connects this router to a logical switch with a localnet port.
              There may be at most one such logical router port on each logical router.

              Several Gateway_Chassis can be referenced for a given logical router port. A single
              Gateway_Chassis  is  functionally  equivalent  to setting options:redirect-chassis.
              Refer to the description of  options:redirect-chassis  for  additional  details  on
              gateway handling.

              Defining  more than one Gateway_Chassis will enable gateway high availability. Only
              one gateway will be active  at  a  time.  OVN  chassis  will  use  BFD  to  monitor
              connectivity  to  a  gateway. If connectivity to the active gateway is interrupted,
              another gateway will become active. The priority column specifies  the  order  that
              gateways will be chosen by OVN.

       ha_chassis_group: optional HA_Chassis_Group
              If  set,  this  indicates  that  this  logical router port represents a distributed
              gateway port that connects this router to a logical switch with  a  localnet  port.
              There  may  be  at most one such logical router port on each logical router. The HA
              chassis which are part of the HA  chassis  group  will  provide  the  gateway  high
              availability. Please see the HA_Chassis_Group for more details.

              When this column is set, the column gateway_chassis will be ignored.

       networks: set of 1 or more strings
              The  IP addresses and netmasks of the router. For example, 192.168.0.1/24 indicates
              that  the  router’s  IP  address  is  192.168.0.1  and  that  packets  destined  to
              192.168.0.x should be routed to this port.

              A   logical   router  port  always  adds  a  link-local  IPv6  address  (fe80::/64)
              automatically generated from the interface’s MAC address using the modified  EUI-64
              format.

       mac: string
              The Ethernet address that belongs to this router port.

       enabled: optional boolean
              This  column is used to administratively set port state. If this column is empty or
              is set to true, the port is enabled. If this column is set to false,  the  port  is
              disabled. A disabled port has all ingress and egress traffic dropped.

     ipv6_ra_configs:

       This  column  defines  the  IPv6  ND  RA  address mode and ND MTU Option to be included by
       ovn-controller when it replies to the IPv6 Router solicitation requests.

       ipv6_ra_configs : address_mode: optional string
              The address mode to be used for IPv6 address configuration.  The  supported  values
              are:

              ·      slaac:  Address  configuration  using  Router Advertisement (RA) packet. The
                     IPv6 prefixes defined in the  Logical_Router_Port  table’s  networks  column
                     will be included in the RA’s ICMPv6 option - Prefix information.

              ·      dhcpv6_stateful: Address configuration using DHCPv6.

              ·      dhcpv6_stateless:  Address  configuration  using  Router  Advertisement (RA)
                     packet. Other IPv6 options are provided by DHCPv6.

       ipv6_ra_configs : mtu: optional string
              The recommended MTU for the link. Default is 0, which means no MTU Option  will  be
              included  in  RA  packet  replied by ovn-controller. Per RFC 2460, the mtu value is
              recommended no less than 1280, so any mtu value less than 1280 will  be  considered
              as no MTU Option.

       ipv6_ra_configs : send_periodic: optional string
              If  set  to  true,  then  this  router  interface  will  send router advertisements
              periodically. The default is false.

       ipv6_ra_configs : max_interval: optional string
              The  maximum  number  of  seconds  to  wait   between   sending   periodic   router
              advertisements.  This  option  has  no  effect  if ipv6_ra_configs:send_periodic is
              false. The default is 600.

       ipv6_ra_configs : min_interval: optional string
              The  minimum  number  of  seconds  to  wait   between   sending   periodic   router
              advertisements.  This  option  has  no  effect  if ipv6_ra_configs:send_periodic is
              false. The default is one-third of ipv6_ra_configs:max_interval, i.e.  200  seconds
              if that key is unset.

     Options:

       Additional options for the logical router port.

       options : redirect-chassis: optional string
              If  set,  this  indicates  that  this  logical router port represents a distributed
              gateway port that connects this router to a logical switch with  a  localnet  port.
              There may be at most one such logical router port on each logical router.

