ovn-sb(5)                     Open vSwitch Manual                    ovn-sb(5)



NAME
       ovn-sb - OVN_Southbound database schema

       This  database  holds  logical and physical configuration and state for
       the Open Virtual  Network  (OVN)  system  to  support  virtual  network
       abstraction.  For  an  introduction  to  OVN,  please see ovn-architec
       ture(7).

       The OVN Southbound database sits at the center of the OVN architecture.
       It is the one component that speaks both southbound directly to all the
       hypervisors and gateways, via  ovn-controller/ovn-controller-vtep,  and
       northbound to the Cloud Management System, via ovn-northd:

   Database Structure
       The  OVN  Southbound  database  contains classes of data with different
       properties, as described in the sections below.

     Physical network

       Physical network tables contain information about the chassis nodes  in
       the  system.  This  contains  all the information necessary to wire the
       overlay, such as IP addresses, supported  tunnel  types,  and  security
       keys.

       The  amount  of  physical  network data is small (O(n) in the number of
       chassis) and it changes infrequently, so it can be replicated to  every
       chassis.

       The Chassis and Encap tables are the physical network tables.

     Logical Network

       Logical  network  tables  contain  the topology of logical switches and
       routers, ACLs, firewall rules, and everything needed  to  describe  how
       packets  traverse  a  logical  network, represented as logical datapath
       flows (see Logical Datapath Flows, below).

       Logical network data may be large (O(n) in the number of logical ports,
       ACL rules, etc.). Thus, to improve scaling, each chassis should receive
       only data related to logical networks in which  that  chassis  partici‐
       pates.

       The  logical network data is ultimately controlled by the cloud manage‐
       ment system (CMS) running northbound of OVN. That  CMS  determines  the
       entire OVN logical configuration and therefore the logical network data
       at any given time is a deterministic function of the  CMS’s  configura‐
       tion,  although that happens indirectly via the OVN_Northbound database
       and ovn-northd.

       Logical network data is likely to change  more  quickly  than  physical
       network  data. This is especially true in a container environment where
       containers are created  and  destroyed  (and  therefore  added  to  and
       deleted from logical switches) quickly.

       The   Logical_Flow,   Multicast_Group,   Address_Group,   DHCP_Options,
       DHCPv6_Options, and DNS tables contain logical network data.

     Logical-physical bindings

       These tables link logical and physical components. They show  the  cur‐
       rent  placement of logical components (such as VMs and VIFs) onto chas‐
       sis, and map logical entities to the values that represent them in tun‐
       nel encapsulations.

       These  tables  change frequently, at least every time a VM powers up or
       down or migrates, and especially quickly in  a  container  environment.
       The amount of data per VM (or VIF) is small.

       Each  chassis  is authoritative about the VMs and VIFs that it hosts at
       any given time and can efficiently flood that state to a central  loca‐
       tion, so the consistency needs are minimal.

       The Port_Binding and Datapath_Binding tables contain binding data.

     MAC bindings

       The MAC_Binding table tracks the bindings from IP addresses to Ethernet
       addresses that are dynamically discovered  using  ARP  (for  IPv4)  and
       neighbor  discovery (for IPv6). Usually, IP-to-MAC bindings for virtual
       machines are statically  populated  into  the  Port_Binding  table,  so
       MAC_Binding  is  primarily  used  to discover bindings on physical net‐
       works.

   Common Columns
       Some tables contain a special column named  external_ids.  This  column
       has  the  same  form  and  purpose  each  place  that it appears, so we
       describe it here to save space later.

              external_ids: map of string-string pairs
                     Key-value pairs for use by the software that manages  the
                     OVN   Southbound   database   rather   than  by  ovn-con
                     troller/ovn-controller-vtep.  In  particular,  ovn-northd
                     can use key-value pairs in this column to relate entities
                     in the southbound database to higher-level entities (such
                     as  entities  in the OVN Northbound database). Individual
                     key-value pairs in this column may be documented in  some
                     cases  to  aid  in understanding and troubleshooting, but
                     the reader should not mistake such documentation as  com‐
                     prehensive.

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

       Table     Purpose
       SB_Global Southbound configuration
       Chassis   Physical Network Hypervisor and Gateway Information
       Encap     Encapsulation Types
       Address_Set
                 Address Sets
       Port_Group
                 Port Groups
       Logical_Flow
                 Logical Network Flows
       Multicast_Group
                 Logical Port Multicast Groups
       Meter     Meter entry
       Meter_Band
                 Band for meter entries
       Datapath_Binding
                 Physical-Logical Datapath Bindings
       Port_Binding
                 Physical-Logical Port Bindings
       MAC_Binding
                 IP to MAC bindings
       DHCP_Options
                 DHCP Options supported by native OVN DHCP
       DHCPv6_Options
                 DHCPv6 Options supported by native OVN DHCPv6
       Connection
                 OVSDB client connections.
       SSL       SSL configuration.
       DNS       Native DNS resolution
       RBAC_Role RBAC_Role configuration.
       RBAC_Permission
                 RBAC_Permission configuration.
       Gateway_Chassis
                 Gateway_Chassis configuration.
       HA_Chassis
                 HA_Chassis configuration.
       HA_Chassis_Group
                 HA_Chassis_Group configuration.
       Controller_Event
                 Controller Event table
       IP_Multicast
                 IP_Multicast configuration.
       IGMP_Group
                 IGMP_Group configuration.
       Service_Monitor
                 Service_Monitor configuration.

SB_Global TABLE
       Southbound  configuration  for  an  OVN  system.  This  table must have
       exactly one row.

   Summary:
       Status:
         nb_cfg                      integer
       Common Columns:
         external_ids                map of string-string pairs
         options                     map of string-string pairs
       Common options:
         options                     map of string-string pairs
         Options for configuring BFD:
            options : bfd-min-rx     optional string
            options : bfd-decay-min-rx
                                     optional string
            options : bfd-min-tx     optional string
            options : bfd-mult       optional string
       Connection Options:
         connections                 set of Connections
         ssl                         optional SSL
       Security Configurations:
         ipsec                       boolean

   Details:
     Status:

       This column allow a client to track the overall configuration state  of
       the system.

       nb_cfg: integer
              Sequence  number  for the configuration. When a CMS or ovn-nbctl
              updates the northbound database, it increments the nb_cfg column
              in the NB_Global table in the northbound database. In turn, when
              ovn-northd updates the southbound database to  bring  it  up  to
              date  with  these  changes,  it  updates this column to the same
              value.

     Common Columns:

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

       options: map of string-string pairs

     Common options:

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

     Options for configuring BFD:

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

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

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

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

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

     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  Connec
              tion 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.
Chassis TABLE
       Each row in this table represents a hypervisor or gateway  (a  chassis)
       in  the  physical  network.  Each  chassis, via ovn-controller/ovn-con
       troller-vtep, adds and updates its own row, and keeps  a  copy  of  the
       remaining rows to determine how to reach other hypervisors.

       When  a  chassis  shuts  down gracefully, it should remove its own row.
       (This is not critical because  resources  hosted  on  the  chassis  are
       equally  unreachable  regardless  of  whether the row is present.) If a
       chassis shuts down permanently without removing its row, some  kind  of
       manual  or  automatic  cleanup  is  eventually  needed; we can devise a
       process for that as necessary.

   Summary:
       name                          string (must be unique within table)
       hostname                      string
       nb_cfg                        integer
       external_ids : ovn-bridge-mappings
                                     optional string
       external_ids : datapath-type  optional string
       external_ids : iface-types    optional string
       external_ids : ovn-cms-options
                                     optional string
       external_ids : is-interconn   optional string
       external_ids : is-remote      optional string
       transport_zones               set of strings
       external_ids : ovn-chassis-mac-mappings
                                     optional string
       Common Columns:
         external_ids                map of string-string pairs
       Encapsulation Configuration:
         encaps                      set of 1 or more Encaps
       Gateway Configuration:
         vtep_logical_switches       set of strings

   Details:
       name: string (must be unique within table)
              OVN does not prescribe a particular format  for  chassis  names.
              ovn-controller  populates this column using external_ids:system-
              id in the Open_vSwitch database’s Open_vSwitch  table.  ovn-con‐
              troller-vtep  populates  this  column  with  name  in  the hard‐
              ware_vtep database’s Physical_Switch table.

       hostname: string
              The hostname of the chassis, if applicable. ovn-controller  will
              populate this column with the hostname of the host it is running
              on. ovn-controller-vtep will leave this column empty.

       nb_cfg: integer
              Sequence  number  for  the  configuration.  When  ovn-controller
              updates  the configuration of a chassis from the contents of the
              southbound database, it copies nb_cfg from the  SB_Global  table
              into this column.

       external_ids : ovn-bridge-mappings: optional string
              ovn-controller  populates  this  key with the set of bridge map‐
              pings it has been configured to use. Other  applications  should
              treat  this  key  as  read-only.  See ovn-controller(8) for more
              information.

       external_ids : datapath-type: optional string
              ovn-controller populates this key with the datapath type config‐
              ured  in the datapath_type column of the Open_vSwitch database’s
              Bridge table. Other applications should treat this key as  read-
              only. See ovn-controller(8) for more information.

       external_ids : iface-types: optional string
              ovn-controller  populates this key with the interface types con‐
              figured in the iface_types column of the Open_vSwitch database’s
              Open_vSwitch  table. Other applications should treat this key as
              read-only. See ovn-controller(8) for more information.

       external_ids : ovn-cms-options: optional string
              ovn-controller populates this key with the set of  options  con‐
              figured   in  the  external_ids:ovn-cms-options  column  of  the
              Open_vSwitch  database’s  Open_vSwitch   table.   See   ovn-con
              troller(8) for more information.

       external_ids : is-interconn: optional string
              ovn-controller populates this key with the setting configured in
              the external_ids:ovn-is-interconn  column  of  the  Open_vSwitch
              database’s  Open_vSwitch  table.  If set to true, the chassis is
              used as an interconnection gateway.  See  ovn-controller(8)  for
              more information.

       external_ids : is-remote: optional string
              ovn-ic  set  this key to true for remote interconnection gateway
              chassises learned from the interconnection southbound  database.
              See ovn-ic(8) for more information.

       transport_zones: set of strings
              ovn-controller  populates this key with the transport zones con‐
              figured in the external_ids:ovn-transport-zones  column  of  the
              Open_vSwitch   database’s   Open_vSwitch   table.  See  ovn-con
              troller(8) for more information.

       external_ids : ovn-chassis-mac-mappings: optional string
              ovn-controller populates this key with the set of  options  con‐
              figured  in  the external_ids:ovn-chassis-mac-mappings column of
              the Open_vSwitch database’s  Open_vSwitch  table.  See  ovn-con
              troller(8) for more information.

     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

     Encapsulation Configuration:

       OVN uses encapsulation to transmit logical  dataplane  packets  between
       chassis.

       encaps: set of 1 or more Encaps
              Points  to  supported  encapsulation  configurations to transmit
              logical dataplane packets to this chassis. Each entry is a Encap
              record that describes the configuration.

