Provided by: ovn-common_23.09.0-1ubuntu1_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
       Copp      Control plane protection
       Logical_Switch
                 L2 logical switch
       Logical_Switch_Port
                 L2 logical switch port
       Forwarding_Group
                 forwarding group
       Address_Set
                 Address Sets
       Port_Group
                 Port Groups
       Load_Balancer
                 load balancer
       Load_Balancer_Group
                 load balancer group
       Load_Balancer_Health_Check
                 load balancer
       ACL       Access Control List (ACL) rule
       Logical_Router
                 L3 logical router
       QoS       QoS rule
       Mirror    Mirror Entry
       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.
       BFD       BFD configuration.
       Static_MAC_Binding
                 Static_MAC_Binding configuration.
       Chassis_Template_Var
                 Chassis_Template_Var configuration.

NB_Global TABLE

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

   Summary:
       Identity:
         name                        string
       Status:
         nb_cfg                      integer
         nb_cfg_timestamp            integer
         sb_cfg                      integer
         sb_cfg_timestamp            integer
         hv_cfg                      integer
         hv_cfg_timestamp            integer
       Common Columns:
         external_ids                map of string-string pairs
       Common options:
         options                     map of string-string pairs
         Options for configuring OVS 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 : mac_binding_removal_limit
                                     optional  string,  containing  an  integer,  in  range  0 to
                                     4,294,967,295
         options : fdb_removal_limit
                                     optional string,  containing  an  integer,  in  range  0  to
                                     4,294,967,295
         options : controller_event  optional string, either true or false
         options : northd_probe_interval
                                     optional string
         options : ic_probe_interval
                                     optional string
         options : nbctl_probe_interval
                                     optional string
         options : northd_trim_timeout
                                     optional string
         options : use_logical_dp_groups
                                     optional string
         options : use_parallel_build
                                     optional string
         options : ignore_lsp_down   optional string
         options : use_ct_inv_match  optional string
         options : default_acl_drop  optional string
         options : debug_drop_domain_id
                                     optional string
         options : debug_drop_collector_set
                                     optional string
         options : use_common_zone   optional string, either true or false
         options : northd-backoff-interval-ms
                                     optional string
         Options for configuring interconnection route advertisement:
            options : ic-route-adv   optional string
            options : ic-route-learn optional string
            options : ic-route-adv-default
                                     optional string
            options : ic-route-learn-default
                                     optional string
            options : ic-route-blacklist
                                     optional string
       Connection Options:
         connections                 set of Connections
         ssl                         optional SSL
       Security Configurations:
         ipsec                       boolean
       Read-only Options:
         options : max_tunid         optional string

   Details:
     Identity:

       name: string
              The  name  of the OVN cluster, which uniquely identifies the OVN cluster throughout
              all OVN clusters supposed to interconnect with each other.

     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.

       nb_cfg_timestamp: integer
              The  timestamp,  in  milliseconds  since the epoch, when ovn-northd sees the latest
              nb_cfg and starts processing.

              To print the timestamp as a human-readable date:

                        date -d "@$(ovn-nbctl get NB_Global . nb_cfg_timestamp | sed ’s/...$//’)"

       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.

       sb_cfg_timestamp: integer
              The  timestamp,  in milliseconds since the epoch, when ovn-northd finishes applying
              the  corresponding   configuration   changes   to   the   OVN_Southbound   database
              successfully.

       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_Private 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.

              If there are no chassis, then ovn-northd copies nb_cfg to  hv_cfg.  Thus,  in  this
              case,  the  (nonexistent)  hypervisors  are always considered to be caught up. This
              means that hypervisors can be "caught up" even in cases  where  sb_cfg  would  show
              that  the  southbound  database is not. To detect when both the hypervisors and the
              southbound database are caught up, a client should take the smaller of  sb_cfg  and
              hv_cfg.

       hv_cfg_timestamp: integer
              The  largest  timestamp,  in milliseconds since the epoch, of the smallest sequence
              number of all the chassis in the system, as reported in the  Chassis_Private  table
              in  the  southbound database. In other words, this timestamp reflects the time when
              the slowest chassis catches up with the northbound configuration, which  is  useful
              for end-to-end control plane latency measurement.

     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 OVS BFD:

       These options apply when ovn-controller configures OVS BFD on tunnels  interfaces.  Please
       note these parameters refer to legacy OVS BFD implementation and not to OVN BFD one.

       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 : mac_binding_removal_limit: optional string, containing an integer, in range 0 to
       4,294,967,295
              MAC  binding  aging  bulk  removal limit. This limits how many rows can expire in a
              single transaction. Default value is 0 which is unlimited. When we  hit  the  limit
              next batch removal is delayed by 5 s.

       options  :  fdb_removal_limit:  optional  string,  containing  an  integer,  in range 0 to
       4,294,967,295
              FDB aging bulk removal limit. This limits how many rows  can  expire  in  a  single
              transaction.  Default  value  is  0  which is unlimited. When we hit the limit next
              batch removal is delayed by 5 s.

       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 corresponding 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. It is possible to associate a meter to each
              controller event type in order to not overload the pinctrl thread under heavy load.
              Each event type relies on a meter with a defined name:

              •      empty_lb_backends: event-elb

       options : northd_probe_interval: optional string
              The  inactivity  probe  interval  of  the  connection  to  the  OVN  Northbound and
              Southbound databases from ovn-northd, in milliseconds. If the  value  is  zero,  it
              disables the connection keepalive feature.

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

       options : ic_probe_interval: optional string
              The  inactivity  probe  interval  of  the  connection  to  the  OVN  Northbound and
              Southbound databases from ovn-ic,  in  milliseconds.  If  the  value  is  zero,  it
              disables the connection keepalive feature.

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

       options : nbctl_probe_interval: optional string
              The inactivity probe interval of the connection to the OVN Northbound database from
              ovn-nbctl utility,  in  milliseconds.  If  the  value  is  zero,  it  disables  the
              connection keepalive feature.

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

              If  the  value  is  less  than zero, then the default inactivity probe interval for
              ovn-nbctl would be left intact (120000 ms).

       options : northd_trim_timeout: optional string
              When used, this configuration value specifies the time, in milliseconds, since  the
              last  ovn-northd  active  operation  after  which  memory trimming is performed. By
              default this is set to 30000 (30 seconds).

       options : use_logical_dp_groups: optional string
              Note: This option is deprecated, the only behavior is  to  always  combine  logical
              flows  by datapath groups. Changing the value or removing this option all toghether
              will have no effect.

              ovn-northd combines logical flows that differs only  by  logical  datapath  into  a
              single logical flow with logical datapath group attached.

       options : use_parallel_build: optional string
              If set to true, ovn-northd will attempt to compute logical flows in parallel.

              Parallel  computation  is  enabled  only  if the system has 4 or more cores/threads
              available to be used by ovn-northd.

              The default value is false.

       options : ignore_lsp_down: optional string
              If set to false, ARP/ND reply flows for logical switch ports will be installed only
              if  the  port  is  up,  i.e.  claimed by a Chassis. If set to true, these flows are
              installed regardless of the status of the port, which can  result  in  a  situation
              that  ARP  request  to  an  IP is resolved even before the relevant VM/container is
              running. For environments where this is not an issue, setting it to true can reduce
              the load and latency of the control plane. The default value is true.

       options : use_ct_inv_match: optional string
              If  set  to  false,  ovn-northd will not use the ct.inv field in any of the logical
              flow matches. The default value  is  true.  If  the  NIC  supports  offloading  OVS
              datapath  flows but doesn’t support offloading ct_state inv flag, then the datapath
              flows matching on this flag (either +inv or -inv) will not be offloaded. CMS should
              consider  setting  use_ct_inv_match  to false in such cases. This results in a side
              effect of the invalid packets getting  delivered  to  the  destination  VIF,  which
              otherwise would have been dropped by OVN.

       options : default_acl_drop: optional string
              If set to true., ovn-northd will generate a logical flow to drop all traffic in the
              ACL stages. By default this option is set to false.

       options : debug_drop_domain_id: optional string
              If set to a 8-bit  number  and  if  debug_drop_collector_set  is  also  configured,
              ovn-northd  will  add  a sample action to every logical flow that contains a ’drop’
              action. The 8 most significant bits of  the  observation_domain_id  field  will  be
              those  specified in the  debug_drop_domain_id. The 24 least significant bits of the
              observation_domain_id field will be the datapath’s key.