              Even   when  a  redirect-chassis  is  specified,  the  logical  router  port  still
              effectively resides on each chassis. However, due to the implications of the use of
              L2  learning  in  the  physical  network,  as  well as the need to support advanced
              features such as one-to-many NAT (aka IP masquerading), a  subset  of  the  logical
              router   processing   is   handled   in  a  centralized  manner  on  the  specified
              redirect-chassis.

              When this option is specified, the peer logical switch port’s addresses must be set
              to  router.  With  this  setting,  the  external_macs  specified  in  NAT rules are
              automatically programmed in the peer logical switch’s  destination  lookup  on  the
              chassis  where  the  logical_port  resides.  In  addition, the logical router’s MAC
              address is automatically programmed in the peer logical switch’s destination lookup
              flow on the redirect-chassis.

              When this option is specified and it is desired to generate gratuitous ARPs for NAT
              addresses, then the peer logical switch port’s options:nat-addresses should be  set
              to router.

              While  options:redirect-chassis  is still supported for backwards compatibility, it
              is now preferred to specify one or more gateway_chassis instead. It is functionally
              equivalent, but allows you to specify multiple chassis to enable high availability.

       options : reside-on-redirect-chassis: optional string
              Generally routing is distributed in OVN. The packet from a logical port which needs
              to be routed hits the router pipeline in the  source  chassis.  For  the  East-West
              traffic,  the  packet  is sent directly to the destination chassis. For the outside
              traffic the packet is sent to the gateway chassis.

              When this option is set, OVN considers this only if

              ·      The logical router to which this  logical  router  port  belongs  to  has  a
                     distributed gateway port.

              ·      The  peer’s  logical  switch has a localnet port (representing a VLAN tagged
                     network)

              When this option is set to true, then the packet which needs to be routed hits  the
              router  pipeline  in  the  chassis hosting the distributed gateway router port. The
              source chassis pushes out this traffic via the localnet port. With this  the  East-
              West traffic is no more distributed and will always go through the gateway chassis.

              Without  this  option  set, for any traffic destined to outside from a logical port
              which belongs to a logical switch with localnet port, the source chassis will  send
              the traffic to the gateway chassis via the tunnel port instead of the localnet port
              and this could cause MTU issues.

     Attachment:

       A given router port serves one of two purposes:

              ·      To attach a logical switch to a logical router. A  logical  router  port  of
                     this  type  is referenced by exactly one Logical_Switch_Port of type router.
                     The  value  of  name  is  set  as   router-port   in   column   options   of
                     Logical_Switch_Port. In this case peer column is empty.

              ·      To  connect  one  logical router to another. This requires a pair of logical
                     router ports, each connected to a different router. Each router port in  the
                     pair specifies the other in its peer column. No Logical_Switch refers to the
                     router port.

       peer: optional string
              For a router port used to connect two logical routers, this  identifies  the  other
              router port in the pair by name.

              For a router port attached to a logical switch, this column is empty.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Router_Static_Route TABLE

       Each record represents a static route.

       When  multiple  routes  match  a  packet,  the longest-prefix match is chosen. For a given
       prefix length, a dst-ip route is preferred over a src-ip route.

   Summary:
       ip_prefix                     string
       policy                        optional string, either dst-ip or src-ip
       nexthop                       string
       output_port                   optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       ip_prefix: string
              IP prefix of this route (e.g. 192.168.100.0/24).

       policy: optional string, either dst-ip or src-ip
              If it is specified,  this  setting  describes  the  policy  used  to  make  routing
              decisions. This setting must be one of the following strings:

              ·      src-ip: This policy sends the packet to the nexthop when the packet’s source
                     IP address matches ip_prefix.

              ·      dst-ip: This policy sends the  packet  to  the  nexthop  when  the  packet’s
                     destination IP address matches ip_prefix.