     Gateway Configuration:

       A  gateway  is  a chassis that forwards traffic between the OVN-managed
       part of a logical network and a physical VLAN, extending a tunnel-based
       logical  network  into a physical network. Gateways are typically dedi‐
       cated nodes that do not host VMs and will  be  controlled  by  ovn-con
       troller-vtep.

       vtep_logical_switches: set of strings
              Stores  all  VTEP logical switch names connected by this gateway
              chassis. The Port_Binding table entry  with  options:vtep-physi
              cal-switch  equal  Chassis name, and options:vtep-logical-switch
              value in Chassis vtep_logical_switches, will be associated  with
              this Chassis.

Encap TABLE
       The  encaps column in the Chassis table refers to rows in this table to
       identify how OVN may transmit logical dataplane packets to  this  chas‐
       sis.  Each  chassis,  via  ovn-controller(8) or ovn-controller-vtep(8),
       adds and updates its own rows and keeps a copy of the remaining rows to
       determine how to reach other chassis.

   Summary:
       type                          string, one of geneve, stt, or vxlan
       options                       map of string-string pairs
       options : csum                optional string, either true or false
       options : dst_port            optional string, containing an integer
       ip                            string
       chassis_name                  string

   Details:
       type: string, one of geneve, stt, or vxlan
              The  encapsulation  to  use to transmit packets to this chassis.
              Hypervisors must use either geneve  or  stt.  Gateways  may  use
              vxlan, geneve, or stt.

       options: map of string-string pairs
              Options  for  configuring  the  encapsulation, which may be type
              specific.

       options : csum: optional string, either true or false
              csum indicates whether this chassis  can  transmit  and  receive
              packets  that  include checksums with reasonable performance. It
              hints to senders transmitting data to  this  chassis  that  they
              should  use  checksums  to  protect OVN metadata. ovn-controller
              populates this key with the value defined  in  external_ids:ovn-
              encap-csum  column  of  the Open_vSwitch database’s Open_vSwitch
              table. Other applications should treat this  key  as  read-only.
              See ovn-controller(8) for more information.

              In  terms  of  performance,  checksumming actually significantly
              increases throughput in most common cases when running on  Linux
              based  hosts without NICs supporting encapsulation hardware off‐
              load (around 60% for bulk traffic). The reason is that generally
              all  NICs  are  capable  of  offloading transmitted and received
              TCP/UDP checksums (viewed as ordinary data packets  and  not  as
              tunnels).  The benefit comes on the receive side where the vali‐
              dated outer checksum can be used  to  additionally  validate  an
              inner  checksum  (such as TCP), which in turn allows aggregation
              of packets to be more efficiently handled by  the  rest  of  the
              stack.

              Not  all  devices see such a benefit. The most notable exception
              is hardware VTEPs. These devices  are  designed  to  not  buffer
              entire  packets  in  their  switching  engines and are therefore
              unable to efficiently compute or validate full packet checksums.
              In addition certain versions of the Linux kernel are not able to
              fully take advantage of encapsulation NIC offloads in the  pres‐
              ence of checksums. (This is actually a pretty narrow corner case
              though: earlier versions of Linux  don’t  support  encapsulation
              offloads  at  all  and  later versions support both offloads and
              checksums well.)

              csum defaults to false for hardware VTEPs and true for all other
              cases.

              This option applies to geneve and vxlan encapsulations.

       options : dst_port: optional string, containing an integer
              If  set,  overrides  the  UDP (for geneve and vxlan) or TCP (for
              stt) destination port.

       ip: string
              The IPv4 address of the encapsulation tunnel endpoint.

       chassis_name: string
              The name of the chassis that created this encap.

Address_Set TABLE
       This table contains address sets synced from the Address_Set  table  in
       the  OVN_Northbound  database  and  address  sets  generated  from  the
       Port_Group table in the OVN_Northbound database.

       See the documentation for the Address_Set table and Port_Group table in
       the OVN_Northbound database for details.

   Summary:
       name                          string (must be unique within table)
       addresses                     set of strings

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

       addresses: set of strings

Port_Group TABLE
       This  table  contains  names  for  the  logical  switch  ports  in  the
       OVN_Northbound database that belongs to the same group that is  defined
       in Port_Group in the OVN_Northbound database.

   Summary:
       name                          string (must be unique within table)
       ports                         set of strings

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

       ports: set of strings

Logical_Flow TABLE
       Each  row  in  this table represents one logical flow. ovn-northd popu‐
       lates this table with logical  flows  that  implement  the  L2  and  L3
       topologies  specified  in the OVN_Northbound database. Each hypervisor,
       via ovn-controller, translates the logical flows  into  OpenFlow  flows
       specific to its hypervisor and installs them into Open vSwitch.

       Logical  flows are expressed in an OVN-specific format, described here.
       A logical datapath flow is much like an OpenFlow flow, except that  the
       flows  are  written  in  terms  of  logical ports and logical datapaths
       instead of physical ports and physical datapaths.  Translation  between
       logical  and  physical  flows helps to ensure isolation between logical
       datapaths. (The logical flow abstraction also allows the  OVN  central‐
       ized  components  to do less work, since they do not have to separately
       compute and push out physical flows to each chassis.)

       The default action when no flow matches is to drop packets.

       Architectural Logical Life Cycle of a Packet

       This following description focuses  on  the  life  cycle  of  a  packet
       through  a logical datapath, ignoring physical details of the implemen‐
       tation. Please refer to Architectural Physical Life Cycle of  a  Packet
       in ovn-architecture(7) for the physical information.

       The  description here is written as if OVN itself executes these steps,
       but in fact OVN (that is, ovn-controller) programs  Open  vSwitch,  via
       OpenFlow and OVSDB, to execute them on its behalf.

       At  a high level, OVN passes each packet through the logical datapath’s
       logical ingress pipeline, which may output the packet to  one  or  more
       logical  port or logical multicast groups. For each such logical output
       port, OVN passes the packet through the datapath’s logical egress pipe‐
       line,  which  may  either drop the packet or deliver it to the destina‐
       tion. Between the two pipelines, outputs to  logical  multicast  groups
       are  expanded into logical ports, so that the egress pipeline only pro‐
       cesses a single logical output port at a time. Between  the  two  pipe‐
       lines  is  also  where,  when necessary, OVN encapsulates a packet in a
       tunnel (or tunnels) to transmit to remote hypervisors.

       In more detail, to start, OVN searches the Logical_Flow table for a row
       with  correct logical_datapath, a pipeline of ingress, a table_id of 0,
       and a match that is true for the packet. If none is  found,  OVN  drops
       the  packet.  If OVN finds more than one, it chooses the match with the
       highest priority. Then OVN executes each of the  actions  specified  in
       the row’s actions column, in the order specified. Some actions, such as
       those to modify packet headers, require no further  details.  The  next
       and output actions are special.

       The  next  action  causes the above process to be repeated recursively,
       except that OVN searches for table_id of 1 instead of 0. Similarly, any
       next  action  in a row found in that table would cause a further search
       for a table_id of 2, and so on. When  recursive  processing  completes,
       flow control returns to the action following next.

       The  output action also introduces recursion. Its effect depends on the
       current value of the outport field. Suppose outport designates a  logi‐
       cal  port. First, OVN compares inport to outport; if they are equal, it
       treats the output as a no-op by default. In the common case, where they
       are  different,  the packet enters the egress pipeline. This transition
       to the egress pipeline discards register data, e.g. reg0 ...  reg9  and
       connection  tracking  state,  to achieve uniform behavior regardless of
       whether the egress pipeline is on a different hypervisor (because  reg‐
       isters aren’t preserve across tunnel encapsulation).

       To execute the egress pipeline, OVN again searches the Logical_Flow ta‐
       ble for a row with correct logical_datapath, a table_id of 0,  a  match
       that  is true for the packet, but now looking for a pipeline of egress.
       If no matching row is found, the output becomes a no-op. Otherwise, OVN
       executes the actions for the matching flow (which is chosen from multi‐
       ple, if necessary, as already described).

       In the egress pipeline, the next  action  acts  as  already  described,
       except  that  it,  of  course,  searches  for  egress flows. The output
       action, however, now directly outputs the packet  to  the  output  port
       (which  is  now  fixed,  because outport is read-only within the egress
       pipeline).

       The description earlier assumed that  outport  referred  to  a  logical
       port.  If  it  instead  designates  a logical multicast group, then the
       description above still applies, with the addition of fan-out from  the
       logical  multicast  group  to  each logical port in the group. For each
       member of the group, OVN executes the logical  pipeline  as  described,
       with the logical output port replaced by the group member.

       Pipeline Stages

       ovn-northd  populates  the  Logical_Flow  table  with the logical flows
       described in detail in ovn-northd(8).

   Summary:
       logical_datapath              Datapath_Binding
       pipeline                      string, either egress or ingress
       table_id                      integer, in range 0 to 23
       priority                      integer, in range 0 to 65,535
       match                         string
       actions                       string
       external_ids : stage-name     optional string
       external_ids : stage-hint     optional string, containing an uuid
       external_ids : source         optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       logical_datapath: Datapath_Binding
              The logical datapath to which the logical flow belongs.

       pipeline: string, either egress or ingress
              The primary flows used for deciding on  a  packet’s  destination
              are the ingress flows. The egress flows implement ACLs. See Log
              ical Life Cycle of a Packet, above, for details.

       table_id: integer, in range 0 to 23
              The stage in the logical pipeline, analogous to an OpenFlow  ta‐
              ble number.

       priority: integer, in range 0 to 65,535
              The flow’s priority. Flows with numerically higher priority take
              precedence over those with lower. If two logical datapath  flows
              with the same priority both match, then the one actually applied
              to the packet is undefined.

       match: string
              A matching expression.  OVN  provides  a  superset  of  OpenFlow
              matching capabilities, using a syntax similar to Boolean expres‐
              sions in a programming language.

              The most important components of match  expression  are  compar
              isons   between   symbols   and   constants,   e.g.  ip4.dst  ==
              192.168.0.1, ip.proto == 6, arp.op == 1, eth.type == 0x800.  The
              logical  AND  operator &&&& and logical OR operator || can combine
              comparisons into a larger expression.

              Matching expressions also support parentheses for grouping,  the
              logical  NOT  prefix operator !, and literals 0 and 1 to express
              ``false’’ or ``true,’’ respectively. The  latter  is  useful  by
              itself as a catch-all expression that matches every packet.

              Match  expressions  also  support a kind of function syntax. The
              following functions are supported:

              is_chassis_resident(lport)
                     Evaluates to true on a  chassis  on  which  logical  port
                     lport  (a quoted string) resides, and to false elsewhere.
                     This function was introduced in OVN 2.7.

              Symbols

              Type. Symbols have integer or string type. Integer symbols  have
              a width in bits.

              Kinds. There are three kinds of symbols:

              ·      Fields.  A  field  symbol  represents  a packet header or
                     metadata field. For example, a field named vlan.tci might
                     represent the VLAN TCI field in a packet.

                     A  field  symbol can have integer or string type. Integer
                     fields can be nominal or ordinal (see Level  of  Measure
                     ment, below).

              ·      Subfields.  A subfield represents a subset of bits from a
                     larger field. For example,  a  field  vlan.vid  might  be
                     defined  as  an  alias for vlan.tci[0..11]. Subfields are
                     provided for syntactic convenience, because it is  always
                     possible  to  instead  refer  to  a subset of bits from a
                     field directly.

                     Only ordinal fields (see Level of Measurement, below) may
                     have subfields. Subfields are always ordinal.