              The observation_point_id will be set to the first 32 bits  of  the  logical  flow’s
              UUID.

       options : debug_drop_collector_set: optional string
              If set to a 32-bit number ovn-northd will add a sample action to every logical flow
              that  contains  a  ’drop’  action.  The  sample  action  will  have  the  specified
              collector_set_id.  The  value  must  match  that  of the local OVS configuration as
              described in ovs-actions(7).

       options : use_common_zone: optional string, either true or false
              Default value is false. If set to true the SNAT and DNAT happens  in  common  zone,
              instead  of  happening  in separate zones, depending on the configuration. However,
              this option breaks traffic when there is configuration of DGP + LB + SNAT  on  this
              LR. The value true should be used only in case of HWOL compatibility with GDP.

       options : northd-backoff-interval-ms: optional string
              Maximum  interval that the northd incremental engine is delayed by in milliseconds.
              Setting the value to nonzero delays the next northd engine run by the previous  run
              time,  capped  by  the  specified  value.  If the value is zero the engine won’t be
              delayed at all. The recommended period is smaller than  500  ms,  beyond  that  the
              latency of SB changes would be very noticeable.

     Options for configuring interconnection route advertisement:

       These   options   control   how   routes   are  advertised  between  OVN  deployments  for
       interconnection. If enabled,  ovn-ic  from  different  OVN  deployments  exchanges  routes
       between  each other through the global OVN_IC_Southbound database. Only routers with ports
       connected to interconnection transit switches participate in route advertisement. For each
       of these routers, there are two types of routes to be advertised:

       Firstly, the static routes configured in the router are advertised.

       Secondly,  the networks configured in the logical router ports that are not on the transit
       switches are advertised. These are considered as directly connected subnets on the router.

       Link local prefixes (IPv4 169.254.0.0/16 and IPv6 FE80::/10) are never advertised.

       The learned routes are added to the static_routes column of the Logical_Router table, with
       external_ids:ic-learned-route  set  to  the  uuid  of  the  row  in  Route  table  of  the
       OVN_IC_Southbound database.

       options : ic-route-adv: optional string
              A boolean value that enables route advertisement to  the  global  OVN_IC_Southbound
              database. Default is false.

       options : ic-route-learn: optional string
              A  boolean  value  that  enables  route  learning from the global OVN_IC_Southbound
              database. Default is false.

       options : ic-route-adv-default: optional string
              A  boolean  value  that  enables  advertising   default   route   to   the   global
              OVN_IC_Southbound  database.  Default  is false. This option takes effect only when
              option ic-route-adv is true.

       options : ic-route-learn-default: optional string
              A  boolean  value  that  enables   learning   default   route   from   the   global
              OVN_IC_Southbound  database.  Default  is false. This option takes effect only when
              option ic-route-learn is true.

       options : ic-route-blacklist: optional string
              A string value contains a list of CIDRs delimited by  ",".  A  route  will  not  be
              advertised or learned if the route’s prefix belongs to any of the CIDRs listed.

     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.

     Read-only Options:

       options : max_tunid: optional string
              The maximum supported tunnel ID. Depends on types of encapsulation enabled  in  the
              cluster.

Copp TABLE

       This  table  is  used to define control plane protection policies, i.e., associate entries
       from table Meter to control protocol names.

   Summary:
       name                          string (must be unique within table)
       meters : arp                  optional string
       meters : arp-resolve          optional string
       meters : dhcpv4-opts          optional string
       meters : dhcpv6-opts          optional string
       meters : dns                  optional string
       meters : event-elb            optional string
       meters : icmp4-error          optional string
       meters : icmp6-error          optional string
       meters : igmp                 optional string
       meters : nd-na                optional string
       meters : nd-ns                optional string
       meters : nd-ns-resolve        optional string
       meters : nd-ra-opts           optional string
       meters : tcp-reset            optional string
       meters : bfd                  optional string
       meters : reject               optional string
       meters : svc-monitor          optional string
       external_ids                  map of string-string pairs

   Details:
       name: string (must be unique within table)
              CoPP name.

       meters : arp: optional string
              Rate limiting meter for ARP packets (request/reply) used for learning neighbors.

       meters : arp-resolve: optional string
              Rate limiting meter for packets that require resolving the next-hop (through ARP).

       meters : dhcpv4-opts: optional string
              Rate limiting meter for packets that require adding DHCPv4 options.

       meters : dhcpv6-opts: optional string
              Rate limiting meter for packets that require adding DHCPv6 options.

       meters : dns: optional string
              Rate limiting meter for DNS query packets that need to be replied to.

       meters : event-elb: optional string
              Rate limiting meter for empty load balancer events.

       meters : icmp4-error: optional string
              Rate limiting meter for packets that require replying with an ICMP error.

       meters : icmp6-error: optional string
              Rate limiting meter for packets that require replying with an ICMPv6 error.

       meters : igmp: optional string
              Rate limiting meter for IGMP packets.

       meters : nd-na: optional string
              Rate limiting meter  for  ND  neighbor  advertisement  packets  used  for  learning
              neighbors.

       meters : nd-ns: optional string
              Rate  limiting  meter  for  ND  neighbor  solicitation  packets  used  for learning
              neighbors.

       meters : nd-ns-resolve: optional string
              Rate limiting meter for packets that require resolving the next-hop (through ND).

       meters : nd-ra-opts: optional string
              Rate limiting meter  for  packets  that  require  adding  ND  router  advertisement
              options.

       meters : tcp-reset: optional string
              Rate limiting meter for packets that require replying with TCP RST packet.

       meters : bfd: optional string
              Rate limiting meter for BFD packets.

       meters : reject: optional string
              Rate limiting meter for packets that trigger a reject action

       meters : svc-monitor: optional string
              Rate limiting meter for packets that are arriving to service monitor MAC address.

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

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 physical  networks
       (bridged  logical switches). They work in the same way when providing connectivity between
       logical ports on same chassis, 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  segments  with  the  help of localnet ports. Each bridged logical
       switch has one or more localnet ports, which have only one special address unknown.

   Summary:
       ports                         set of Logical_Switch_Ports
       load_balancer                 set of weak reference to Load_Balancers
       load_balancer_group           set of Load_Balancer_Groups
       acls                          set of ACLs
       qos_rules                     set of QoSes
       dns_records                   set of weak reference to DNSes
       forwarding_groups             set of Forwarding_Groups
       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
         other_config : fdb_age_threshold
                                     optional string,  containing  an  integer,  in  range  0  to
                                     4,294,967,295
       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
         other_config : mcast_ip6_src
                                     optional string
       Interconnection:
         other_config : interconn-ts
                                     optional string
       Tunnel Key:
         other_config : requested-tnl-key
                                     optional  string,  containing  an  integer,  in  range  1 to
                                     16,777,215
       copp                          optional weak reference to Copp
       Other options:
         other_config : vlan-passthru
                                     optional string, either true or false
         other_config : broadcast-arps-to-all-routers
                                     optional string, either true or false
       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
              Set of load balancers associated to this logical switch.

       load_balancer_group: set of Load_Balancer_Groups
              Set of load balancers groups associated to this logical switch.

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

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

       dns_records: set of weak reference to DNSes
              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.

       forwarding_groups: set of Forwarding_Groups
              Groups a set of logical port endpoints for traffic going out of the logical switch.

     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:

              •      192.168.0.2 192.168.0.10192.168.0.4 192.168.0.30..192.168.0.60 192.168.0.110..192.168.0.120192.168.0.110..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

       other_config : fdb_age_threshold: optional string, containing an integer, in  range  0  to
       4,294,967,295
              FDB  aging  threshold  value  in  seconds.  FDB  exceeding  this  timeout  will  be
              automatically removed. The value defaults to 0, which means disabled.

     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_querier  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. Default: false.

       other_config : mcast_querier: optional string, either true or false
              Enables/disables  IP  Multicast  Querier  on the logical switch. Only applicable if
              other_config:mcast_snoop is enabled. Default: true.

       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. Default: false.

       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.

       other_config : mcast_ip6_src: optional string
              Configures the source IPv6 address for queries originated by the logical switch.

     Interconnection:

       other_config : interconn-ts: optional string
              The  name  of corresponding transit switch in OVN_IC_Northbound database. This kind
              of logical switch is created and controlled by ovn-ic.

     Tunnel Key:

       other_config : requested-tnl-key: optional string, containing an integer, in  range  1  to
       16,777,215
              Configures  the  datapath  tunnel  key  for the logical switch. Usually this is not
              needed because ovn-northd will assign an unique key for each  datapath  by  itself.
              However,  if  it is configured, ovn-northd honors the configured value. The typical
              use case is for interconnection: the tunnel keys for transit switches  need  to  be
              unique  globally,  so they are maintained in the global OVN_IC_Southbound database,
              and ovn-ic simply syncs the value from OVN_IC_Southbound through this config.

       copp: optional weak reference to Copp
              The control plane protection policy from table Copp used for metering packets  sent
              to ovn-controller from ports of this logical switch.