              If not specified, the default is dst-ip.

       nexthop: string
              Nexthop IP address for this route. Nexthop IP address should be the IP address of a
              connected router port or the IP address of a logical port.

       output_port: optional string
              The name of the Logical_Router_Port via which the packet needs to be sent out. This
              is optional and when not specified, OVN will automatically figure this out based on
              the nexthop. When this is specified and there are  multiple  IP  addresses  on  the
              router  port  and  none  of them are in the same subnet of nexthop, OVN chooses the
              first IP address as the one via which the nexthop is reachable.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Router_Policy TABLE

       Each row in this table represents one routing policy for a logical router that  points  to
       it through its policies column. The action column for the highest-priority matching row in
       this table determines a packet’s treatment. If no row  matches,  packets  are  allowed  by
       default.  (Default-deny treatment is possible: add a rule with priority 0, 1 as match, and
       drop as action.)

   Summary:
       priority                      integer, in range 0 to 32,767
       match                         string
       action                        string, one of allow, drop, or reroute
       nexthop                       optional string

   Details:
       priority: integer, in range 0 to 32,767
              The  routing  policy’s  priority.  Rules  with  numerically  higher  priority  take
              precedence over those with lower. A rule is uniquely identified by the priority and
              match string.

       match: string
              The packets that the routing policy should match, in the same  expression  language
              used for the match column in the OVN Southbound database’s Logical_Flow table.

              By  default  all  traffic is allowed. When writing a more restrictive policy, it is
              important to remember to allow flows  such  as  ARP  and  IPv6  neighbor  discovery
              packets.

       action: string, one of allow, drop, or reroute
              The action to take when the routing policy matches:

              ·      allow: Forward the packet.

              ·      drop: Silently drop the packet.

              ·      reroute: Reroute packet to nexthop.

       nexthop: optional string
              Next-hop  IP  address for this route, which should be the IP address of a connected
              router port or the IP address of a logical port.

NAT TABLE

       Each record represents a NAT rule.

   Summary:
       type                          string, one of dnat, dnat_and_snat, or snat
       external_ip                   string
       external_mac                  optional string
       logical_ip                    string
       logical_port                  optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       type: string, one of dnat, dnat_and_snat, or snat
              Type of the 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.

       external_ip: string
              An IPv4 address.

       external_mac: optional string
              A MAC address.

              This is only used on  the  gateway  port  on  distributed  routers.  This  must  be
              specified  in order for the NAT rule to be processed in a distributed manner on all
              chassis. If this is not specified for a NAT rule on a distributed router, then this
              NAT  rule will be processed in a centralized manner on the gateway port instance on
              the redirect-chassis.

              This MAC address must be unique on the logical switch  that  the  gateway  port  is
              attached  to.  If the MAC address used on the logical_port is globally unique, then
              that MAC address can be specified as this external_mac.

       logical_ip: string
              An IPv4 network (e.g 192.168.1.0/24) or an IPv4 address.

       logical_port: optional string
              The name of the logical port where the logical_ip resides.

              This is only used on distributed routers. This must be specified in order  for  the
              NAT  rule  to  be  processed in a distributed manner on all chassis. If this is not
              specified for a NAT rule on a distributed  router,  then  this  NAT  rule  will  be
              processed   in   a   centralized  manner  on  the  gateway  port  instance  on  the
              redirect-chassis.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

DHCP_Options TABLE

       OVN implements native DHCPv4 support which caters to the common use case of  providing  an
       IPv4 address to a booting instance by providing stateless replies to DHCPv4 requests based
       on statically configured address mappings. To do this it allows a  short  list  of  DHCPv4
       options to be configured and applied at each compute host running ovn-controller.

       OVN  also  implements  native  DHCPv6  support  which provides stateless replies to DHCPv6
       requests.