              ·      Predicates.  A  predicate  is  shorthand  for  a  Boolean
                     expression.  Predicates  may  be  used  much  like  1-bit
                     fields.  For  example,  ip4  might  expand to eth.type ==
                     0x800. Predicates are provided for syntactic convenience,
                     because  it  is  always  possible  to instead specify the
                     underlying expression directly.

                     A predicate whose expansion refers to any  nominal  field
                     or  predicate  (see Level of Measurement, below) is nomi‐
                     nal; other predicates have Boolean level of measurement.

              Level              of              Measurement.              See
              http://en.wikipedia.org/wiki/Level_of_measurement  for  the sta‐
              tistical concept on which this classification  is  based.  There
              are three levels:

              ·      Ordinal.  In statistics, ordinal values can be ordered on
                     a scale. OVN considers a field (or subfield) to be  ordi‐
                     nal  if  its  bits  can be examined individually. This is
                     true for  the  OpenFlow  fields  that  OpenFlow  or  Open
                     vSwitch makes ``maskable.’’

                     Any  use of a ordinal field may specify a single bit or a
                     range of bits, e.g. vlan.tci[13..15] refers  to  the  PCP
                     field  within the VLAN TCI, and eth.dst[40] refers to the
                     multicast bit in the Ethernet destination address.

                     OVN supports all the usual arithmetic relations (==,  !=,
                     =, >gt;>gt;, and >gt;>gt;=) on ordinal fields and their subfields,
                     because OVN can implement  these  in  OpenFlow  and  Open
                     vSwitch as collections of bitwise tests.

              ·      Nominal. In statistics, nominal values cannot be usefully
                     compared except for equality. This is  true  of  OpenFlow
                     port  numbers, Ethernet types, and IP protocols are exam‐
                     ples: all of these are just  identifiers  assigned  arbi‐
                     trarily  with  no  deeper  meaning.  In OpenFlow and Open
                     vSwitch, bits in these fields generally aren’t  individu‐
                     ally addressable.

                     OVN  only supports arithmetic tests for equality on nomi‐
                     nal fields, because OpenFlow and Open vSwitch provide  no
                     way for a flow to efficiently implement other comparisons
                     on them. (A test for inequality can be sort of built  out
                     of  two flows with different priorities, but OVN matching
                     expressions always generate flows with  a  single  prior‐
                     ity.)

                     String fields are always nominal.

              ·      Boolean.  A nominal field that has only two values, 0 and
                     1, is somewhat exceptional, since it is easy  to  support
                     both  equality  and  inequality  tests  on  such a field:
                     either one can be implemented as a test for 0 or 1.

                     Only predicates (see above) have a Boolean level of  mea‐
                     surement.

                     This isn’t a standard level of measurement.

              Prerequisites.  Any  symbol  can  have  prerequisites, which are
              additional condition implied by the use of the symbol. For exam‐
              ple,  For  example,  icmp4.type  symbol  might have prerequisite
              icmp4, which would cause an expression icmp4.type  ==  0  to  be
              interpreted  as  icmp4.type  ==  0 &&&& icmp4, which would in turn
              expand to icmp4.type == 0 &&&& eth.type == 0x800 &&&& ip4.proto == 1
              (assuming  icmp4 is a predicate defined as suggested under Types
              above).

              Relational operators

              All of the standard relational operators ==, !=, =,  >gt;>gt;,  and
              >gt;>gt;=  are  supported.  Nominal  fields support only == and !=, and
              only in a positive sense when outer ! are  taken  into  account,
              e.g. given string field inport, inport == "eth0" and !(inport !=
              "eth0") are acceptable, but not inport != "eth0".

              The implementation of == (or != when it  is  negated),  is  more
              efficient than that of the other relational operators.

              Constants

              Integer  constants may be expressed in decimal, hexadecimal pre‐
              fixed by 0x, or as dotted-quad IPv4 addresses, IPv6 addresses in
              their  standard  forms, or Ethernet addresses as colon-separated
              hex digits. A constant in any of these forms may be followed  by
              a  slash  and  a second constant (the mask) in the same form, to
              form a masked constant. IPv4 and IPv6  masks  may  be  given  as
              integers, to express CIDR prefixes.

              String  constants have the same syntax as quoted strings in JSON
              (thus, they are Unicode strings).

              Some operators support sets of constants  written  inside  curly
              braces  { ... }. Commas between elements of a set, and after the
              last elements, are optional. With ==, ``field  ==  {  constant1,
              constant2,  ...  }’’ is syntactic sugar for ``field == constant1
              || field == constant2 || .... Similarly, ``field != { constant1,
              constant2,  ...  }’’  is  equivalent  to ``field != constant1 &&&&
              field != constant2 &&&& ...’’.

              You may refer to a set of IPv4, IPv6, or MAC addresses stored in
              the Address_Set table by its name. An Address_Set with a name of
              set1 can be referred to as $set1.

              You may refer to a group of logical switch ports stored  in  the
              Port_Group  table  by  its  name.  An  Port_Group with a name of
              port_group1 can be referred to as @port_group1.

              Additionally, you may refer to the set of addresses belonging to
              a  group  of logical switch ports stored in the Port_Group table
              by its name followed by a suffix ’_ip4’/’_ip6’. The IPv4 address
              set  of  a Port_Group with a name of port_group1 can be referred
              to as $port_group1_ip4, and the IPv6 address  set  of  the  same
              Port_Group can be referred to as $port_group1_ip6

              Miscellaneous

              Comparisons  may  name  the  symbol  or the constant first, e.g.
              tcp.src == 80 and 80 == tcp.src are both acceptable.

              Tests for a range may be expressed using a syntax like  1024  =
              tcp.src  =  49151,  which  is  equivalent to 1024 = tcp.src &&&&
              tcp.src = 49151.

              For a one-bit field or predicate,  a  mention  of  its  name  is
              equivalent  to  symobl  == 1, e.g. vlan.present is equivalent to
              vlan.present == 1. The same is true for one-bit subfields,  e.g.
              vlan.tci[12].  There  is no technical limitation to implementing
              the same for ordinal fields of all widths, but  the  implementa‐
              tion is expensive enough that the syntax parser requires writing
              an explicit  comparison  against  zero  to  make  mistakes  less
              likely,  e.g.  in  tcp.src  !=  0  the  comparison  against 0 is
              required.

              Operator precedence is as shown below, from highest  to  lowest.
              There  are  two  exceptions  where parentheses are required even
              though the table would suggest that they  are  not:  &&&&  and  ||
              require parentheses when used together, and ! requires parenthe‐
              ses when applied to a relational expression. Thus, in  (eth.type
              ==  0x800 || eth.type == 0x86dd) &&&& ip.proto == 6 or !(arp.op ==
              1), the parentheses are mandatory.

              ·      ()

              ·      ==   !=   =   >gt;>gt;   >gt;>gt;=

              ·      !

              ·      &&&&   ||

              Comments may be introduced by //, which extends to the next new-
              line. Comments within a line may be bracketed by /* and */. Mul‐
              tiline comments are not supported.

              Symbols

              Most of the symbols below have integer  type.  Only  inport  and
              outport have string type. inport names a logical port. Thus, its
              value is a logical_port name from the Port_Binding  table.  out
              port  may name a logical port, as inport, or a logical multicast
              group defined in the Multicast_Group table.  For  both  symbols,
              only names within the flow’s logical datapath may be used.

              The  regX  symbols  are  32-bit integers. The xxregX symbols are
              128-bit integers, which overlay four of  the  32-bit  registers:
              xxreg0 overlays reg0 through reg3, with reg0 supplying the most-
              significant bits of xxreg0 and reg3 the least-signficant. xxreg1
              similarly overlays reg4 through reg7.

              ·      reg0...reg9

              ·      xxreg0 xxreg1

              ·      inport outport

              ·      flags.loopback

              ·      eth.src eth.dst eth.type

              ·      vlan.tci vlan.vid vlan.pcp vlan.present

              ·      ip.proto ip.dscp ip.ecn ip.ttl ip.frag

              ·      ip4.src ip4.dst

              ·      ip6.src ip6.dst ip6.label

              ·      arp.op arp.spa arp.tpa arp.sha arp.tha

              ·      tcp.src tcp.dst tcp.flags

              ·      udp.src udp.dst

              ·      sctp.src sctp.dst

              ·      icmp4.type icmp4.code

              ·      icmp6.type icmp6.code

              ·      nd.target nd.sll nd.tll

              ·      ct_mark ct_label

              ·      ct_state,   which  has  several  Boolean  subfields.  The
                     ct_next action initializes the following subfields:

                     ·      ct.trk: Always set to true by ct_next to  indicate
                            that  connection  tracking  has  taken  place. All
                            other ct subfields have ct.trk as a prerequisite.

                     ·      ct.new: True for a new flow

                     ·      ct.est: True for an established flow

                     ·      ct.rel: True for a related flow

                     ·      ct.rpl: True for a reply flow

                     ·      ct.inv: True for a connection entry in a bad state

                     The ct_dnat, ct_snat, and ct_lb  actions  initialize  the
                     following subfields:

                     ·      ct.dnat:  True  for  a packet whose destination IP
                            address has been changed.

                     ·      ct.snat: True for a packet whose source IP address
                            has been changed.

              The following predicates are supported:

              ·      eth.bcast expands to eth.dst == ff:ff:ff:ff:ff:ff

              ·      eth.mcast expands to eth.dst[40]

              ·      vlan.present expands to vlan.tci[12]

              ·      ip4 expands to eth.type == 0x800

              ·      ip4.src_mcast expands to ip4.src[28..31] == 0xe

              ·      ip4.mcast expands to ip4.dst[28..31] == 0xe

              ·      ip6 expands to eth.type == 0x86dd

              ·      ip expands to ip4 || ip6

              ·      icmp4 expands to ip4 &&&& ip.proto == 1

              ·      icmp6 expands to ip6 &&&& ip.proto == 58

              ·      icmp expands to icmp4 || icmp6

              ·      ip.is_frag expands to ip.frag[0]

              ·      ip.later_frag expands to ip.frag[1]

              ·      ip.first_frag expands to ip.is_frag &&&& !ip.later_frag

              ·      arp expands to eth.type == 0x806

              ·      nd expands to icmp6.type == {135, 136} &&&& icmp6.code == 0
                     &&&& ip.ttl == 255

              ·      nd_ns expands to icmp6.type == 135 &&&& icmp6.code == 0  &&&&
                     ip.ttl == 255

              ·      nd_na  expands to icmp6.type == 136 &&&& icmp6.code == 0 &&&&
                     ip.ttl == 255

              ·      nd_rs expands to icmp6.type == 133 &&&& icmp6.code == 0  &&&&
                     ip.ttl == 255

              ·      nd_ra  expands to icmp6.type == 134 &&&& icmp6.code == 0 &&&&
                     ip.ttl == 255

              ·      tcp expands to ip.proto == 6

              ·      udp expands to ip.proto == 17

              ·      sctp expands to ip.proto == 132

       actions: string
              Logical datapath actions, to be executed when the  logical  flow
              represented by this row is the highest-priority match.

              Actions share lexical syntax with the match column. An empty set
              of actions (or one that contains just white space or  comments),
              or  a  set  of  actions  that consists of just drop;, causes the
              matched packets to be dropped. Otherwise, the column should con‐
              tain a sequence of actions, each terminated by a semicolon.