     Other options:

       other_config : vlan-passthru: optional string, either true or false
              Determines  whether  VLAN tagged incoming traffic should be allowed. Note that this
              may have security implications when enabled for  a  logical  switch  with  a  tag=0
              localnet  port.  If not properly isolated from other localnet ports, fabric traffic
              that belongs to other tagged networks may be passed through such a port.

       other_config : broadcast-arps-to-all-routers: optional string, either true or false
              Determines whether arp requests and ipv6 neighbor solicitations should be  sent  to
              all  routers  and  other  switchports  (default)  or  if  it should only be sent to
              switchports where the  ip/mac  address  is  unknown.  Setting  this  to  false  can
              significantly  reduce  the  load if the logical switch can receive arp requests for
              ips it does not know about. However setting this to false also means that garps are
              no longer forwarded to all routers and therefor the mac bindings of the routers are
              no longer updated.

     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 : exclude-lb-vips-from-garp
                                     optional string
            options : arp_proxy      optional string
         Options for localnet ports:
            options : network_name   optional string
            options : ethtype        optional string
            options : localnet_learn_fdb
                                     optional string, either true or false
         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 : activation-strategy
                                     optional string
            options : iface-id-ver   optional string
            options : qos_min_rate   optional string
            options : qos_max_rate   optional string
            options : qos_burst      optional string
            options : hostname       optional string
            VIF Plugging Options:
              options : vif-plug-type
                                     optional string
              options : vif-plug-mtu-request
                                     optional string
         Virtual port Options:
            options : virtual-ip     optional string
            options : virtual-parents
                                     optional string
         IP Multicast Snooping Options:
            options : mcast_flood    optional string, either true or false
            options : mcast_flood_reports
                                     optional string, either true or false
       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
       mirror_rules                  set of weak reference to Mirrors
       ha_chassis_group              optional HA_Chassis_Group
       Naming:
         external_ids : neutron:port_name
                                     optional string
       Tunnel Key:
         options : requested-tnl-key
                                     optional string, containing an integer, in range 1 to 32,767
       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.

              A logical switch port may not have the same name as a logical router port, but  the
              database schema cannot enforce this.

       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. The value of options:router-port specifies
                     the  name  of  the  Logical_Router_Port to which this logical switch port is
                     connected.

              localnet
                     A connection to a locally accessible network from  ovn-controller  instances
                     that have a corresponding bridge mapping. A logical switch can have multiple
                     localnet ports attached. This type is used to model direct  connectivity  to
                     existing  networks. In this case, each chassis should have a mapping for one
                     of the physical networks only. Note:  nothing  said  above  implies  that  a
                     chassis  cannot  be  plugged  to  multiple physical networks as long as they
                     belong to different switches.

              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.

              remote A remote port is to model a port that resides remotely on another OVN, which
                     is on the other side of a transit logical switch  for  OVN  interconnection.
                     This  type  of  ports are created by ovn-ic instead of by CMS. Any change to
                     the port will be automatically overwritten by ovn-ic.

     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 : exclude-lb-vips-from-garp: optional string
              If options:nat-addresses is set to router, Gratuitous ARPs will  be  sent  for  all
              SNAT  and  DNAT  external IP addresses defined on the options:router-port’s logical
              router, using the options:router-port’s MAC address, not cosidering configured load
              balancers.

       options : arp_proxy: optional string
              Optional.  A  list  of  MAC  and  addresses/cidrs or just addresses/cidrs that this
              logical  switch  router  port   will   reply   to   ARP/NDP   requests.   Examples:
              169.254.239.254   169.254.239.2,  0a:58:a9:fe:01:01  169.254.239.254  169.254.239.2
              169.254.238.0/24, fd7b:6b4d:7b25:d22f::1 fd7b:6b4d:7b25:d22f::2,  0a:58:a9:fe:01:01
              fd7b:6b4d:7b25:d22f::0/64.  Theoptions:router-port’s  logical  router should have a
              route to forward packets sent to configured proxy ARP  MAC/IPs  to  an  appropriate
              destination.

     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, if at all.

       options : ethtype: optional string
              Optional.  VLAN  EtherType  field  value  for encapsulating VLAN headers. Supported
              values: 802.11q (default), 802.11ad.

       options : localnet_learn_fdb: optional string, either true or false
              Optional. Allows localnet port to learn MACs and store them in FDB table if set  to
              true. The default value is false.

     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.

              If  set  to a comma separated list, the first entry identifies the main chassis and
              the rest are one or more additional chassis that are allowed to bind the same port.

              When multiple chassis are set for the port, and the logical switch is connected  to
              an  external network through a localnet port, tunneling is enforced for the port to
              guarantee delivery of packets directed to the port to all its locations.  This  has
              MTU  implications  because the network used for tunneling must have MTU larger than
              localnet for stable connectivity.

              If the same host co-hosts more than one controller instance  (either  belonging  to
              the  same  or separate clusters), special attention should be given to consistently
              using unique chassis names used in this option. It is advised that chassis names  -
              and not host names - are used for this option.

       options : activation-strategy: optional string
              If  used  with  multiple  chassis set in requested-chassis, specifies an activation
              strategy for all additional chassis. By default, no activation  strategy  is  used,
              meaning  additional  port  locations are immediately available for use. When set to
              "rarp", the port is blocked for ingress  and  egress  communication  until  a  RARP
              packet is sent from a new location. The "rarp" strategy is useful in live migration
              scenarios for virtual machines.

       options : iface-id-ver: optional string
              If set, this port will be bound by ovn-controller only if this same key  and  value
              is  configured  in the external_ids column in the Open_vSwitch database’s Interface
              table.

       options : qos_min_rate: optional string
              If set, indicates the minimum guaranteed rate available for  data  sent  from  this
              interface, in bit/s.

       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.

       options : hostname: optional string
              If set, indicates the DHCPv4 option "Hostname" (option code 12) associated for this
              Logical Switch Port. If DHCPv4 is enabled for this Logical  Switch  Port,  hostname
              dhcp option will be included in DHCP reply.

     VIF Plugging Options:

       options : vif-plug-type: optional string
              If set, OVN will attempt to perform plugging of this VIF. In order to get this port
              plugged by the OVN controller, OVN must be built with support for VIF plugging. The
              default behavior is for the CMS to do the VIF plugging. Each VIF plug provider have
              their own options  namespaced  by  name,  for  example  "vif-plug:representor:key".
              Please    refer    to    the   VIF   plug   provider   documentation   located   in
              Documentation/topics/vif-plug-providers/ for more information.

       options : vif-plug-mtu-request: optional string
              Requested MTU for plugged interfaces. When set the OVN  controller  will  fill  the
              mtu_request  column  of  the  Open vSwitch database’s Interface table. This in turn
              will make OVS vswitchd update the MTU of the linked interface.

     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.

     IP Multicast Snooping Options:

       These  options  apply  when  the  port  is part of a logical switch which has other_config
       :mcast_snoop set to true.

       options : mcast_flood: optional string, either true or false
              If set to true, multicast packets (except reports) are unconditionally forwarded to
              the specific port. Default: false.

       options : mcast_flood_reports: optional string, either true or false
              If  set  to  true,  multicast reports are unconditionally forwarded to the specific
              port. Default: false.

     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.  Note:  for
              performance of the OVN  Southbound  database  conditional  monitoring,  unlike  for
              regular  VIFs, ovn-controller will register to get updates about all OVN Southbound
              database Port_Binding table records that correspond to nested container ports  even
              if  external_ids:ovn-monitor-all  is  set  to false. See ovn-controller(8) for more
              information.

       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  dynamic  to  make  ovn-northd  generate  a globally unique MAC address,
                     choose  an  unused  IPv4  address  with  the  logical  port’s   subnet   (if
                     other_config:subnet  is  set  in the port’s Logical_Switch), and generate an
                     IPv6 address from the MAC address (if other_config:ipv6_prefix is set in the
                     port’s  Logical_Switch)  and  store  them  in  the  port’s dynamic_addresses
                     column.

                     Only one element containing dynamic may appear in addresses.

              dynamic ip
              dynamic ipv6
              dynamic ip ipv6
                   These act like dynamic alone but specify particular IPv4 or IPv6 addresses  to
                   use.  OVN  IPAM  will  still  automatically  allocate  the  other  address  if
                   configured appropriately. Example: dynamic 192.168.0.1 2001::1.

              mac dynamic
                   This acts like dynamic alone but specifies a particular MAC  address  to  use.
                   OVN IPAM will still automatically allocate IPv4 or IPv6 addresses, or both, if
                   configured appropriately. Example: 80:fa:5b:06:72:b7 dynamic

              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 distributed gateway port 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.

       mirror_rules: set of weak reference to Mirrors
              Mirror rules that apply to logical switch port which is the source. Please see  the
              Mirror 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.)

     Tunnel Key:

       options : requested-tnl-key: optional string, containing an integer, in range 1 to 32,767
              Configures the port binding tunnel key for the port. Usually  this  is  not  needed
              because  ovn-northd  will assign an unique key for each port by itself. However, if
              it is configured, ovn-northd honors the configured value. The typical use  case  is
              for  interconnection:  the  tunnel  keys  for  ports on transit switches need to be
              unique globally, so they are maintained in the global  OVN_IC_Southbound  database,
              and ovn-ic simply syncs the value from OVN_IC_Southbound through this config.