   Summary:
       cidr                          string
       DHCPv4 options:
         Mandatory DHCPv4 options:
            options : server_id      optional string
            options : server_mac     optional string
            options : lease_time     optional string,  containing  an  integer,  in  range  0  to
                                     4,294,967,295
         IPv4 DHCP Options:
            options : router         optional string
            options : netmask        optional string
            options : dns_server     optional string
            options : log_server     optional string
            options : lpr_server     optional string
            options : swap_server    optional string
            options : policy_filter  optional string
            options : router_solicitation
                                     optional string
            options : nis_server     optional string
            options : ntp_server     optional string
            options : tftp_server    optional string
            options : classless_static_route
                                     optional string
            options : ms_classless_static_route
                                     optional string
         Boolean DHCP Options:
            options : ip_forward_enable
                                     optional string, either 0 or 1
            options : router_discovery
                                     optional string, either 0 or 1
            options : ethernet_encap optional string, either 0 or 1
         Integer DHCP Options:
            options : default_ttl    optional string, containing an integer, in range 0 to 255
            options : tcp_ttl        optional string, containing an integer, in range 0 to 255
            options : mtu            optional  string,  containing  an  integer,  in  range 68 to
                                     65,535
            options : T1             optional string, containing  an  integer,  in  range  68  to
                                     4,294,967,295
            options : T2             optional  string,  containing  an  integer,  in  range 68 to
                                     4,294,967,295
         String DHCP Options:
            options : wpad           optional string
            options : bootfile_name  optional string
            options : path_prefix    optional string
            options : tftp_server_address
                                     optional string
            options : domain_name    optional string
       DHCPv6 options:
         Mandatory DHCPv6 options:
            options : server_id      optional string
         IPv6 DHCPv6 options:
            options : dns_server     optional string
         String DHCPv6 options:
            options : domain_search  optional string
            options : dhcpv6_stateless
                                     optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       cidr: string
              The DHCPv4/DHCPv6 options will be included if the logical port has its  IP  address
              in this cidr.

     DHCPv4 options:

       The  CMS  should define the set of DHCPv4 options as key/value pairs in the options column
       of this table. For ovn-controller to include these DHCPv4 options, the  dhcpv4_options  of
       Logical_Switch_Port should refer to an entry in this table.

     Mandatory DHCPv4 options:

       The following options must be defined.

       options : server_id: optional string
              The  IP  address  for  the  DHCP server to use. This should be in the subnet of the
              offered IP. This is also  included  in  the  DHCP  offer  as  option  54,  ``server
              identifier.’’

       options : server_mac: optional string
              The Ethernet address for the DHCP server to use.

       options : lease_time: optional string, containing an integer, in range 0 to 4,294,967,295
              The offered lease time in seconds,

              The DHCPv4 option code for this option is 51.

     IPv4 DHCP Options:

       Below are the supported DHCPv4 options whose values are an IPv4 address, e.g. 192.168.1.1.
       Some  options  accept  multiple  IPv4  addresses  enclosed  within  curly   braces,   e.g.
       {192.168.1.2,  192.168.1.3}.  Please  refer to RFC 2132 for more details on DHCPv4 options
       and their codes.

       options : router: optional string
              The IP address of a gateway for the client to use. This should be in the subnet  of
              the offered IP. The DHCPv4 option code for this option is 3.

       options : netmask: optional string
              The DHCPv4 option code for this option is 1.

       options : dns_server: optional string
              The DHCPv4 option code for this option is 6.

       options : log_server: optional string
              The DHCPv4 option code for this option is 7.

       options : lpr_server: optional string
              The DHCPv4 option code for this option is 9.

       options : swap_server: optional string
              The DHCPv4 option code for this option is 16.

       options : policy_filter: optional string
              The DHCPv4 option code for this option is 21.

       options : router_solicitation: optional string
              The DHCPv4 option code for this option is 32.

       options : nis_server: optional string
              The DHCPv4 option code for this option is 41.

       options : ntp_server: optional string
              The DHCPv4 option code for this option is 42.

       options : tftp_server: optional string
              The DHCPv4 option code for this option is 66.

       options : classless_static_route: optional string
              The DHCPv4 option code for this option is 121.