              The following actions are defined:

              output;
                     In  the ingress pipeline, this action executes the egress
                     pipeline as a subroutine.  If  outport  names  a  logical
                     port,  the egress pipeline executes once; if it is a mul‐
                     ticast group, the egress pipeline runs once for each log‐
                     ical port in the group.

                     In  the  egress pipeline, this action performs the actual
                     output to the outport logical port. (In the egress  pipe‐
                     line, outport never names a multicast group.)

                     By  default,  output  to  the  input  port  is implicitly
                     dropped, that is, output becomes a no-op  if  outport  ==
                     inport.  Occasionally  it  may be useful to override this
                     behavior, e.g. to send an ARP reply to an ARP request; to
                     do  so,  use  flags.loopback  =  1 to allow the packet to
                     "hair-pin" back to the input port.

              next;
              next(table);
              next(pipeline=pipeline, table=table);
                   Executes the given logical datapath table in pipeline as  a
                   subroutine.  The  default  table  is just after the current
                   one. If pipeline is specified, it may be ingress or egress;
                   the  default  pipeline  is  the  one  currently  executing.
                   Actions in the ingress pipeline may not use  next  to  jump
                   into  the  egress  pipeline  (use  the output instead), but
                   transitions in the opposite direction are allowed.

              field = constant;
                   Sets data or metadata field field to  constant  value  con
                   stant,  e.g.  outport  =  "vif0"; to set the logical output
                   port. To set only a subset of bits in a  field,  specify  a
                   subfield  for  field or a masked constant, e.g. one may use
                   vlan.pcp[2] = 1; or vlan.pcp = 4/4; to set the most sigifi‐
                   cant bit of the VLAN PCP.

                   Assigning  to  a  field  with prerequisites implicitly adds
                   those prerequisites to match; thus,  for  example,  a  flow
                   that  sets tcp.dst applies only to TCP flows, regardless of
                   whether its match mentions any TCP field.

                   Not all fields are modifiable (e.g. eth.type  and  ip.proto
                   are  read-only),  and not all modifiable fields may be par‐
                   tially modified (e.g. ip.ttl must assigned as a whole). The
                   outport field is modifiable in the ingress pipeline but not
                   in the egress pipeline.

              ovn_field = constant;
                   Sets OVN field ovn_field to constant value constant.

                   OVN supports setting the values of certain fields which are
                   not yet supported in OpenFlow to set or modify them.

                   Below are the supported OVN fields:

                   ·      icmp4.frag_mtu

                          This  field  sets the low-order 16 bits of the ICMP4
                          header field that is labelled "unused" in  the  ICMP
                          specification  as  defined  in the RFC 1191 with the
                          value specified in constant.

                          Eg. icmp4.frag_mtu = 1500;

              field1 = field2;
                   Sets data or metadata field field1 to the value of data  or
                   metadata  field field2, e.g. reg0 = ip4.src; copies ip4.src
                   into reg0. To modify only a subset of a field’s bits, spec‐
                   ify  a subfield for field1 or field2 or both, e.g. vlan.pcp
                   = reg0[0..2]; copies the  least-significant  bits  of  reg0
                   into the VLAN PCP.

                   field1 and field2 must be the same type, either both string
                   or both integer fields. If they are  both  integer  fields,
                   they must have the same width.

                   If  field1  or  field2  has  prerequisites,  they are added
                   implicitly to match. It is possible to write an  assignment
                   with   contradictory   prerequisites,  such  as  ip4.src  =
                   ip6.src[0..31];, but the contradiction means that a logical
                   flow with such an assignment will never be matched.

              field1 ->gt;>gt; field2;
                   Similar  to field1 = field2; except that the two values are
                   exchanged instead of copied. Both field1  and  field2  must
                   modifiable.

              ip.ttl--;
                   Decrements the IPv4 or IPv6 TTL. If this would make the TTL
                   zero or negative, then processing of the packet  halts;  no
                   further  actions  are  processed.  (To properly handle such
                   cases, a higher-priority flow should match on ip.ttl == {0,
                   1};.)

                   Prerequisite: ip

              ct_next;
                   Apply   connection   tracking  to  the  flow,  initializing
                   ct_state for matching in later tables. Automatically  moves
                   on to the next table, as if followed by next.

                   As  a  side  effect,  IP  fragments will be reassembled for
                   matching. If a fragmented packet is output, then it will be
                   sent  with  any overlapping fragments squashed. The connec‐
                   tion tracking state is scoped by the logical port when  the
                   action  is used in a flow for a logical switch, so overlap‐
                   ping addresses may be used. To allow traffic related to the
                   matched flow, execute ct_commit . Connection tracking state
                   is scoped by the logical topology when the action  is  used
                   in a flow for a router.

                   It  is  possible  to  have actions follow ct_next, but they
                   will not have access to any of its side-effects and is  not
                   generally useful.

              ct_commit;
              ct_commit(ct_mark=value[/mask]);
              ct_commit(ct_label=value[/mask]);
              ct_commit(ct_mark=value[/mask], ct_label=value[/mask]);
                   Commit the flow to the connection tracking entry associated
                   with   it   by   a   previous   call   to   ct_next.   When
                   ct_mark=value[/mask]  and/or ct_label=value[/mask] are sup‐
                   plied, ct_mark and/or ct_label will be set  to  the  values
                   indicated by value[/mask] on the connection tracking entry.
                   ct_mark is a 32-bit field. ct_label is a 128-bit field. The
                   value[/mask] should be specified in hex string if more than
                   64bits are to be used.

                   Note that if you want processing to continue  in  the  next
                   table,  you  must  execute the next action after ct_commit.
                   You may also leave out next which  will  commit  connection
                   tracking  state,  and  then  drop the packet. This could be
                   useful for setting ct_mark on a connection  tracking  entry
                   before dropping a packet, for example.

              ct_dnat;
              ct_dnat(IP);
                   ct_dnat  sends  the packet through the DNAT zone in connec‐
                   tion tracking table to unDNAT any packet that was DNATed in
                   the  opposite  direction.  The packet is then automatically
                   sent to to the next tables as if followed by next;  action.
                   The  next  tables will see the changes in the packet caused
                   by the connection tracker.

                   ct_dnat(IP) sends the  packet  through  the  DNAT  zone  to
                   change  the destination IP address of the packet to the one
                   provided inside the parentheses and commits the connection.
                   The packet is then automatically sent to the next tables as
                   if followed by next; action. The next tables will  see  the
                   changes in the packet caused by the connection tracker.

              ct_snat;
              ct_snat(IP);
                   ct_snat  sends  the  packet through the SNAT zone to unSNAT
                   any packet that was SNATed in the opposite  direction.  The
                   packet  is automatically sent to the next tables as if fol‐
                   lowed by the next; action. The next  tables  will  see  the
                   changes in the packet caused by the connection tracker.

                   ct_snat(IP)  sends  the  packet  through  the  SNAT zone to
                   change the source IP address of the packet to the one  pro‐
                   vided  inside  the  parenthesis and commits the connection.
                   The packet is then automatically sent to the next tables as
                   if  followed  by next; action. The next tables will see the
                   changes in the packet caused by the connection tracker.

              ct_clear;
                   Clears connection tracking state.

              clone { action; ... };
                   Makes a copy of the packet  being  processed  and  executes
                   each  action  on  the  copy.  Actions  following  the clone
                   action, if any, apply to the original,  unmodified  packet.
                   This  can  be  used  as  a  way to ``save and restore’’ the
                   packet around a set of  actions  that  may  modify  it  and
                   should not persist.

              arp { action; ... };
                   Temporarily  replaces the IPv4 packet being processed by an
                   ARP packet and executes  each  nested  action  on  the  ARP
                   packet.  Actions following the arp action, if any, apply to
                   the original, unmodified packet.

                   The ARP packet that this action operates on is  initialized
                   based on the IPv4 packet being processed, as follows. These
                   are default values that the nested  actions  will  probably
                   want to change:

                   ·      eth.src unchanged

                   ·      eth.dst unchanged

                   ·      eth.type = 0x0806

                   ·      arp.op = 1 (ARP request)

                   ·      arp.sha copied from eth.src

                   ·      arp.spa copied from ip4.src

                   ·      arp.tha = 00:00:00:00:00:00

                   ·      arp.tpa copied from ip4.dst

                   The  ARP packet has the same VLAN header, if any, as the IP
                   packet it replaces.

                   Prerequisite: ip4

              get_arp(P, A);
                   Parameters: logical port string field P, 32-bit IP  address
                   field A.

                   Looks  up A in P’s mac binding table. If an entry is found,
                   stores its Ethernet address in  eth.dst,  otherwise  stores
                   00:00:00:00:00:00 in eth.dst.

                   Example: get_arp(outport, ip4.dst);

              put_arp(P, A, E);
                   Parameters:  logical port string field P, 32-bit IP address
                   field A, 48-bit Ethernet address field E.

                   Adds or updates the entry for IP address A in logical  port
                   P’s mac binding table, setting its Ethernet address to E.

                   Example: put_arp(inport, arp.spa, arp.sha);

              R = lookup_arp(P, A, M);
                   Parameters:  logical port string field P, 32-bit IP address
                   field A, 48-bit MAC address field M.

                   Result: stored to a 1-bit subfield R.

                   Looks up A and M in P’s mac binding table. If an  entry  is
                   found, stores 1 in the 1-bit subfield R, else 0.

                   Example: reg0[0] = lookup_arp(inport, arp.spa, arp.sha);

              nd_ns { action; ... };
                   Temporarily  replaces the IPv6 packet being processed by an
                   IPv6 Neighbor Solicitation packet and executes each  nested
                   action  on  the IPv6 NS packet. Actions following the nd_ns
                   action, if any, apply to the original, unmodified packet.

                   The IPv6 NS packet that this action operates on is initial‐
                   ized  based on the IPv6 packet being processed, as follows.
                   These are default values that the nested actions will prob‐
                   ably want to change:

                   ·      eth.src unchanged

                   ·      eth.dst set to IPv6 multicast MAC address

                   ·      eth.type = 0x86dd

                   ·      ip6.src copied from ip6.src

                   ·      ip6.dst set to IPv6 Solicited-Node multicast address

                   ·      icmp6.type = 135 (Neighbor Solicitation)

                   ·      nd.target copied from ip6.dst

                   The IPv6 NS packet has the same VLAN header, if any, as the
                   IP packet it replaces.

                   Prerequisite: ip6

              nd_na { action; ... };
                   Temporarily replaces the IPv6 neighbor solicitation  packet
                   being  processed  by  an  IPv6  neighbor advertisement (NA)
                   packet and executes each nested action on  the  NA  packet.
                   Actions  following  the  nd_na action, if any, apply to the
                   original, unmodified packet.

                   The NA packet that this action operates on  is  initialized
                   based on the IPv6 packet being processed, as follows. These
                   are default values that the nested  actions  will  probably
                   want to change:

                   ·      eth.dst exchanged with eth.src

                   ·      eth.type = 0x86dd

                   ·      ip6.dst copied from ip6.src

                   ·      ip6.src copied from nd.target

                   ·      icmp6.type = 136 (Neighbor Advertisement)

                   ·      nd.target unchanged

                   ·      nd.sll = 00:00:00:00:00:00

                   ·      nd.tll copied from eth.dst

                   The ND packet has the same VLAN header, if any, as the IPv6
                   packet it replaces.