     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.

Forwarding_Group TABLE

       Each row represents one forwarding group.

   Summary:
       name                          string
       vip                           string
       vmac                          string
       liveness                      boolean
       child_port                    set of 1 or more strings
       Common Columns:
         external_ids                map of string-string pairs

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

       vip: string
              The  virtual IP address assigned to the forwarding group. It will respond with vmac
              when an ARP request is sent for vip.

       vmac: string
              The virtual MAC address assigned to the forwarding group.

       liveness: boolean
              If set to true, liveness is enabled for child ports otherwise it is disabled.

       child_port: set of 1 or more strings
              List of child ports in the forwarding group.

     Common Columns:

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

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, one of sctp, tcp, or udp
       Health Checks:
         health_check                set of Load_Balancer_Health_Checks
         ip_port_mappings            map of string-string pairs
       selection_fields              set  of  strings,  one  of eth_dst, eth_src, ip_dst, ip_src,
                                     tp_dst, or tp_src
       Common Columns:
         external_ids                map of string-string pairs
       Load_Balancer options:
         options : reject            optional string, either true or false
         options : hairpin_snat_ip   optional string
         options : skip_snat         optional string
         options : add_route         optional string
         options : neighbor_responder
                                     optional string
         options : template          optional string
         options : address-family    optional string
         options : affinity_timeout  optional string
         options : ct_flush          optional string, either true or false

   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, one of sctp, tcp, or udp
              Valid  protocols are tcp, udp, or sctp. 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.

     Health Checks:

       OVN  supports  health  checks for load balancer endpoints. When health checks are enabled,
       the load balancer uses only healthy endpoints.

       Suppose that vips contains a key-value pair  10.0.0.10:80=10.0.0.4:8080,20.0.0.4:8080.  To
       enable   health   checks  for  this  virtual’s  endpoints,  add  two  key-value  pairs  to
       ip_port_mappings, with keys 10.0.0.4 and 20.0.0.4, and add to health_check a reference  to
       a  Load_Balancer_Health_Check  row whose vip is set to 10.0.0.10. The same approach can be
       used for IPv6 as well.

       health_check: set of Load_Balancer_Health_Checks
              Load balancer health checks associated with this load balancer.

       ip_port_mappings: map of string-string pairs
              Maps from endpoint IP to a colon-separated pair of logical port name and source IP,
              e.g.  port_name:sourc_ip  for  IPv4.  Health  checks are sent to this port with the
              specified source IP. For IPv6 square brackets must be used around IP address,  e.g:
              port_name:[sourc_ip]

              For  example,  in  the  example  above,  IP  to  port  mappings might be defined as
              10.0.0.4=sw0-p1:10.0.0.2 and 20.0.0.4=sw1-p1:20.0.0.2, if  the  values  given  were
              suitable ports and IP addresses.

              For IPv6 IP to port mappings might be defined as [2001::1]=sw0-p1:[2002::1].

       selection_fields:  set  of  strings,  one  of eth_dst, eth_src, ip_dst, ip_src, tp_dst, or
       tp_src
              OVN native load balancers are supported using the OpenFlow groups of  type  select.
              OVS  supports  two  selection  methods:  dp_hash  and  hash  (with  optional fields
              specified) in selecting the buckets of a group. Please see  the  OVS  documentation
              (man  ovs-ofctl)  for  more details on the selection methods. Each endpoint IP (and
              port if set) is mapped to a bucket in the group flow.

              CMS can choose the hash selection method by setting the selection  fields  in  this
              column. ovs-vswitchd uses the specified fields in generating the hash.

              dp_hash  selection method uses the assistance of datapath to calculate the hash and
              it is expected to be faster than hash selection method. So  CMS  should  take  this
              into   consideration   before  using  the  hash  method.  Please  consult  the  OVS
              documentation and OVS sources for the implementation details.

     Common Columns:

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

     Load_Balancer options:

       options : reject: optional string, either true or false
              If the load balancer is created with --reject option and it has no active backends,
              a  TCP  reset  segment  (for tcp) or an ICMP port unreachable packet (for all other
              kind of traffic) will be sent whenever an incoming  packet  is  received  for  this
              load-balancer.   Please  note  using  --reject  option  will  disable  empty_lb  SB
              controller event for this load balancer.

       options : hairpin_snat_ip: optional string
              IP to be used as source IP for  packets  that  have  been  hair-pinned  after  load
              balancing.  The  default  behavior  when  the  option is not set is to use the load
              balancer VIP as source IP. This option may have exactly one IPv4  and/or  one  IPv6
              address on it, separated by a space character.

       options : skip_snat: optional string
              If  the  load  balancing  rule  is  configured  with  skip_snat  option, the option
              lb_force_snat_ip configured for  the  logical  router  that  references  this  load
              balancer will not be applied for this load balancer.

       options : add_route: optional string
              If set to true, then neighbor routers will have logical flows added that will allow
              for routing to the VIP IP. It also will have ARP resolution logical flows added. By
              setting    this   option,   it   means   there   is   no   reason   to   create   a
              Logical_Router_Static_Route from neighbor routers to  this  NAT  address.  It  also
              means  that  no  ARP  request  is required for neighbor routers to learn the IP-MAC
              mapping for this VIP IP. For more information about what flows  are  added  for  IP
              routes, please see the ovn-northd manpage section on IP Routing.

       options : neighbor_responder: optional string
              If  set  to  all,  then  routers  on  which  the  load balancer is applied reply to
              ARP/neighbor discovery requests for all VIPs  of  the  load  balancer.  If  set  to
              reachable, then routers on which the load balancer is applied reply to ARP/neighbor
              discovery requests only for VIPs that are part of a  router’s  subnet.  If  set  to
              none,  then  routers  on  which  the  load  balancer  is  applied  never  reply  to
              ARP/neighbor discovery requests for any of the load balancer VIPs.  Load  balancers
              with  options:template=true  do  not support reachable as a valid mode. The default
              value of this option, if not specified, is reachable for regular load balancers and
              none for template load balancers.

       options : template: optional string
              Option  to  be  set  to true, if the load balancer is a template. The load balancer
              VIPs and backends must be using Chassis_Template_Var in their definitions.

              Load balancer template VIP supported formats are:

              ^VIP_VAR[:^PORT_VAR|:port]

              where VIP_VAR and PORT_VAR are keys of the Chassis_Template_Var variables records.

              Note: The VIP and PORT cannot be combined into  a  single  template  variable.  For
              example, a Chassis_Template_Var variable expanding to 10.0.0.1:8080 is not valid if
              used as VIP.

              Load balancer template backend supported formats are:

              ^BACKEND_VAR1[:^PORT_VAR1|:port],^BACKEND_VAR2[:^PORT_VAR2|:port]
              or
              ^BACKENDS_VAR1,^BACKENDS_VAR2

              where  BACKEND_VAR1,  PORT_VAR1,   BACKEND_VAR2,   PORT_VAR2,   BACKENDS_VAR1   and
              BACKENDS_VAR2 are keys of the Chassis_Template_Var variables records.

       options : address-family: optional string
              Address  family  used by the load balancer. Supported values are ipv4 and ipv6. The
              address-family is only used for  load  balancers  with  options:template=true.  For
              explicit load balancers, setting the address-family has no effect.

       options : affinity_timeout: optional string
              If  the  CMS  provides a positive value (in seconds) for affinity_timeout, OVN will
              dnat connections received from the same client to this lb to the  same  backend  if
              received in the affinity timeslot. Max supported affinity_timeout is 65535 seconds.

       options : ct_flush: optional string, either true or false
              The value indicates whether ovn-controller should flush CT entries that are related
              to this LB. The flush happens if  the  LB  is  removed,  any  of  the  backends  is
              updated/removed  or  the  LB is not considered local anymore by the ovn-controller.
              This option is set to false by default.

Load_Balancer_Group TABLE

       Each row represents a logical grouping of load balancers. It is up to the  CMS  to  decide
       the  criteria  on which load balancers are grouped together. To simplify configuration and
       to optimize its processing load balancers that must be  associated  to  the  same  set  of
       logical switches and/or logical routers should be grouped together.

   Summary:
       name                          string (must be unique within table)
       load_balancer                 set of weak reference to Load_Balancers

   Details:
       name: string (must be unique within table)
              A  name  for  the  load balancer group. This name has no special meaning or purpose
              other than to provide convenience for human interaction with the ovn-nb database.

       load_balancer: set of weak reference to Load_Balancers
              A set of load balancers.

Load_Balancer_Health_Check TABLE

       Each row represents one load balancer health check.