              This  option  can  contain  one  or more static routes, each of which consists of a
              destination descriptor and the IP address of the router  that  should  be  used  to
              reach that destination. Please see RFC 3442 for more details.

              Example: {30.0.0.0/24,10.0.0.10, 0.0.0.0/0,10.0.0.1}

       options : ms_classless_static_route: optional string
              The  DHCPv4  option  code  for  this  option  is  249.  This  option  is similar to
              classless_static_route supported by Microsoft Windows DHCPv4 clients.

     Boolean DHCP Options:

       These options accept a Boolean value, expressed as 0 for false or 1 for true.

       options : ip_forward_enable: optional string, either 0 or 1
              The DHCPv4 option code for this option is 19.

       options : router_discovery: optional string, either 0 or 1
              The DHCPv4 option code for this option is 31.

       options : ethernet_encap: optional string, either 0 or 1
              The DHCPv4 option code for this option is 36.

     Integer DHCP Options:

       These options accept a nonnegative integer value.

       options : default_ttl: optional string, containing an integer, in range 0 to 255
              The DHCPv4 option code for this option is 23.

       options : tcp_ttl: optional string, containing an integer, in range 0 to 255
              The DHCPv4 option code for this option is 37.

       options : mtu: optional string, containing an integer, in range 68 to 65,535
              The DHCPv4 option code for this option is 26.

       options : T1: optional string, containing an integer, in range 68 to 4,294,967,295
              This specifies the time interval from address assignment until  the  client  begins
              trying to renew its address. The DHCPv4 option code for this option is 58.

       options : T2: optional string, containing an integer, in range 68 to 4,294,967,295
              This  specifies  the  time interval from address assignment until the client begins
              trying to rebind its address. The DHCPv4 option code for this option is 59.

     String DHCP Options:

       These options accept a string value.

       options : wpad: optional string
              The DHCPv4 option code for this option is 252. This option is used as part  of  web
              proxy auto discovery to provide a URL for a web proxy.

       options : bootfile_name: optional string
              The  DHCPv4  option  code  for this option is 67. This option is used to identify a
              bootfile.

       options : path_prefix: optional string
              The DHCPv4 option code for this option is 210. In PXELINUX’  case  this  option  is
              used to set a common path prefix, instead of deriving it from the bootfile name.

       options : tftp_server_address: optional string
              The DHCPv4 option code for this option is 150. The option contains one or more IPv4
              addresses that the client MAY use. This  option  is  Cisco  proprietary,  the  IEEE
              standard that matches with this requirement is option 66 (tftp_server).

       options : domain_name: optional string
              The DHCPv4 option code for this option is 15. This option specifies the domain name
              that client should use when resolving hostnames via the Domain Name System.

     DHCPv6 options:

       OVN also implements native DHCPv6 support. The CMS should define the set of DHCPv6 options
       as  key/value  pairs. The define DHCPv6 options will be included in the DHCPv6 response to
       the DHCPv6 Solicit/Request/Confirm packet from the logical ports having the IPv6 addresses
       in the cidr.

     Mandatory DHCPv6 options:

       The following options must be defined.

       options : server_id: optional string
              The  Ethernet  address  for  the  DHCP  server to use. This is also included in the
              DHCPv6 reply as option 2, ``Server Identifier’’  to  carry  a  DUID  identifying  a
              server  between  a  client and a server. ovn-controller defines DUID based on Link-
              layer Address [DUID-LL].