                   Prerequisite: nd_ns

              nd_na_router { action; ... };
                   Temporarily replaces the IPv6 neighbor solicitation  packet
                   being  processed  by  an  IPv6  neighbor advertisement (NA)
                   packet, sets ND_NSO_ROUTER in the RSO  flags  and  executes
                   each  nested action on the NA packet. Actions following the
                   nd_na_router action, if any, apply to the original, unmodi‐
                   fied packet.

                   The  NA  packet that this action operates on is initialized
                   based on the IPv6 packet being processed, as follows. These
                   are  default  values  that the nested actions will probably
                   want to change:

                   ·      eth.dst exchanged with eth.src

                   ·      eth.type = 0x86dd

                   ·      ip6.dst copied from ip6.src

                   ·      ip6.src copied from nd.target

                   ·      icmp6.type = 136 (Neighbor Advertisement)

                   ·      nd.target unchanged

                   ·      nd.sll = 00:00:00:00:00:00

                   ·      nd.tll copied from eth.dst

                   The ND packet has the same VLAN header, if any, as the IPv6
                   packet it replaces.

                   Prerequisite: nd_ns

              get_nd(P, A);
                   Parameters:  logical  port  string  field  P,  128-bit IPv6
                   address field A.

                   Looks up A in P’s mac binding table. If an entry is  found,
                   stores  its  Ethernet  address in eth.dst, otherwise stores
                   00:00:00:00:00:00 in eth.dst.

                   Example: get_nd(outport, ip6.dst);

              put_nd(P, A, E);
                   Parameters: logical  port  string  field  P,  128-bit  IPv6
                   address field A, 48-bit Ethernet address field E.

                   Adds  or  updates  the  entry for IPv6 address A in logical
                   port P’s mac binding table, setting its Ethernet address to
                   E.

                   Example: put_nd(inport, nd.target, nd.tll);

              R = lookup_nd(P, A, M);
                   Parameters: logical port string field P, 128-bit IP address
                   field A, 48-bit MAC address field M.

                   Result: stored to a 1-bit subfield R.

                   Looks up A and M in P’s mac binding table. If an  entry  is
                   found, stores 1 in the 1-bit subfield R, else 0.

                   Example: reg0[0] = lookup_nd(inport, ip6.src, eth.src);

              R = put_dhcp_opts(D1 = V1, D2 = V2, ..., Dn = Vn);
                   Parameters: one or more DHCP option/value pairs, which must
                   include an offerip option (with code 0).

                   Result: stored to a 1-bit subfield R.

                   Valid only in the ingress pipeline.

                   When this action  is  applied  to  a  DHCP  request  packet
                   (DHCPDISCOVER or DHCPREQUEST), it changes the packet into a
                   DHCP reply (DHCPOFFER or DHCPACK,  respectively),  replaces
                   the  options by those specified as parameters, and stores 1
                   in R.

                   When this action is applied to a non-DHCP packet or a  DHCP
                   packet  that  is not DHCPDISCOVER or DHCPREQUEST, it leaves
                   the packet unchanged and stores 0 in R.

                   The contents of the  DHCP_Option  table  control  the  DHCP
                   option names and values that this action supports.

                   Example: reg0[0] = put_dhcp_opts(offerip = 10.0.0.2, router
                   = 10.0.0.1, netmask = 255.255.255.0, dns_server = {8.8.8.8,
                   7.7.7.7});

              R = put_dhcpv6_opts(D1 = V1, D2 = V2, ..., Dn = Vn);
                   Parameters: one or more DHCPv6 option/value pairs.

                   Result: stored to a 1-bit subfield R.

                   Valid only in the ingress pipeline.

                   When  this action is applied to a DHCPv6 request packet, it
                   changes the  packet  into  a  DHCPv6  reply,  replaces  the
                   options  by  those specified as parameters, and stores 1 in
                   R.

                   When this action is applied to a non-DHCPv6  packet  or  an
                   invalid  DHCPv6  request  packet  ,  it  leaves  the packet
                   unchanged and stores 0 in R.

                   The contents of the DHCPv6_Options table control the DHCPv6
                   option names and values that this action supports.

                   Example:   reg0[3]  =  put_dhcpv6_opts(ia_addr  =  aef0::4,
                   server_id               =                00:00:00:00:10:02,
                   dns_server={ae70::1,ae70::2});

              set_queue(queue_number);
                   Parameters:  Queue  number  queue_number, in the range 0 to
                   61440.

                   This is a logical  equivalent  of  the  OpenFlow  set_queue
                   action. It affects packets that egress a hypervisor through
                   a physical interface. For nonzero queue_number, it  config‐
                   ures  packet  queuing  to match the settings configured for
                   the  Port_Binding  with   options:qdisc_queue_id   matching
                   queue_number.  When queue_number is zero, it resets queuing
                   to the default strategy.

                   Example: set_queue(10);

              ct_lb;
              ct_lb(ip[:port]...);
                   With one or more arguments, ct_lb commits the packet to the
                   connection  tracking  table and DNATs the packet’s destina‐
                   tion IP address (and port) to the IP address  or  addresses
                   (and  optional  ports) specified in the string. If multiple
                   comma-separated IP addresses are specified, each  is  given
                   equal weight for picking the DNAT address. Processing auto‐
                   matically moves on to the next  table,  as  if  next;  were
                   specified,  and  later tables act on the packet as modified
                   by the connection tracker.  Connection  tracking  state  is
                   scoped  by  the  logical  port when the action is used in a
                   flow for a logical switch, so overlapping addresses may  be
                   used.  Connection  tracking  state is scoped by the logical
                   topology when the action is used in a flow for a router.

                   Without arguments, ct_lb sends the packet to the connection
                   tracking table to NAT the packets. If the packet is part of
                   an established connection that was previously committed  to
                   the  connection  tracker  via ct_lb(...), it will automati‐
                   cally get DNATed to the same IP address as the first packet
                   in that connection.

              R = dns_lookup();
                   Parameters: No parameters.

                   Result: stored to a 1-bit subfield R.

                   Valid only in the ingress pipeline.

                   When  this  action is applied to a valid DNS request (a UDP
                   packet typically directed  to  port  53),  it  attempts  to
                   resolve  the  query using the contents of the DNS table. If
                   it is successful, it changes the packet into  a  DNS  reply
                   and  stores  1  in R. If the action is applied to a non-DNS
                   packet, an invalid DNS  request  packet,  or  a  valid  DNS
                   request  for which the DNS table does not supply an answer,
                   it leaves the packet unchanged and stores 0 in R.

                   Regardless of success, the action does not make any of  the
                   changes to the flow that are necessary to direct the packet
                   back to the requester. The logical pipeline  can  implement
                   this behavior with matches and actions in later tables.

                   Example: reg0[3] = dns_lookup();

                   Prerequisite: udp

              R = put_nd_ra_opts(D1 = V1, D2 = V2, ..., Dn = Vn);
                   Parameters:  The  following  IPv6  ND  Router Advertisement
                   option/value pairs as defined in RFC 4861.

                   ·      addr_mode

                          Mandatory parameter which specifies the address mode
                          flag  to  be  set  in the RA flag options field. The
                          value of this option is a string and  the  following
                          values  can  be defined - "slaac", "dhcpv6_stateful"
                          and "dhcpv6_stateless".

                   ·      slla

                          Mandatory parameter which specifies  the  link-layer
                          address  of  the  interface  from  which  the Router
                          Advertisement is sent.

                   ·      mtu

                          Optional parameter which specifies the MTU.

                   ·      prefix

                          Optional parameter which should be specified if  the
                          addr_mode  is  "slaac"  or  "dhcpv6_stateless".  The
                          value should be an IPv6 prefix which  will  be  used
                          for   stateless  IPv6  address  configuration.  This
                          option can be defined multiple times.

                   Result: stored to a 1-bit subfield R.

                   Valid only in the ingress pipeline.

                   When this action is applied to an IPv6 Router  solicitation
                   request  packet,  it changes the packet into an IPv6 Router
                   Advertisement reply and adds the options specified  in  the
                   parameters, and stores 1 in R.

                   When  this action is applied to a non-IPv6 Router solicita‐
                   tion packet or an invalid IPv6 request packet ,  it  leaves
                   the packet unchanged and stores 0 in R.

                   Example: reg0[3] = put_nd_ra_opts(addr_mode = "slaac", slla
                   = 00:00:00:00:10:02, prefix = aef0::/64, mtu = 1450);

              set_meter(rate);
              set_meter(rate, burst);
                   Parameters: rate limit int field rate in kbps,  burst  rate
                   limits int field burst in kbps.

                   This action sets the rate limit for a flow.

                   Example: set_meter(100, 1000);

              R = check_pkt_larger(L)
                   Parameters: packet length L to check for in bytes.

                   Result: stored to a 1-bit subfield R.

                   This    is   a   logical   equivalent   of   the   OpenFlow
                   check_pkt_larger action. If the packet is larger  than  the
                   length specified in L, it stores 1 in the subfield R.

                   Example: reg0[6] = check_pkt_larger(1000);

              log(key=value, ...);
                     Causes  ovn-controller  to  log the packet on the chassis
                     that processes it. Packet logging currently uses the same
                     logging mechanism as other Open vSwitch and OVN messages,
                     which means that whether and where  log  messages  appear
                     depends  on  the  local logging configuration that can be
                     configured with ovs-appctl, etc.

                     The log action takes zero or more of the  following  key-
                     value pair arguments that control what is logged:

                     name=string
                            An  optional  name for the ACL. The string is cur‐
                            rently limited to 64 bytes.

                     severity=level
                            Indicates the severity of the event. The level  is
                            one  of  following  (from  more  to less serious):
                            alert, warning,  notice,  info,  or  debug.  If  a
                            severity is not provided, the default is info.

                     verdict=value
                            The  verdict  for  packets  matching the flow. The
                            value must be one of allow, deny, or reject.

                     meter=string
                            An optional rate-limiting meter to be  applied  to
                            the logs. The string should reference a name entry
                            from the Meter table. The only meter  action  that
                            is appriopriate is drop.

              fwd_group(P);
                     Parameters: liveness, list of child ports P.

                     It  load balances traffic to one or more child ports in a
                     logical switch. ovn-controller translates  the  fwd_group
                     into  openflow group with one bucket for each child port.
                     If liveness is set to true, it also integrates the bucket
                     selection  with BFD status on the tunnel interface corre‐
                     sponding to child port.

                     Example: fwd_group(liveness=true, childports=p1,p2

              icmp4 { action; ... };
              icmp4_error { action; ... };
                   Temporarily replaces the IPv4 packet being processed by  an
                   ICMPv4 packet and executes each nested action on the ICMPv4
                   packet. Actions following these actions, if any,  apply  to
                   the original, unmodified packet.

                   The  ICMPv4  packet  that these actions operates on is ini‐
                   tialized based on the IPv4 packet being processed, as  fol‐
                   lows. These are default values that the nested actions will
                   probably want to  change.  Ethernet  and  IPv4  fields  not
                   listed here are not changed:

                   ·      ip.proto = 1 (ICMPv4)

                   ·      ip.frag = 0 (not a fragment)

                   ·      ip.ttl = 255

                   ·      icmp4.type = 3 (destination unreachable)

                   ·      icmp4.code = 1 (host unreachable)

                   icmp4_error  action  is  expected to be used to generate an
                   ICMPv4 packet in  response  to  an  error  in  original  IP
                   packet.  When  this  action generates the ICMPv4 packet, it
                   also copies the original IP datagram following  the  ICMPv4
                   header as per RFC 1122: 3.2.2.