   Summary:
       vip                           string
       Health check options:
         options : interval          optional string, containing an integer
         options : timeout           optional string, containing an integer
         options : success_count     optional string, containing an integer
         options : failure_count     optional string, containing an integer
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       vip: string
              vip whose endpoints should be monitored for health check.

     Health check options:

       options : interval: optional string, containing an integer
              The interval, in seconds, between health checks.

       options : timeout: optional string, containing an integer
              The time, in seconds, after which a health check times out.

       options : success_count: optional string, containing an integer
              The number of successful checks after which the endpoint is considered online.

       options : failure_count: optional string, containing an integer
              The number of failure checks after which the endpoint is considered offline.

     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:
       label                         integer, in range 0 to 4,294,967,295
       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-stateless, allow,  drop,
                                     pass, or reject
       tier                          integer, in range 0 to 3
       options:
         options : apply-after-lb    optional string
       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:
         options                     map of string-string pairs
         ACL configuration options:
            options : log-related    optional string
         external_ids                map of string-string pairs

   Details:
       label: integer, in range 0 to 4,294,967,295
              Associates an  identifier  with  the  ACL.  The  same  value  will  be  written  to
              corresponding connection tracker entry. The value should be a valid 32-bit unsigned
              integer. This value can  help  in  debugging  from  connection  tracker  side.  For
              example,  through  this "label" we can backtrack to the ACL rule which is causing a
              "leaked" connection. Connection  tracker  entries  are  created  only  for  allowed
              connections so the label is valid only for allow and allow-related actions.

       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.

              allow-stateless flows always take precedence before stateful  ACLs,  regardless  of
              their priority. (Both allow and allow-related ACLs can be stateful.)

       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-stateless, allow, drop, pass, or reject
              The action to take when the ACL rule matches:

              •      allow-stateless:  Always  forward  the  packet in stateless manner, omitting
                     connection tracking mechanism, regardless of other  rules  defined  for  the
                     switch.  May  require  defining  additional  rules  for inbound replies. For
                     example, if you define a rule to allow outgoing TCP traffic directed  to  an
                     IP  address,  then  you  probably  also want to define another rule to allow
                     incoming TCP traffic coming from this same IP address. In addition,  traffic
                     that   matches   stateless   ACLs  will  bypass  load-balancer  DNAT/un-DNAT
                     processing. Stateful ACLs should be used instead if the traffic is  supposed
                     to be load-balanced.

              •      allow:  Forward the packet. It will also send the packets through connection
                     tracking when allow-related rules exist on the  logical  switch.  Otherwise,
                     it’s equivalent to allow-stateless.

              •      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.

              •      pass:  Pass  to  the  next ACL tier. If using multiple ACL tiers, a match on
                     this ACL will stop evaluating ACLs at the current tier and move to the  next
                     one.  If  not using ACL tiers or if a pass ACL is matched at the final tier,
                     then the options:default_acl_drop option from the NB_Global table is used to
                     determine how to proceed.

       tier: integer, in range 0 to 3
              The hierarchical tier that this ACL belongs to.

              ACLs  can be assigned to numerical tiers. When evaluating ACLs, an internal counter
              is used to determine which tier of ACLs  should  be  evaluated.  Tier  0  ACLs  are
              evaluated  first.  If  no verdict can be determined, then tier 1 ACLs are evaluated
              next. This continues until the maximum tier value is reached. If all tiers of  ACLs
              are  evaluated  and no verdict is reached, then the options:default_acl_drop option
              from table NB_Global is used to determine how to proceed.

              In this version of OVN, the maximum tier value for ACLs is 3, meaning there  are  4
              tiers of ACLs allowed (0-3).

     options:

       ACLs options.

       options : apply-after-lb: optional string
              If  set to true, the ACL will be applied after load balancing stage. Supported only
              for from-lport direction.

              The main use case of this option is to support ACLs matching on the destination  IP
              address of the packet for the backend IPs of load balancers.

              OVN  will  apply  the  from-lport  ACLs  in  two  stages.  ACLs without this option
              apply-after-lb set, will be applied before the load balancer stage  and  ACLs  with
              this  option  set will be applied after the load balancer stage. The priorities are
              indepedent between these stages and may not be obvious to the CMS. Hence CMS should
              be  extra  careful  when  using  this  option  and  should  carefully  evaluate the
              priorities of all the ACLs and the default deny/allow ACLs if any.

     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. In order to ensure that the same  Meter  rate  limits  multiple  ACL  logs
              separately, set the fair column.

     Common Columns:

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

     ACL configuration options:

       options : log-related: optional string
              If set to true, then log when reply or related traffic is admitted from a  stateful
              ACL. In order for this option to function, the log option must be set to true and a
              label must be set, and it must be unique to the ACL. The label is necessary  as  it
              is  the only means to associate the reply traffic with the ACL to which it belongs.
              It must be unique, because otherwise it is ambiguous which  ACL  will  be  matched.
              Note:  If  this  option  is enabled, an extra flow is installed in order to log the
              related traffic. Therefore, if this is enabled on all ACLs, then the  total  number
              of flows necessary to log the ACL traffic is doubled, compared to if this option is
              not enabled.

       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
       load_balancer_group           set of Load_Balancer_Groups
       Naming:
         name                        string
         external_ids : neutron:router_name
                                     optional string
       copp                          optional weak reference to Copp
       Options:
         options : chassis           optional string
         options : dnat_force_snat_ip
                                     optional string
         options : lb_force_snat_ip  optional string
         options : mcast_relay       optional string, either true or false
         options : dynamic_neigh_routers
                                     optional string, either true or false
         options : always_learn_from_arp_request
                                     optional string, either true or false
         options : requested-tnl-key
                                     optional string,  containing  an  integer,  in  range  1  to
                                     16,777,215
         options : snat-ct-zone      optional string, containing an integer, in range 0 to 65,535
         options : mac_binding_age_threshold
                                     optional  string,  containing  an  integer,  in  range  0 to
                                     4,294,967,295
       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 and only one distributed gateway port.

       load_balancer: set of weak reference to Load_Balancers
              Set  of  load  balancers  associated  to  this  logical  router. Load balancer Load
              balancer rules only work on the Gateway routers or routers with one  and  only  one
              distributed gateway port.

       load_balancer_group: set of Load_Balancer_Groups
              Set of load balancers groups associated to this logical router.

     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.

       copp: optional weak reference to Copp
              The  control plane protection policy from table Copp used for metering packets sent
              to ovn-controller from logical ports of this 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 a set of IP addresses 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 set
              of IP addresses. This option may have exactly one IPv4 and/or one IPv6  address  on
              it, separated by a a space.

       options : lb_force_snat_ip: optional string
              If  set,  this  option  can  take  two  possible type of values. Either a set of IP
              addresses or the string value - router_ip.

              If a set of IP addresses are configured, it indicates 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 set of IP  addresses.  This  option  may  have
              exactly one IPv4 and/or one IPv6 address on it, separated by a space character.

              If  it  is  configured  with  the value router_ip, then the load balanced packet is
              SNATed with the IP of router port (attached to the gateway router) selected as  the
              destination after taking the routing decision.

       options : mcast_relay: optional string, either true or false
              Enables/disables  IP  multicast  relay  between  logical  switches connected to the
              logical router. Default: False.

       options : dynamic_neigh_routers: optional string, either true or false
              If set to true, the router will resolve neighbor routers’  MAC  addresses  only  by
              dynamic  ARP/ND,  instead of prepopulating static mappings for all neighbor routers
              in the ARP/ND Resolution stage. This reduces number of flows, but  requires  ARP/ND
              messages  to resolve the IP-MAC bindings when needed. It is false by default. It is
              recommended to set to true when a large number of logical routers are connected  to
              the  same  logical  switch but most of them never need to send traffic between each
              other. By default, ovn-northd does not create mappings to  NAT  and  load  balancer
              addresess.  However,  for  NAT  and load balancer addresses that have the add_route
              option added, ovn-northd will create logical flows that map NAT and  load  balancer
              IP  addresses to the appropriate MAC address. Setting dynamic_neigh_routers to true
              will prevent the automatic creation of these logical flows.

       options : always_learn_from_arp_request: optional string, either true or false
              This option controls the behavior when handling IPv4 ARP  requests  or  IPv6  ND-NS
              packets - whether a dynamic neighbor (MAC binding) entry is added/updated.

              true - Always learn the MAC-IP binding, and add/update the MAC binding entry.

              false  - If there is a MAC binding for that IP and the MAC is different, or, if TPA
              of ARP request belongs to any router port on this router, then update/add that MAC-
              IP binding. Otherwise, don’t update/add entries.