     IPv6 DHCPv6 options:

       Below are the supported DHCPv6 options whose values are an  IPv6  address,  e.g.  aef0::4.
       Some  options  accept multiple IPv6 addresses enclosed within curly braces, e.g. {aef0::4,
       aef0::5}. Please refer to RFC 3315 for more details on DHCPv6 options and their codes.

       options : dns_server: optional string
              The DHCPv6 option code for this option is 23. This option specifies the DNS servers
              that the VM should use.

     String DHCPv6 options:

       These options accept string values.

       options : domain_search: optional string
              The  DHCPv6  option  code  for  this option is 24. This option specifies the domain
              search list the client should use to resolve hostnames with DNS.

              Example: "ovn.org".

       options : dhcpv6_stateless: optional string
              This option specifies the OVN native DHCPv6 will  work  in  stateless  mode,  which
              means  OVN  native  DHCPv6 will not offer IPv6 addresses for VM/VIF ports, but only
              reply other configurations, such as DNS and domain search list. When  setting  this
              option  with string value "true", VM/VIF will configure IPv6 addresses by stateless
              way. Default value for this option is false.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Connection TABLE

       Configuration for a database connection to an Open vSwitch database (OVSDB) client.

       This table primarily configures the Open vSwitch database server (ovsdb-server).

       The Open vSwitch database server can initiate and maintain active  connections  to  remote
       clients. It can also listen for database connections.

   Summary:
       Core Features:
         target                      string (must be unique within table)
       Client Failure Detection and Handling:
         max_backoff                 optional integer, at least 1,000
         inactivity_probe            optional integer
       Status:
         is_connected                boolean
         status : last_error         optional string
         status : state              optional  string,  one of ACTIVE, BACKOFF, CONNECTING, IDLE,
                                     or VOID
         status : sec_since_connect  optional string, containing an integer, at least 0
         status : sec_since_disconnect
                                     optional string, containing an integer, at least 0
         status : locks_held         optional string
         status : locks_waiting      optional string
         status : locks_lost         optional string
         status : n_connections      optional string, containing an integer, at least 2
         status : bound_port         optional string, containing an integer
       Common Columns:
         external_ids                map of string-string pairs
         other_config                map of string-string pairs

   Details:
     Core Features:

       target: string (must be unique within table)
              Connection methods for clients.

              The following connection methods are currently supported:

              ssl:host[:port]
                     The specified SSL port on the host at the given host, which can either be  a
                     DNS  name  (if  built  with  unbound  library) or an IP address. A valid SSL
                     configuration must be provided when this form is  used,  this  configuration
                     can be specified via command-line options or the SSL table.

                     If port is not specified, it defaults to 6640.

                     SSL  support is an optional feature that is not always built as part of Open
                     vSwitch.

              tcp:host[:port]
                     The specified TCP port on the host at the given host, which can either be  a
                     DNS  name  (if  built  with unbound library) or an IP address. If host is an
                     IPv6 address, wrap it in square brackets, e.g. tcp:[::1]:6640.

                     If port is not specified, it defaults to 6640.

              pssl:[port][:host]
                     Listens for SSL connections on the specified TCP port. Specify 0 for port to
                     have  the  kernel automatically choose an available port. If host, which can
                     either be a DNS name (if built with unbound library) or an  IP  address,  is
                     specified,  then  connections  are  restricted  to the resolved or specified
                     local IPaddress (either IPv4 or IPv6 address). If host is an  IPv6  address,
                     wrap in square brackets, e.g. pssl:6640:[::1]. If host is not specified then
                     it listens only on IPv4 (but not IPv6) addresses. A valid SSL  configuration
                     must  be  provided  when this form is used, this can be specified either via
                     command-line options or the SSL table.

                     If port is not specified, it defaults to 6640.