                   Prerequisite: ip4

              icmp6 { action; ... };
                   Temporarily  replaces the IPv6 packet being processed by an
                   ICMPv6 packet and executes each nested action on the ICMPv6
                   packet.  Actions  following the icmp6 action, if any, apply
                   to the original, unmodified packet.

                   The ICMPv6 packet that this action operates on is  initial‐
                   ized  based on the IPv6 packet being processed, as follows.
                   These are default values that the nested actions will prob‐
                   ably  want  to  change. Ethernet and IPv6 fields not listed
                   here are not changed:

                   ·      ip.proto = 58 (ICMPv6)

                   ·      ip.ttl = 255

                   ·      icmp6.type = 1 (destination unreachable)

                   ·      icmp6.code = 1 (administratively prohibited)

                   Prerequisite: ip6

              tcp_reset;
                   This action transforms the current TCP packet according  to
                   the following pseudocode:

                   if (tcp.ack) {
                           tcp.seq = tcp.ack;
                   } else {
                           tcp.ack = tcp.seq + length(tcp.payload);
                           tcp.seq = 0;
                   }
                   tcp.flags = RST;

                   Then,  the  action  drops all TCP options and payload data,
                   and updates the TCP checksum. IP ttl is set to 255.

                   Prerequisite: tcp

              trigger_event;
                   This action is used to allow  ovs-vswitchd  to  report  CMS
                   related  events  writing them in Controller_Event table. It
                   is possible to associate a meter to a each event  in  order
                   to not overload pinctrl thread under heavy load; each meter
                   is identified though a defined naming convention. Supported
                   events:

                   ·      empty_lb_backends.   This   event  is  raised  if  a
                          received packet is destined for a load balancer  VIP
                          that  has  no  configured  backend destinations. For
                          this event, the event info includes  the  load  bal‐
                          ancer VIP, the load balancer UUID, and the transport
                          protocol. Associated meter: event-elb

              igmp;
                   This action sends the packet to ovn-controller  for  multi‐
                   cast snooping.

                   Prerequisite: igmp

              bind_vport(V, P);
                   Parameters:  logical  port  string field V of type virtual,
                   logical port string field P.

                   Binds the virtual logical port V and sets the chassis  col‐
                   umn  and  virtual_parent  of  the  table Port_Binding. vir
                   tual_parent is set to P.

              handle_svc_check(P);
                   Parameters: logical port string field P.

                   Handles the service monitor reply received from the VIF  of
                   the  logical  port P. ovn-controller periodically sends out
                   the service monitor packets for the services configured  in
                   the  Service_Monitor table and this action updates the sta‐
                   tus of those services.

                   Example: handle_svc_check(inport);

              R = select(N1[=W1], N2[=W2], ...);
                   Parameters: Integer N1, N2..., with optional weight W1, W2,
                   ...

                   Result: stored to a logical field or subfield R.

                   Select  from  a list of integers N1, N2..., each within the
                   range 0 ~ 65535, and store the selected one in the field R.
                   There  must  be  2  or  more  integers listed, each with an
                   optional weight, which is an integer within the range  1  ~
                   65535.  If weight is not specified, it defaults to 100. The
                   selection method is based on the  5-tuple  hash  of  packet
                   header.

                   Processing  automatically moves on to the next table, as if
                   next; were specified. The select action must be put as  the
                   last  action  of  the  logical flow when there are multiple
                   actions (actions put after select will not take effect).

                   Example: reg8[16..31] = select(1=20, 2=30, 3=50);

       external_ids : stage-name: optional string
              Human-readable name for this flow’s stage in the pipeline.

       external_ids : stage-hint: optional string, containing an uuid
              UUID of a OVN_Northbound record that caused this logical flow to
              be  created.  Currently used only for attribute of logical flows
              to northbound ACL records.

       external_ids : source: optional string
              Source file and line number of the code that added this flow  to
              the pipeline.

     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

Multicast_Group TABLE
       The rows in this table define multicast groups of logical ports. Multi‐
       cast groups allow a single packet transmitted over a tunnel to a hyper‐
       visor to be delivered to multiple VMs on that  hypervisor,  which  uses
       bandwidth more efficiently.

       Each  row in this table defines a logical multicast group numbered tun
       nel_key within datapath, whose logical ports are listed  in  the  ports
       column.

   Summary:
       datapath                      Datapath_Binding
       tunnel_key                    integer, in range 32,768 to 65,535
       name                          string
       ports                         set  of  1  or  more  weak  reference  to
                                     Port_Bindings

   Details:
       datapath: Datapath_Binding
              The logical datapath in which the multicast group resides.

       tunnel_key: integer, in range 32,768 to 65,535
              The value used to designate this logical egress port  in  tunnel
              encapsulations.  An index forces the key to be unique within the
              datapath. The unusual range ensures that multicast group IDs  do
              not overlap with logical port IDs.

       name: string
              The  logical multicast group’s name. An index forces the name to
              be unique within the datapath.  Logical  flows  in  the  ingress
              pipeline  may output to the group just as for individual logical
              ports, by assigning the group’s name to outport and executing an
              output action.

              Multicast  group  names  and  logical  port names share a single
              namespace and thus should not overlap (but the  database  schema
              cannot enforce this). To try to avoid conflicts, ovn-northd uses
              names that begin with _MC_.

       ports: set of 1 or more weak reference to Port_Bindings
              The logical ports included in the multicast group. All of  these
              ports must be in the datapath logical datapath (but the database
              schema cannot enforce this).

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

   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.

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

   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 col‐
              umn 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 configura‐
              tion.

Datapath_Binding TABLE
       Each row in this table represents a logical datapath, which  implements
       a logical pipeline among the ports in the Port_Binding table associated
       with it. In practice, the pipeline in a given logical  datapath  imple‐
       ments either a logical switch or a logical router.

       The  main  purpose of a row in this table is provide a physical binding
       for a logical datapath. A logical datapath does  not  have  a  physical
       location,  so  its  physical  binding information is limited: just tun
       nel_key. The rest of the data in this table does not affect packet for‐
       warding.

   Summary:
       tunnel_key                    integer,  in  range 1 to 16,777,215 (must
                                     be unique within table)
       OVN_Northbound Relationship:
         external_ids : logical-switch
                                     optional string, containing an uuid
         external_ids : logical-router
                                     optional string, containing an uuid
         external_ids : interconn-ts
                                     optional string
         Naming:
            external_ids : name      optional string
            external_ids : name2     optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       tunnel_key: integer, in range 1 to 16,777,215 (must  be  unique  within
       table)
              The tunnel key value to which the logical datapath is bound. The
              Tunnel Encapsulation section  in  ovn-architecture(7)  describes
              how  tunnel  keys  are constructed for each supported encapsula‐
              tion.

     OVN_Northbound Relationship:

       Each row in Datapath_Binding is associated with some logical  datapath.
       ovn-northd  uses these keys to track the association of a logical data‐
       path with concepts in the OVN_Northbound database.

       external_ids : logical-switch: optional string, containing an uuid
              For  a  logical  datapath  that  represents  a  logical  switch,
              ovn-northd stores in this key the UUID of the corresponding Log
              ical_Switch row in the OVN_Northbound database.

       external_ids : logical-router: optional string, containing an uuid
              For  a  logical  datapath  that  represents  a  logical  router,
              ovn-northd stores in this key the UUID of the corresponding Log
              ical_Router row in the OVN_Northbound database.

       external_ids : interconn-ts: optional string
              For a logical datapath that represents  a  logical  switch  that
              represents  a  transit  switch  for  interconnection, ovn-northd
              stores in this key the value of the same interconn-ts key of the
              external_ids  column  of the corresponding Logical_Switch row in
              the OVN_Northbound database.

     Naming:

       ovn-northd copies these from the  name  fields  in  the  OVN_Northbound
       database,  either from name and external_ids:neutron:router_name in the
       Logical_Router table or from name and external_ids:neutron:network_name
       in the Logical_Switch table.

       external_ids : name: optional string
              A name for the logical datapath.

       external_ids : name2: optional string
              Another name for the logical datapath.

     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

Port_Binding TABLE
       Each row in this table binds a logical port to a realization. For  most
       logical  ports, this means binding to some physical location, for exam‐
       ple by binding a logical port to a VIF that belongs to a VM running  on
       a  particular  hypervisor.  Other  logical ports, such as logical patch
       ports, can be realized without a specific physical location, but  their
       bindings are still expressed through rows in this table.

       For   every  Logical_Switch_Port  record  in  OVN_Northbound  database,
       ovn-northd creates a record in this  table.  ovn-northd  populates  and
       maintains every column except the chassis column, which it leaves empty
       in new records.

       ovn-controller/ovn-controller-vtep populates the chassis column for the
       records  that identify the logical ports that are located on its hyper‐
       visor/gateway, which ovn-controller/ovn-controller-vtep in  turn  finds
       out  by  monitoring the local hypervisor’s Open_vSwitch database, which
       identifies logical ports via  the  conventions  described  in  Integra
       tionGuide.rst.  (The  exceptions are for Port_Binding records with type
       of l3gateway, whose locations are  identified  by  ovn-northd  via  the
       options:l3gateway-chassis column in this table. ovn-controller is still
       responsible to populate the chassis column.)

       When a chassis shuts down gracefully, it should clean  up  the  chassis
       column  that it previously had populated. (This is not critical because
       resources hosted on the chassis are equally unreachable  regardless  of
       whether  their rows are present.) To handle the case where a VM is shut
       down abruptly on one chassis, then brought up again on a different one,
       ovn-controller/ovn-controller-vtep  must  overwrite  the chassis column
       with new information.