              It  is  true  by  default. It is recommended to set to false when a large number of
              logical routers are connected to the same logical switch but  most  of  them  never
              need  to  send  traffic  between  each other, to reduce the size of the MAC binding
              table.

       options : requested-tnl-key: optional  string,  containing  an  integer,  in  range  1  to
       16,777,215
              Configures  the  datapath  tunnel  key  for  the logical router. This is not needed
              because ovn-northd will assign an unique key for each datapath by itself.  However,
              if it is configured, ovn-northd honors the configured value.

       options : snat-ct-zone: optional string, containing an integer, in range 0 to 65,535
              Use  the  requested conntrack zone for SNAT with this router. This can be useful if
              egress traffic from the host running OVN comes from both  OVN  and  other  sources.
              This way, OVN and the other sources can make use of the same conntrack zone.

       options : mac_binding_age_threshold: optional string, containing an integer, in range 0 to
       4,294,967,295
              MAC binding aging threshold value in seconds. MAC binding  exceeding  this  timeout
              will be automatically removed. The value defaults to 0, which means disabled.

     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  bandwidth  column
       is  specified,  then matching packets will have metering applied. action and bandwidth 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.

Mirror TABLE

       Each  row  in  this  table  represents a mirror that can be used for port mirroring. These
       mirrors are referenced by the mirror_rules column in the Logical_Switch_Port table.

   Summary:
       name                          string (must be unique within table)
       filter                        string, one of both, from-lport, or to-lport
       sink                          string
       type                          string, one of erspan, gre, or local
       index                         integer
       external_ids                  map of string-string pairs

   Details:
       name: string (must be unique within table)
              Represents the name of the mirror.

       filter: string, one of both, from-lport, or to-lport
              The value of this field represents  selection  criteria  of  the  mirror.  to-lport
              mirrors  the packets coming into logical port. from-lport mirrors the packets going
              out of logical port. both mirrors for both directions.

       sink: string
              The value of this field represents the destination/sink of the mirror. If the  type
              is  gre  or erspan, the value indicates the tunnel remote IP (either IPv4 or IPv6).
              For a type of local, this field defines a local interface on  the  OVS  integration
              bridge  to  be used as the mirror destination. The interface must possess external-
              ids:mirror-id that matches this string.

       type: string, one of erspan, gre, or local
              The value of this field specifies the mirror type - gre, erspan or local.

       index: integer
              The value of this field represents the tunnel ID. If the configured tunnel type  is
              gre,  this  field represents the GRE key value and if the configured tunnel type is
              erspan it represents the erspan_idx value. It is ignored if the type is local.

       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
       fair                          optional boolean
       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.

       fair: optional boolean
              This column is used to further describe the desired  behavior  of  the  meter  when
              there  are  multiple  references to it. If this column is empty or is set to false,
              the rate will be shared across  all  rows  that  refer  to  the  same  Meter  name.
              Conversely,  when  this  column is set to true, each user of the same Meter will be
              rate-limited on its own.

       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)
       networks                      set of 1 or more strings
       mac                           string
       enabled                       optional boolean
       Distributed Gateway Ports:
         ha_chassis_group            optional HA_Chassis_Group
         gateway_chassis             set of Gateway_Chassises
         Options for Physical VLAN MTU Issues:
            options : reside-on-redirect-chassis
                                     optional string, either true or false
            options : redirect-type  optional string, either bridged or overlay
       ipv6_prefix                   set of strings
       ipv6_ra_configs:
         ipv6_ra_configs : address_mode
                                     optional string
         ipv6_ra_configs : router_preference
                                     optional string
         ipv6_ra_configs : route_info
                                     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
         ipv6_ra_configs : rdnss     optional string
         ipv6_ra_configs : dnssl     optional string
       Options:
         options : mcast_flood       optional string, either true or false
         options : requested-tnl-key
                                     optional string, containing an integer, in range 1 to 32,767
         options : prefix_delegation
                                     optional string, either true or false
         options : prefix            optional string, either true or false
         options : route_table       optional string
         options : gateway_mtu       optional string, containing  an  integer,  in  range  68  to
                                     65,535
         options : gateway_mtu_bypass
                                     optional string
       Attachment:
         peer                        optional string
       Common Columns:
         external_ids                map of string-string pairs
       Status:
         status : hosting-chassis    optional string

   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.

              A  logical router port may not have the same name as a logical switch port, but the
              database schema cannot enforce this.

       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.

     Distributed Gateway Ports:

       Gateways, as documented under Gateways in the  OVN  architecture  guide,  provide  limited
       connectivity  between  logical  networks  and physical ones. OVN support multiple kinds of
       gateways. The Logical_Router_Port table can  be  used  two  different  ways  to  configure
       distributed gateway ports, which are one kind of gateway. These two forms of configuration
       exist for historical reasons. Both of them produce the same kind of OVN southbound records
       and the same behavior in practice.

       If either of these are set, this logical router port represents a distributed gateway port
       that connects this router to a logical switch with a localnet  port  or  a  connection  to
       another OVN deployment.

       Also  mentioned  in the OVN architecture guide, distributed gateway ports can also be used
       for scalability reasons in deployments where logical switches are dedicated  to  chassises
       rather than distributed.

       The  preferred way to configure a gateway is ha_chassis_group, but gateway_chassis is also
       supported for backward compatibility. Only one of these should be set at a time on a given
       LRP, since they configure the same features.

       Even  when  a  gateway is configured, 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 gateway chassis.

       There  can  be  more than one distributed gateway ports configured on each logical router,
       each connecting to different L2 segments. Load-balancing is not yet supported  on  logical
       routers with more than one distributed gateway ports.

       For  each distributed gateway port, it may have more than one gateway chassises. When more
       than one gateway chassis is specified, OVN only uses one at a time. OVN can  rely  on  OVS
       BFD  implementation  to  monitor  gateway  connectivity,  preferring  the highest-priority
       gateway that is online. Priorities are specified in the priority column of Gateway_Chassis
       or HA_Chassis.

       ovn-northd programs the external_mac rules specified in the LRP’s LR into 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 gateway chasssis. If it is desired to  generate  gratuitous
       ARPs for NAT addresses, then set the peer LSP’s options:nat-addresses to router.

       OVN  20.03  and earlier supported a third way to configure distributed gateway ports using
       options:redirect-chassis to  specify  the  gateway  chassis.  This  method  is  no  longer
       supported.  Any  remaining  users  should  switch  to  one of the newer methods instead. A
       gateway_chassis  may  be  easily  configured  from  the  command  line,   e.g.   ovn-nbctl
       lrp-set-gateway-chassis lrp chassis.

       ha_chassis_group: optional HA_Chassis_Group
              Designates an HA_Chassis_Group to provide gateway high availability.

       gateway_chassis: set of Gateway_Chassises
              Designates one or more Gateway_Chassis for the logical router port.

     Options for Physical VLAN MTU Issues:

       MTU  issues  arise  in mixing tunnels with logical networks that are bridged to a physical
       VLAN. For an explanation of the MTU issues, see  Physical  VLAN  MTU  Issues  in  the  OVN
       architecture  document.  The following options, which are alternatives, provide solutions.
       Both of them cause packets to be sent over localnet instead of tunnels, but they differ in
       whether  some  or all packets are sent this way. The most prominent tradeoff between these
       options is that reside-on-redirect-chassis is easier to configure and  that  redirect-type
       performs better for east-west traffic.

       options : reside-on-redirect-chassis: optional string, either true or false
              If  set  to  true, this option forces all traffic across the logical router port to
              pass through the gateway chassis using a hop across a localnet port.  This  changes
              behavior in two ways:

              •      Without  this  option,  east-west traffic passes directly between source and
                     destination chassis (or even within a single chassis, for  co-located  VMs).
                     With this option, all east-west traffic passes through the gateway chassis.

              •      Without  this  option, traffic between the gateway chassis and other chassis
                     is encapsulated in tunnels. With this option, traffic passes over a localnet
                     interface.

              This  option  may  usefully  be  set  only  on  logical router ports that connect a
              distributed logical router to a logical switch with VIFs. It should not be set on a
              distributed gateway port.

              OVN  honors this option only if the logical router has one and only one distributed
              gateway port and if the LRP’s peer switch has a localnet port.

       options : redirect-type: optional string, either bridged or overlay
              If set to bridged on a distributed gateway port, this option causes OVN to redirect
              packets  to  the  gateway  chassis  over  a  localnet port instead of a tunnel. The
              relevant chassis must share a localnet port.

              This feature requires the administrator or the CMS to configure each  participating
              chassis  with  a  unique  Ethernet  address  for  the  logical  router  by  setting
              ovn-chassis-mac-mappings in the Open vSwitch database, for use by ovn-controller.