                     SSL support is an optional feature that is not always built as part of  Open
                     vSwitch.

              ptcp:[port][:host]
                     Listens  for  connections  on  the specified TCP port. Specify 0 for port to
                     have the kernel automatically choose an available port. If host,  which  can
                     either  be  a  DNS name (if built with unbound library) or an IP address, is
                     specified, then connections are restricted  to  the  resolved  or  specified
                     local  IP address (either IPv4 or IPv6 address). If host is an IPv6 address,
                     wrap it in square brackets, e.g. ptcp:6640:[::1]. If host is  not  specified
                     then it listens only on IPv4 addresses.

                     If port is not specified, it defaults to 6640.

              When  multiple  clients are configured, the target values must be unique. Duplicate
              target values yield unspecified results.

     Client Failure Detection and Handling:

       max_backoff: optional integer, at least 1,000
              Maximum number of milliseconds to wait  between  connection  attempts.  Default  is
              implementation-specific.

       inactivity_probe: optional integer
              Maximum  number  of  milliseconds  of  idle time on connection to the client before
              sending an inactivity probe message. If Open vSwitch does not communicate with  the
              client  for the specified number of seconds, it will send a probe. If a response is
              not received for the same additional amount  of  time,  Open  vSwitch  assumes  the
              connection  has  been  broken and attempts to reconnect. Default is implementation-
              specific. A value of 0 disables inactivity probes.

     Status:

       Key-value pair of is_connected is always updated. Other  key-value  pairs  in  the  status
       columns may be updated depends on the target type.

       When target specifies a connection method that listens for inbound connections (e.g. ptcp:
       or punix:), both n_connections and is_connected may also be updated  while  the  remaining
       key-value pairs are omitted.

       On  the  other hand, when target specifies an outbound connection, all key-value pairs may
       be updated, except  the  above-mentioned  two  key-value  pairs  associated  with  inbound
       connection targets. They are omitted.

       is_connected: boolean
              true if currently connected to this client, false otherwise.

       status : last_error: optional string
              A  human-readable  description  of the last error on the connection to the manager;
              i.e. strerror(errno). This key will exist only if an error has occurred.

       status : state: optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE, or VOID
              The state of the connection to the manager:

              VOID   Connection is disabled.

              BACKOFF
                     Attempting to reconnect at an increasing period.

              CONNECTING
                     Attempting to connect.

              ACTIVE Connected, remote host responsive.

              IDLE   Connection is idle. Waiting for response to keep-alive.

              These  values  may  change  in  the  future.  They  are  provided  only  for  human
              consumption.

       status : sec_since_connect: optional string, containing an integer, at least 0
              The  amount  of  time since this client last successfully connected to the database
              (in seconds). Value is empty if client has never successfully been connected.

       status : sec_since_disconnect: optional string, containing an integer, at least 0
              The amount of time since this  client  last  disconnected  from  the  database  (in
              seconds). Value is empty if client has never disconnected.

       status : locks_held: optional string
              Space-separated list of the names of OVSDB locks that the connection holds. Omitted
              if the connection does not hold any locks.

       status : locks_waiting: optional string
              Space-separated list of the names of OVSDB locks that the connection  is  currently
              waiting to acquire. Omitted if the connection is not waiting for any locks.

       status : locks_lost: optional string
              Space-separated list of the names of OVSDB locks that the connection has had stolen
              by another OVSDB client. Omitted if no locks have been stolen from this connection.

       status : n_connections: optional string, containing an integer, at least 2
              When target specifies a connection method  that  listens  for  inbound  connections
              (e.g. ptcp: or pssl:) and more than one connection is actually active, the value is
              the number of active connections. Otherwise, this key-value pair is omitted.

       status : bound_port: optional string, containing an integer
              When target is ptcp: or pssl:, this is the TCP port on which the  OVSDB  server  is
              listening. (This is particularly useful when target specifies a port of 0, allowing
              the kernel to choose any available port.)

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

       other_config: map of string-string pairs

DNS TABLE

       Each  row  in  this  table  stores the DNS records. The Logical_Switch table’s dns_records
       references these records.