   Summary:
       Core Features:
         datapath                    Datapath_Binding
         logical_port                string (must be unique within table)
         encap                       optional weak reference to Encap
         chassis                     optional weak reference to Chassis
         gateway_chassis             set of Gateway_Chassiss
         ha_chassis_group            optional HA_Chassis_Group
         tunnel_key                  integer, in range 1 to 32,767
         mac                         set of strings
         type                        string
       Patch Options:
         options : peer              optional string
         nat_addresses               set of strings
       L3 Gateway Options:
         options : peer              optional string
         options : l3gateway-chassis
                                     optional string
         options : nat-addresses     optional string
         nat_addresses               set of strings
       Localnet Options:
         options : network_name      optional string
         tag                         optional integer, in range 1 to 4,095
       L2 Gateway Options:
         options : network_name      optional string
         options : l2gateway-chassis
                                     optional string
         tag                         optional integer, in range 1 to 4,095
       VTEP Options:
         options : vtep-physical-switch
                                     optional string
         options : vtep-logical-switch
                                     optional string
       VMI (or VIF) Options:
         options : requested-chassis
                                     optional string
         options : qos_max_rate      optional string
         options : qos_burst         optional string
         options : qdisc_queue_id    optional string, containing  an  integer,
                                     in range 1 to 61,440
       Chassis Redirect Options:
         options : distributed-port  optional string
         options : redirect-chassis  optional string
       Nested Containers:
         parent_port                 optional string
         tag                         optional integer, in range 1 to 4,095
       Virtual ports:
         virtual_parent              optional string
       Naming:
         external_ids : name         optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
     Core Features:

       datapath: Datapath_Binding
              The logical datapath to which the logical port belongs.

       logical_port: string (must be unique within table)
              A logical port, taken from name in the OVN_Northbound database’s
              Logical_Switch_Port table. OVN does not prescribe  a  particular
              format for the logical port ID.

       encap: optional weak reference to Encap
              Points  to  supported  encapsulation  configurations to transmit
              logical dataplane packets to this chassis. Each entry is a Encap
              record that describes the configuration.

       chassis: optional weak reference to Chassis
              The meaning of this column depends on the value of the type col‐
              umn. This is the meaning for each type

              (empty string)
                     The physical location of the logical  port.  To  success‐
                     fully  identify  a chassis, this column must be a Chassis
                     record. This is populated by ovn-controller.

              vtep   The physical location of the  hardware_vtep  gateway.  To
                     successfully  identify  a  chassis, this column must be a
                     Chassis record. This is populated by ovn-controller-vtep.

              localnet
                     Always empty. A localnet port is realized on every  chas‐
                     sis  that  has connectivity to the corresponding physical
                     network.

              localport
                     Always empty. A localport port is present on every  chas‐
                     sis.

              l3gateway
                     The  physical location of the L3 gateway. To successfully
                     identify a chassis, this column must be a Chassis record.
                     This is populated by ovn-controller based on the value of
                     the options:l3gateway-chassis column in this table.

              l2gateway
                     The physical location of this L2 gateway. To successfully
                     identify a chassis, this column must be a Chassis record.
                     This is populated by ovn-controller based on the value of
                     the options:l2gateway-chassis column in this table.

       gateway_chassis: set of Gateway_Chassiss
              A list of Gateway_Chassis.

              This  should  only be populated for ports with type set to chas
              sisredirect. This column defines the list  of  chassis  used  as
              gateways where traffic will be redirected through.

       ha_chassis_group: optional HA_Chassis_Group
              This  should  only be populated for ports with type set to chas
              sisredirect. This column defines the HA  chassis  group  with  a
              list  of HA chassis used as gateways where traffic will be redi‐
              rected through.

       tunnel_key: integer, in range 1 to 32,767
              A number that represents the logical port in the key  (e.g.  STT
              key or Geneve TLV) field carried within tunnel protocol packets.

              The tunnel ID must be unique within the scope of a logical data‐
              path.

       mac: set of strings
              The Ethernet address or addresses used as a  source  address  on
              the logical port, each in the form xx:xx:xx:xx:xx:xx. The string
              unknown is also allowed to indicate that the logical port has an
              unknown set of (additional) source addresses.

              A  VM interface would ordinarily have a single Ethernet address.
              A gateway port might initially only have unknown, and  then  add
              MAC addresses to the set as it learns new source addresses.

       type: string
              A type for this logical port. Logical ports can be used to model
              other types of connectivity into an OVN logical switch. The fol‐
              lowing types are defined:

              (empty string)
                     VM (or VIF) interface.

              patch  One  of  a pair of logical ports that act as if connected
                     by a patch cable. Useful for connecting two logical data‐
                     paths,  e.g.  to  connect  a  logical router to a logical
                     switch or to another logical router.

              l3gateway
                     One of a pair of logical ports that act as  if  connected
                     by a patch cable across multiple chassis. Useful for con‐
                     necting a logical switch with a Gateway router (which  is
                     only resident on a particular chassis).

              localnet
                     A  connection  to  a locally accessible network from each
                     ovn-controller instance. A logical switch can only have a
                     single  localnet  port  attached.  This  is used to model
                     direct connectivity to an existing network.

              localport
                     A connection to a local VIF. Traffic that  arrives  on  a
                     localport  is  never  forwarded  over a tunnel to another
                     chassis. These ports are present  on  every  chassis  and
                     have  the  same  address  in all of them. This is used to
                     model connectivity to local services that  run  on  every
                     hypervisor.

              l2gateway
                     An  L2 connection to a physical network. The chassis this
                     Port_Binding is bound to will serve as an L2  gateway  to
                     the network named by options:network_name.

              vtep   A  port to a logical switch on a VTEP gateway chassis. In
                     order to get this port correctly recognized  by  the  OVN
                     controller,    the    options:vtep-physical-switch    and
                     options:vtep-logical-switch must also be defined.

              chassisredirect
                     A logical port that  represents  a  particular  instance,
                     bound  to a specific chassis, of an otherwise distributed
                     parent port (e.g. of type patch). A chassisredirect  port
                     should  never be used as an inport. When an ingress pipe‐
                     line sets the outport, it may set the value to a  logical
                     port  of type chassisredirect. This will cause the packet
                     to be directed to a specific chassis  to  carry  out  the
                     egress pipeline. At the beginning of the egress pipeline,
                     the outport will be reset to the value of the distributed
                     port.

              virtual
                     Represents  a  logical port with an virtual ip. This vir
                     tual ip can be configured on a  logical  port  (which  is
                     refered as virtual parent).

     Patch Options:

       These options apply to logical ports with type of patch.

       options : peer: optional string
              The  logical_port  in the Port_Binding record for the other side
              of the patch. The named logical_port  must  specify  this  logi
              cal_port  in its own peer option. That is, the two patch logical
              ports must have reversed logical_port and peer values.

       nat_addresses: set of strings
              MAC address followed by a list of  SNAT  and  DNAT  external  IP
              addresses, followed by is_chassis_resident("lport"), where lport
              is the name of a logical port on the same chassis where the cor‐
              responding  NAT  rules  are applied. This is used to send gratu‐
              itous ARPs for SNAT and DNAT external IP addresses via localnet,
              from the chassis where lport resides. Example: 80:fa:5b:06:72:b7
              158.36.44.22  158.36.44.24   is_chassis_resident("foo1").   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 from the chassis where the logical port "foo1"
              resides.

     L3 Gateway Options:

       These options apply to logical ports with type of l3gateway.

       options : peer: optional string
              The logical_port in the Port_Binding record for the  other  side
              of  the  ’l3gateway’  port.  The named logical_port must specify
              this logical_port in its own  peer  option.  That  is,  the  two
              ’l3gateway’  logical  ports  must have reversed logical_port and
              peer values.

       options : l3gateway-chassis: optional string
              The chassis in which the port resides.

       options : nat-addresses: optional string
              MAC address of the l3gateway port followed by a list of SNAT and
              DNAT external IP addresses. This is used to send gratuitous ARPs
              for SNAT and DNAT external IP addresses via  localnet.  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
              is used in OVS versions prior to 2.8.

       nat_addresses: set of strings
              MAC address of the l3gateway port followed by a list of SNAT and
              DNAT external IP addresses. This is used to send gratuitous ARPs
              for SNAT and DNAT external IP addresses via  localnet.  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
              is used in OVS version 2.8 and later versions.

     Localnet Options:

       These options apply to logical ports with type of localnet.

       options : network_name: optional string
              Required.   ovn-controller   uses   the   configuration    entry
              ovn-bridge-mappings to determine how to connect to this network.
              ovn-bridge-mappings is a list of network names mapped to a local
              OVS  bridge  that provides access to that network. An example of
              configuring ovn-bridge-mappings would be: .IP
              $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1

              When a logical switch has a localnet port attached, every  chas‐
              sis  that  may  have a local vif attached to that logical switch
              must have a bridge mapping configured to  reach  that  localnet.
              Traffic  that arrives on a localnet port is never forwarded over
              a tunnel to another chassis.

       tag: optional integer, in range 1 to 4,095
              If set, indicates 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.

     L2 Gateway Options:

       These options apply to logical ports with type of l2gateway.

       options : network_name: optional string
              Required.    ovn-controller   uses   the   configuration   entry
              ovn-bridge-mappings to determine how to connect to this network.
              ovn-bridge-mappings is a list of network names mapped to a local
              OVS bridge that provides access to that network. An  example  of
              configuring ovn-bridge-mappings would be: .IP
              $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1

              When a logical switch has a l2gateway port attached, the chassis
              that the l2gateway port is bound to must have a  bridge  mapping
              configured to reach the network identified by network_name.

       options : l2gateway-chassis: optional string
              Required. The chassis in which the port resides.

       tag: optional integer, in range 1 to 4,095
              If  set,  indicates  that the gateway is connected to a specific
              VLAN on the physical network. The  VLAN  ID  is  used  to  match
              incoming traffic and is also added to outgoing traffic.

     VTEP Options:

       These options apply to logical ports with type of 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.
              Must be set when type is vtep.

     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  dur‐
              ing  a live migration. It can also prevent similar thrashing due
              to a mis-configuration, if a port  is  accidentally  created  on
              more than one chassis.

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

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

       options : qdisc_queue_id: optional string, containing  an  integer,  in
       range 1 to 61,440
              Indicates  the queue number on the physical device. This is same
              as the queue_id used in OpenFlow in struct ofp_action_enqueue.

     Chassis Redirect Options:

       These options apply to logical ports with type of chassisredirect.

       options : distributed-port: optional string
              The name of the distributed port for which this  chassisredirect
              port represents a particular instance.

       options : redirect-chassis: optional string
              The  chassis that this chassisredirect port is bound to. This is
              taken from options:redirect-chassis in the OVN_Northbound  data‐
              base’s Logical_Router_Port table.

     Nested Containers:

       These columns support containers nested within a VM. Specifically, they
       are used when type is empty and logical_port identifies  the  interface
       of  a  container  spawned inside a VM. They are empty for containers or
       VMs that run directly on a hypervisor.

       parent_port: optional string
              This is taken from parent_name in the OVN_Northbound  database’s
              Logical_Switch_Port table.

       tag: optional integer, in range 1 to 4,095
              Identifies  the  VLAN tag in the network traffic associated with
              that container’s network interface.

              This column is used for a different purpose when type is  local
              net  (see  Localnet Options, above) or l2gateway (see L2 Gateway
              Options, above).

     Virtual ports:

       virtual_parent: optional string
              This column is set by ovn-controller with one of the value  from
              the  options:virtual-parents  in  the  OVN_Northbound database’s
              Logical_Switch_Port table when the OVN action bind_vport is exe‐
              cuted.  ovn-controller also sets the chassis column when it exe‐
              cutes this action with its chassis id.

              ovn-controller sets this column only if the type is "virtual".

     Naming:

       external_ids : name: optional string
              For a logical switch port, ovn-northd copies  this  from  exter
              nal_ids:neutron:port_name  in  the  Logical_Switch_Port table in
              the OVN_Northbound database, if it is a nonempty string.

              For a logical switch port, ovn-northd  does  not  currently  set
              this key.

     Common Columns:

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

              The  ovn-northd  program  populates this column with all entries
              into the external_ids column of the Logical_Switch_Port table of
              the OVN_Northbound database.

MAC_Binding TABLE
       Each  row  in  this  table specifies a binding from an IP address to an
       Ethernet address that has been discovered through  ARP  (for  IPv4)  or
       neighbor discovery (for IPv6). This table is primarily used to discover
       bindings on physical networks, because IP-to-MAC bindings  for  virtual
       machines are usually populated statically into the Port_Binding table.

       This  table  expresses  a  functional  relationship:  MAC_Binding(logi
       cal_port, ip) = mac.