              Setting this option to overlay or leaving it unset has no effect. This  option  may
              usefully  be  set only on a distributed gateway port when there is one and only one
              distributed gateway port on the logical router. It is otherwise ignored.

       ipv6_prefix: set of strings
              This column contains IPv6 prefix obtained by prefix delegation router according  to
              RFC 3633

     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 : router_preference: optional string
              Default Router Preference (PRF) indicates whether to prefer this router over  other
              default routers (RFC 4191). Possible values are:

              •      HIGH: mapped to 0x01 in RA PRF field

              •      MEDIUM: mapped to 0x00 in RA PRF field

              •      LOW: mapped to 0x11 in RA PRF field

       ipv6_ra_configs : route_info: optional string
              Route  Info  is  used  to  configure Route Info Option sent in Router Advertisement
              according to RFC 4191. Route Info is a comma  separated  string  where  each  field
              provides  PRF  and prefix for a given route (e.g: HIGH-aef1::11/48,LOW-aef2::11/96)
              Possible PRF values are:

              •      HIGH: mapped to 0x01 in RA PRF field

              •      MEDIUM: mapped to 0x00 in RA PRF field

              •      LOW: mapped to 0x11 in RA PRF field

       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.

       ipv6_ra_configs : rdnss: optional string
              IPv6  address  of  RDNSS server announced in RA packets. At the moment OVN supports
              just one RDNSS server.

       ipv6_ra_configs : dnssl: optional string
              DNS Search List announced in RA packets. Multiple DNS Search List must  be  ’comma’
              separated (e.g. "a.b.c, d.e.f")

     Options:

       Additional options for the logical router port.

       options : mcast_flood: optional string, either true or false
              If set to true, multicast traffic (including reports) are unconditionally forwarded
              to the specific port.

              This option  applies  when  the  port  is  part  of  a  logical  router  which  has
              options:mcast_relay set to true.

              Default: false.

       options : requested-tnl-key: optional string, containing an integer, in range 1 to 32,767
              Configures  the  port  binding  tunnel key for the port. Usually this is not needed
              because ovn-northd will assign an unique key for each port by itself.  However,  if
              it is configured, ovn-northd honors the configured value.

       options : prefix_delegation: optional string, either true or false
              If  set to true, enable IPv6 prefix delegation state machine on this logical router
              port (RFC3633). IPv6 prefix delegation is available just on a gateway router or  on
              a gateway router port.

       options : prefix: optional string, either true or false
              If set to true, this interface will receive an IPv6 prefix according to RFC3663

       options : route_table: optional string
              Designates  lookup  Logical_Router_Static_Routes  with specified route_table value.
              Routes to directly connected networks from same Logical Router and  routes  without
              route_table  option  set  have  higher priority than routes with route_table option
              set.

       options : gateway_mtu: optional string, containing an integer, in range 68 to 65,535
              If set, logical flows will be added to router pipeline to check packet  length.  If
              packet   length  is  greater  than  the  value  set,  ICMPv4  type  3  (Destination
              Unreachable) code 4 (Fragmentation Needed and Don’t Fragment  was  Set)  or  ICMPv6
              type 2 (Packet Too Big) code 0 (no route to destination) packets will be generated.
              This allows for Path MTU Discovery.

       options : gateway_mtu_bypass: optional string
              When configured, represents a match expression, in  the  same  expression  language
              used  for  the  match  column  in the OVN Southbound database’s Logical_Flow table.
              Packets matching this expression will bypass the length  check  configured  through
              the options:gateway_mtu option.

     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.

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

     Status:

       Additional status about the logical router port.

       status : hosting-chassis: optional string
              This option is populated by ovn-northd.

              When  a  distributed  gateway  port  is  bound  to a location in the OVN Southbound
              database Port_Binding ovn-northd will populate  this  key  with  the  name  of  the
              Chassis that is currently hosting this port.

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.

       When there are ECMP routes, i.e. multiple routes with same prefix and policy, one of  them
       will be selected based on the 5-tuple hashing of the packet header.

   Summary:
       ip_prefix                     string
       policy                        optional string, either dst-ip or src-ip
       nexthop                       string
       output_port                   optional string
       bfd                           optional weak reference to BFD
       route_table                   string
       external_ids : ic-learned-route
                                     optional string
       Common Columns:
         external_ids                map of string-string pairs
       Common options:
         options                     map of string-string pairs
         options : ecmp_symmetric_reply
                                     optional string
         options : origin            optional string

   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 or can be set to discard
              for dropping packets which match the given route.

       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.

       bfd: optional weak reference to BFD
              Reference to BFD row if the route has associated a BFD session

       route_table: string
              Any string to place route to separate routing table. If  Logical  Router  Port  has
              configured value in options:route_table other than empty string, OVN performs route
              lookup for all packets entering Logical Router ingress pipeline from this  port  in
              the following manner:

              •      1.  First lookup among "global" routes: routes without route_table value set
                     and routes to directly connected networks.

              •      2. Next lookup among routes with same  route_table  value  as  specified  in
                     LRP’s options:route_table field.

       external_ids : ic-learned-route: optional string
              ovn-ic populates this key if the route is learned from the global OVN_IC_Southbound
              database. In this case the value will be set to the uuid of the row in Route  table
              of the OVN_IC_Southbound database.

     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 : ecmp_symmetric_reply: optional string
              If true, then new traffic that arrives over this route will have its reply  traffic
              bypass ECMP route selection and will be sent out this route instead. Note that this
              option overrides any rules set in the Logical_Router_policy table. This option only
              works on gateway routers (routers that have options:chassis set).

       options : origin: optional string
              In  case  ovn-interconnection  has been learned this route, it will have its origin
              set: either "connected" or "static". This key is supposed to  be  written  only  by
              ovn-ic  daemon.  ovn-northd  then  checks this value when generating Logical Flows.
              Logical_Router_Static_Route records with same ip_prefix within same Logical  Router
              will have next lookup order based on origin key value:

              1.  connected

              2.  static

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
       nexthops                      set of strings
       options : pkt_mark            optional string
       Common Columns:
         external_ids                map of string-string pairs

   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 or nexthops.

       nexthop: optional string
              Note: This column is deprecated in favor of nexthops.

              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.

       nexthops: set of strings
              Next-hop  ECMP  IP  addresses  for this route. Each IP in the list should be the IP
              address of a connected router port or the IP address of a logical port.

              One IP from the list is selected as next hop.

       options : pkt_mark: optional string
              Marks the packet with the value specified when the router policy  is  applied.  CMS
              can  inspect  this  packet marker and take some decisions if desired. This value is
              not preserved when the packet goes out on the wire.

     Common Columns:

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

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
       external_port_range           string
       logical_ip                    string
       logical_port                  optional string
       allowed_ext_ips               optional Address_Set
       exempted_ext_ips              optional Address_Set
       gateway_port                  optional weak reference to Logical_Router_Port
       options : stateless           optional string
       options : add_route           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 gateway 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.

       external_port_range: string
              L4 source port range

              Range of ports, from which a port number will  be  picked  that  will  replace  the
              source   port  of  to  be  NATed  packet.  This  is  basically  PAT  (port  address
              translation).

              Value  of  the  column  is   in   the   format,   port_lo-port_hi.   For   example:
              external_port_range : "1-30000"

              Valid range of ports is 1-65535.

       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  gateway
              chassis.

       allowed_ext_ips: optional Address_Set
              It  represents Address Set of external ips that NAT rule is applicable to. For SNAT
              type NAT rules, this refers to destination addresses. For DNAT type NAT rules, this
              refers to source addresses.

              This  configuration  overrides  the  default NAT behavior of applying a rule solely
              based on internal IP. Without this configuration, NAT happens  without  considering
              the  external IP (i.e dest/source for snat/dnat type rule). With this configuration
              NAT rule is applied ONLY if external ip is in the input Address Set.

       exempted_ext_ips: optional Address_Set
              It represents Address Set of external ips that NAT rule is NOT applicable  to.  For
              SNAT type NAT rules, this refers to destination addresses. For DNAT type NAT rules,
              this refers to source addresses.

              This configuration overrides the default NAT behavior of  applying  a  rule  solely
              based  on  internal IP. Without this configuration, NAT happens without considering
              the external IP (i.e dest/source for snat/dnat type rule). With this  configuration
              NAT rule is NOT applied if external ip is in the input Address Set.

              If  there are NAT rules in a logical router with overlapping IP prefixes (including
              /32), then usage of exempted_ext_ips should be avoided in  following  scenario.  a.
              SNAT  rule (let us say RULE1) with logical_ip PREFIX/MASK (let us say 50.0.0.0/24).
              b. SNAT rule  (let  us  say  RULE2)  with  logical_ip  PREFIX/MASK+1  (let  us  say
              50.0.0.0/25).  c. Now, if exempted_ext_ips is associated with RULE2, then a logical
              ip which matches both 50.0.0.0/24 and 50.0.0.0/25 may get the RULE2 applied  to  it
              instead of RULE1.

              allowed_ext_ips  and exempted_ext_ips are mutually exclusive to each other. If both
              Address Sets are set for a rule, then the NAT rule is not considered.

       gateway_port: optional weak reference to Logical_Router_Port
              A distributed gateway port in the Logical_Router_Port  table  where  the  NAT  rule
              needs to be applied.