   Summary:
       records                       map of string-string pairs
       external_ids                  map of string-string pairs

   Details:
       records: map of string-string pairs
              Key-value pair of DNS records with DNS query name as the key and value as a  string
              of IP address(es) separated by comma or space.

              Example:  "vm1.ovn.org" = "10.0.0.4 aef0::4"

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

SSL TABLE

       SSL configuration for ovn-nb database access.

   Summary:
       private_key                   string
       certificate                   string
       ca_cert                       string
       bootstrap_ca_cert             boolean
       ssl_protocols                 string
       ssl_ciphers                   string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       private_key: string
              Name of a PEM file containing the private key used as the switch’s identity for SSL
              connections to the controller.

       certificate: string
              Name of a PEM file containing a certificate, signed by  the  certificate  authority
              (CA)  used  by the controller and manager, that certifies the switch’s private key,
              identifying a trustworthy switch.

       ca_cert: string
              Name of a PEM file containing the CA certificate used to verify that the switch  is
              connected to a trustworthy controller.

       bootstrap_ca_cert: boolean
              If  set  to  true, then Open vSwitch will attempt to obtain the CA certificate from
              the controller 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.  It  may  still  be
              useful for bootstrapping.

       ssl_protocols: string
              List  of  SSL  protocols  to  be enabled for SSL connections. The default when this
              option is omitted is TLSv1,TLSv1.1,TLSv1.2.

       ssl_ciphers: string
              List of ciphers  (in  OpenSSL  cipher  string  format)  to  be  supported  for  SSL
              connections. The default when this option is omitted is HIGH:!aNULL:!MD5.

     Common Columns:

       The overall purpose of these columns is described under Common Columns at the beginning of
       this document.

       external_ids: map of string-string pairs

Gateway_Chassis TABLE

       Association of one or more chassis to a logical router port. The traffic going out through
       an  specific  router  port  will  be  redirected  to  a  chassis, or a set of them in high
       availability  configurations.  A  single  Gateway_Chassis   is   equivalent   to   setting
       options:redirect-chassis.  Using  Gateway_Chassis  allows associating multiple prioritized
       chassis with a single logical router port.

   Summary:
       name                          string (must be unique within table)
       chassis_name                  string
       priority                      integer, in range 0 to 32,767
       options                       map of string-string pairs
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string (must be unique within table)
              Name of the Gateway_Chassis.

              A suggested, but not required naming convention is ${port_name}_${chassis_name}.

       chassis_name: string
              Name of the chassis that we want to redirect traffic  through  for  the  associated
              logical  router  port. The value must match the name column of the Chassis table in
              the OVN_Southbound database.

       priority: integer, in range 0 to 32,767
              This is the priority of a chassis among all Gateway_Chassis belonging to  the  same
              logical router port.

       options: map of string-string pairs
              Reserved for future use.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

HA_Chassis_Group TABLE

       Table  representing  a group of chassis which can provide High availability services. Each
       chassis in the group is represented by the table HA_Chassis. The HA chassis  with  highest
       priority will be the master of this group. If the master chassis failover is detected, the
       HA chassis with the next higher priority takes over the responsibility  of  providing  the
       HA.  If  a distributed gateway router port references a row in this table, then the master
       HA chassis in this group provides the gateway functionality.

   Summary:
       name                          string (must be unique within table)
       ha_chassis                    set of HA_Chassiss
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string (must be unique within table)
              Name of the HA_Chassis_Group. Name should be unique.

       ha_chassis: set of HA_Chassiss
              A list of HA chassis which belongs to this group.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

HA_Chassis TABLE

   Summary:
       chassis_name                  string
       priority                      integer, in range 0 to 32,767
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       chassis_name: string
              Name of the chassis which is part of the HA chassis group. The value must match the
              name column of the Chassis table in the OVN_Southbound database.

       priority: integer, in range 0 to 32,767
              Priority of the chassis. Chassis with highest priority will be the master.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.