              When  multiple  distributed  gateway  ports  are  configured  on  a Logical_Router,
              applying a NAT rule at each of the distributed gateway ports might not be  desired.
              Consider  the  case where a logical router has 2 distributed gateway port, one with
              networks 50.0.0.10/24 and the other with  networks  60.0.0.10/24.  If  the  logical
              router  has  a  NAT  rule  of  type  snat,  logical_ip  10.1.1.0/24 and external_ip
              50.1.1.20/24, the  rule  needs  to  be  selectively  applied  on  matching  packets
              entering/leaving through the distributed gateway port with networks 50.0.0.10/24.

              When a logical router has multiple distributed gateway ports and this column is not
              set for a NAT rule, then the rule will be applied at the distributed  gateway  port
              which  is  in the same network as the external_ip of the NAT rule, if such a router
              port exists. If logical router has a  single  distributed  gateway  port  and  this
              column  is  not  set  for  a  NAT rule, the rule will be applied at the distributed
              gateway port even if the router port is not in the same network as the  external_ip
              of the NAT rule.

       options : stateless: optional string
              Indicates if a dnat_and_snat rule should lead to connection tracking state or not.

       options : add_route: optional string
              If set to true, then neighbor routers will have logical flows added that will allow
              for routing to the NAT address. It also will  have  ARP  resolution  logical  flows
              added.  By  setting  this  option,  it  means  there  is  no  reason  to  create  a
              Logical_Router_Static_Route from neighbor routers to  this  NAT  address.  It  also
              means  that  no  ARP  request  is required for neighbor routers to learn the IP-MAC
              mapping for this NAT address. This option only applies to NATs  of  type  dnat  and
              dnat_and_snat.  For  more  information  about  what  flows are added for IP routes,
              please see the ovn-northd manpage section on IP Routing.

     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 : netbios_name_server
                                     optional string
            options : classless_static_route
                                     optional string
            options : ms_classless_static_route
                                     optional string
            options : next_server    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
            options : arp_cache_timeout
                                     optional string, containing an integer, in range 0 to 255
            options : tcp_keepalive_interval
                                     optional string, containing an integer, in range 0 to 255
            options : netbios_node_type
                                     optional string, containing an integer, in range 0 to 255
         String DHCP Options:
            options : wpad           optional string
            options : bootfile_name  optional string
            options : path_prefix    optional string
            options : tftp_server_address
                                     optional string
            options : hostname       optional string
            options : domain_name    optional string
            options : bootfile_name_alt
                                     optional string
            options : broadcast_address
                                     optional string
         DHCP Options of type host_id:
            options : tftp_server    optional string
          DHCP Options of type domains:
            options : domain_search_list
                                     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
            options : fqdn           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 : netbios_name_server: optional string
              The DHCPv4 option code for this option is 44.

       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.

       options : next_server: optional string
              The DHCPv4 option code for setting the "Next server IP address" field in  the  DHCP
              header.

     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.

       options : arp_cache_timeout: optional string, containing an integer, in range 0 to 255
              The  DHCPv4 option code for this option is 35. This option specifies the timeout in
              seconds for ARP cache entries.

       options : tcp_keepalive_interval: optional string, containing an integer, in  range  0  to
       255
              The  DHCPv4  option  code for this option is 38. This option specifies the interval
              that the client TCP should wait  before  sending  a  keepalive  message  on  a  TCP
              connection.

       options : netbios_node_type: optional string, containing an integer, in range 0 to 255
              The DHCPv4 option code for this option is 46.

     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 : hostname: optional string
              The DHCPv4 option code for this option is 12. If set, indicates the  DHCPv4  option
              "Hostname". Alternatively, this option can be configured in options:hostname column
              in table Logical_Switch_Port. If Hostname option value is set in  both  conflicting
              Logical_Switch_Port and DHCP_Options tables, Logical_Switch_Port takes precedence.

       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.

       options : bootfile_name_alt: optional string
              "bootfile_name_alt" option is used to support iPXE. When both  "bootfile_name"  and
              "bootfile_name_alt"  are  provided  by  the  CMS,  "bootfile_name" will be used for
              option  67  if  the  dhcp  request  contains  etherboot  option  (175),   otherwise
              "bootfile_name_alt" will be used.

       options : broadcast_address: optional string
              The  DHCPv4 option code for this option is 28. This option specifies the IP address
              used as a broadcast address.

     DHCP Options of type host_id:

       These options accept either an IPv4 address or a string value.

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

      DHCP Options of type domains:

       These options accept string value which is a comma separated list  of  domain  names.  The
       domain names are encoded based on RFC 1035.

       options : domain_search_list: optional string
              The DHCPv4 option code for this option is 119.

     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.

       options : fqdn: optional string
              The  DHCPv6  option code for this option is 39. If set, indicates the DHCPv6 option
              "FQDN".

     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. For PTR requests, the key-value pair
              can be Reverse IPv4 address.in-addr.arpa and the value DNS domain  name.  For  IPv6
              addresses, the key has to be Reverse IPv6 address.ip6.arpa.

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

              Example:  "4.0.0.10.in-addr.arpa" = "vm1.ovn.org"

       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 a 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.

   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_Chassises
       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_Chassises
              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.

BFD TABLE

       Contains  BFD  parameter  for  ovn-controller BFD configuration. OVN BFD implementation is
       used to provide detection of failures in the path  between  adjacent  forwarding  engines,
       including  the OVN interfaces. OVN BFD provides link status info to OVN northd in order to
       update  logical  flows  according  to  the  status  of  BFD  endpoints.  In  the   current
       implementation  OVN  BFD is used to check next-hop status for ECMP routes. Please note BFD
       table refers to OVN BFD implementation and not to OVS legacy one.

   Summary:
       Configuration:
         logical_port                string
         dst_ip                      string
         min_tx                      optional integer, at least 1
         min_rx                      optional integer
         detect_mult                 optional integer, at least 1
         options                     map of string-string pairs
         external_ids                map of string-string pairs
       Status Reporting:
         status                      optional string, one of admin_down, down, init, or up

   Details:
     Configuration:

       ovn-northd reads configuration from these columns.

       logical_port: string
              OVN logical port when BFD engine is running.

       dst_ip: string
              BFD peer IP address.

       min_tx: optional integer, at least 1
              This is the minimum interval, in milliseconds, that the local system would like  to
              use  when transmitting BFD Control packets, less any jitter applied. The value zero
              is reserved. Default value is 1000 ms.

       min_rx: optional integer
              This is the minimum interval, in milliseconds, between received BFD Control packets
              that  this  system is capable of supporting, less any jitter applied by the sender.
              If this value is zero, the transmitting system does not want the remote  system  to
              send any periodic BFD Control packets.

       detect_mult: optional integer, at least 1
              Detection  time  multiplier.  The  negotiated transmit interval, multiplied by this
              value, provides the Detection Time for the receiving system in  Asynchronous  mode.
              Default value is 5.

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

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

     Status Reporting:

       ovn-northd writes BFD status into these columns.

       status: optional string, one of admin_down, down, init, or up
              BFD port logical states. Possible values are:

              •      admin_downdowninitup

Static_MAC_Binding TABLE

       Each record represents a Static_MAC_Binding entry for a logical router.

   Summary:
       Configuration:
         logical_port                string
         ip                          string
         mac                         string
         override_dynamic_mac        boolean

   Details:
     Configuration:

       ovn-northd reads configuration from these columns and propagates the value to SBDB.

       logical_port: string
              The logical router port for the binding.

       ip: string
              The bound IP address.

       mac: string
              The Ethernet address to which the IP is bound.

       override_dynamic_mac: boolean
              Override dynamically learnt MACs.

Chassis_Template_Var TABLE

       One  record per chassis, each containing a map, variables, between template variable names
       and their value for that specific chassis. A template variable has a name and  potentially
       different  values on different hypervisors in the OVN cluster. For example, two rows, R1 =
       (.chassis=C1, variables={(N: V1)} and R2 = (.chassis=C2,  variables={(N:  V2)}  will  make
       ovn-controller  running on chassis C1 and C2 interpret the token N either as V1 (on C1) or
       as V2 (on C2). Users can refer to template variables from within other logical components,
       e.g.,  within  ACL,  QoS  or  Logical_Router_Policy  matches or from Load_Balancer VIP and
       backend definitions.

       If a template variable is referenced on a chassis for which that variable is  not  defined
       then  ovn-controller  running  on  that  chassis  will  just  interpret it as a raw string
       literal.

   Summary:
       chassis                       string (must be unique within table)
       variables                     map of string-string pairs
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       chassis: string (must be unique within table)
              The chassis this set of variable values applies to.

       variables: map of string-string pairs
              The set of variable values for a given chassis.

     Common Columns:

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