       In outline, the lifetime of a logical router’s MAC binding  looks  like
       this:

              1.  On  hypervisor  1, a logical router determines that a packet
                  should be forwarded to IP address A on  one  of  its  router
                  ports.  It  uses  its logical flow table to determine that A
                  lacks a static IP-to-MAC binding and the get_arp  action  to
                  determine that it lacks a dynamic IP-to-MAC binding.

              2.  Using  an  OVN logical arp action, the logical router gener‐
                  ates and sends a broadcast ARP request to the  router  port.
                  It drops the IP packet.

              3.  The  logical switch attached to the router port delivers the
                  ARP request to all of its ports. (It  might  make  sense  to
                  deliver it only to ports that have no static IP-to-MAC bind‐
                  ings, but this could also be surprising behavior.)

              4.  A host or VM on hypervisor 2 (which might  be  the  same  as
                  hypervisor  1)  attached  to  the logical switch owns the IP
                  address in question. It composes an ARP reply  and  unicasts
                  it to the logical router port’s Ethernet address.

              5.  The  logical  switch  delivers  the ARP reply to the logical
                  router port.

              6.  The logical router flow table executes a put_arp action.  To
                  record  the  IP-to-MAC binding, ovn-controller adds a row to
                  the MAC_Binding table.

              7.  On  hypervisor  1,  ovn-controller  receives   the   updated
                  MAC_Binding table from the OVN southbound database. The next
                  packet destined to A through  the  logical  router  is  sent
                  directly to the bound Ethernet address.

   Summary:
       logical_port                  string
       ip                            string
       mac                           string
       datapath                      Datapath_Binding

   Details:
       logical_port: string
              The logical port on which the binding was discovered.

       ip: string
              The bound IP address.

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

       datapath: Datapath_Binding
              The logical datapath to which the logical port belongs.

DHCP_Options TABLE
       Each  row in this table stores the DHCP Options supported by native OVN
       DHCP. ovn-northd populates this table with the supported DHCP  options.
       ovn-controller  looks  up  this table to get the DHCP codes of the DHCP
       options defined in the "put_dhcp_opts" action. Please refer to the  RFC
       2132  "https://tools.ietf.org/html/rfc2132"  for  the  possible list of
       DHCP options that can be defined here.

   Summary:
       name                          string
       code                          integer, in range 0 to 254
       type                          string, one of bool, ipv4, static_routes,
                                     str, uint16, uint32, or uint8

   Details:
       name: string
              Name of the DHCP option.

              Example. name="router"

       code: integer, in range 0 to 254
              DHCP option code for the DHCP option as defined in the RFC 2132.

              Example. code=3

       type: string, one of bool, ipv4, static_routes, str, uint16, uint32, or
       uint8
              Data type of the DHCP option code.

              value: bool
                     This indicates that the value of the  DHCP  option  is  a
                     bool.

                     Example.       "name=ip_forward_enable",       "code=19",
                     "type=bool".

                     put_dhcp_opts(..., ip_forward_enable = 1,...)

              value: uint8
                     This indicates that the value of the DHCP  option  is  an
                     unsigned int8 (8 bits)

                     Example. "name=default_ttl", "code=23", "type=uint8".

                     put_dhcp_opts(..., default_ttl = 50,...)

              value: uint16
                     This  indicates  that  the value of the DHCP option is an
                     unsigned int16 (16 bits).

                     Example. "name=mtu", "code=26", "type=uint16".

                     put_dhcp_opts(..., mtu = 1450,...)

              value: uint32
                     This indicates that the value of the DHCP  option  is  an
                     unsigned int32 (32 bits).

                     Example. "name=lease_time", "code=51", "type=uint32".

                     put_dhcp_opts(..., lease_time = 86400,...)

              value: ipv4
                     This  indicates  that  the value of the DHCP option is an
                     IPv4 address or addresses.

                     Example. "name=router", "code=3", "type=ipv4".

                     put_dhcp_opts(..., router = 10.0.0.1,...)

                     Example. "name=dns_server", "code=6", "type=ipv4".

                     put_dhcp_opts(..., dns_server = {8.8.8.8 7.7.7.7},...)

              value: static_routes
                     This indicates that the value of the DHCP option contains
                     a pair of IPv4 route and next hop addresses.

                     Example.    "name=classless_static_route",    "code=121",
                     "type=static_routes".

                     put_dhcp_opts(...,        classless_static_route        =
                     {30.0.0.0/24,10.0.0.4,0.0.0.0/0,10.0.0.1}...)

              value: str
                     This  indicates  that  the  value of the DHCP option is a
                     string.

                     Example. "name=host_name", "code=12", "type=str".

DHCPv6_Options TABLE
       Each row in this table stores the DHCPv6 Options  supported  by  native
       OVN  DHCPv6.  ovn-northd populates this table with the supported DHCPv6
       options. ovn-controller looks up this table to get the DHCPv6 codes  of
       the  DHCPv6 options defined in the put_dhcpv6_opts action. Please refer
       to RFC 3315 and RFC 3646 for the list of DHCPv6  options  that  can  be
       defined here.

   Summary:
       name                          string
       code                          integer, in range 0 to 254
       type                          string, one of ipv6, mac, or str

   Details:
       name: string
              Name of the DHCPv6 option.

              Example. name="ia_addr"

       code: integer, in range 0 to 254
              DHCPv6  option  code  for  the  DHCPv6  option as defined in the
              appropriate RFC.

              Example. code=3

       type: string, one of ipv6, mac, or str
              Data type of the DHCPv6 option code.

              value: ipv6
                     This indicates that the value of the DHCPv6 option is  an
                     IPv6 address(es).

                     Example. "name=ia_addr", "code=5", "type=ipv6".

                     put_dhcpv6_opts(..., ia_addr = ae70::4,...)

              value: str
                     This  indicates  that the value of the DHCPv6 option is a
                     string.

                     Example. "name=domain_search", "code=24", "type=str".

                     put_dhcpv6_opts(..., domain_search = ovn.domain,...)

              value: mac
                     This indicates that the value of the DHCPv6 option  is  a
                     MAC address.

                     Example. "name=server_id", "code=2", "type=mac".

                     put_dhcpv6_opts(..., server_id = 01:02:03:04L05:06,...)

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 con‐
       nections to remote clients. It can also  listen  for  database  connec‐
       tions.

   Summary:
       Core Features:
         target                      string (must be unique within table)
         read_only                   boolean
         role                        string
       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  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  speci‐
                     fied 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  given  host,  which  can
                     either  be  a DNS name (if built with unbound library) or
                     an IP address (IPv4 or IPv6). 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 IP address  (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. Spec‐
                     ify 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.

       read_only: boolean
              true to restrict these connections  to  read-only  transactions,
              false to allow them to modify the database.

       role: string
              String containing role name for this connection entry.

     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 recon‐
              nect. 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 con‐
       nections  (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  omit‐
       ted.

       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  dis‐
              connected.

       status : locks_held: optional string
              Space-separated  list  of the names of OVSDB locks that the con‐
              nection 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 con‐
              nection is currently waiting to acquire. Omitted if the  connec‐
              tion is not waiting for any locks.

       status : locks_lost: optional string
              Space-separated  list  of the names of OVSDB locks that the con‐
              nection 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 con‐
              nection 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

SSL TABLE
       SSL configuration for ovn-sb 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  cer‐
              tificate 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 bootstrap‐
              ping.

       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 sup‐
              ported 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

DNS TABLE
       Each row  in  this  table  stores  the  DNS  records.  The  OVN  action
       dns_lookup uses this table for DNS resolution.

   Summary:
       records                       map of string-string pairs
       datapaths                     set of 1 or more Datapath_Bindings
       Common Columns:
         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
              a string of IP address(es) separated by comma or  space  as  the
              value.

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

       datapaths: set of 1 or more Datapath_Bindings
              The  DNS  records  defined in the column records will be applied
              only to the DNS queries originating from the  datapaths  defined
              in this column.

     Common Columns:

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

RBAC_Role TABLE
       Role table for role-based access controls.

   Summary:
       name                          string
       permissions                   map of string-weak reference to RBAC_Per
                                     mission pairs

   Details:
       name: string
              The role name, corresponding to the role column in  the  Connec
              tion table.

       permissions: map of string-weak reference to RBAC_Permission pairs
              A mapping of table names to rows in the RBAC_Permission table.

RBAC_Permission TABLE
       Permissions table for role-based access controls.

   Summary:
       table                         string
       authorization                 set of strings
       insert_delete                 boolean
       update                        set of strings

   Details:
       table: string
              Name of table to which this row applies.

       authorization: set of strings
              Set  of  strings  identifying columns and column:key pairs to be
              compared with client ID. At least one match is required in order
              to  be  authorized. A zero-length string is treated as a special
              value indicating all clients should be considered authorized.

       insert_delete: boolean
              When "true", row insertions and  authorized  row  deletions  are
              permitted.

       update: set of strings
              Set  of  strings  identifying  columns and column:key pairs that
              authorized clients are allowed to modify.

Gateway_Chassis TABLE
       Association of Port_Binding rows of type chassisredirect to a  Chassis.
       The  traffic  going out through a specific chassisredirect port will be
       redirected to a chassis, or a set of them in high availability configu‐
       rations.

   Summary:
       name                          string (must be unique within table)
       chassis                       optional weak reference to Chassis
       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: optional weak reference to Chassis
              The Chassis to which we send the traffic.

       priority: integer, in range 0 to 32,767
              This is the  priority  the  specific  Chassis  among  all  Gate‐
              way_Chassis belonging to the same Port_Binding.

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

     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

HA_Chassis TABLE
   Summary:
       chassis                       optional weak reference to Chassis
       priority                      integer, in range 0 to 32,767
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       chassis: optional weak reference to Chassis
              The Chassis which provides the HA functionality.

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

     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 availabil‐
       ity 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 provid‐
       ing the HA. If ha_chassis_group column of the table Port_Binding refer‐
       ences this table, then this HA chassis group provides the gateway func‐
       tionality and redirects the gateway  traffic  to  the  master  of  this
       group.

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

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

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

       ref_chassis: set of weak reference to Chassiss
              A list of chassis which references this HA chassis group.

     Common Columns:

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

Controller_Event TABLE
       Database  table  used  by  ovn-controller to report CMS related events.
       Please note there is no guarantee a given event is written exactly once
       in  the  db.  It is CMS responsibility to squash duplicated lines or to
       filter out duplicated events

   Summary:
       event_type                    string, must be empty_lb_backends
       event_info                    map of string-string pairs
       chassis                       optional weak reference to Chassis
       seq_num                       integer

   Details:
       event_type: string, must be empty_lb_backends
              Event type occurred

       event_info: map of string-string pairs
              Key-value pairs used to specify event info to the CMS.  Possible
              values are:

              ·      vip: VIP reported for the empty_lb_backends event

              ·      protocol:    Transport    protocol   reported   for   the
                     empty_lb_backends event

              ·      load_balancer: UUID of the load balancer reported for the
                     empty_lb_backends event

       chassis: optional weak reference to Chassis
              This column is a Chassis record to identify the chassis that has
              managed a given event.

       seq_num: integer
              Event sequence number. Global counter for  controller  generated
              events. It can be used by the CMS to detect possible duplication
              of the same event.

IP_Multicast TABLE
       IP Multicast configuration options. For now only applicable to IGMP.

   Summary:
       datapath                      weak reference to Datapath_Binding  (must
                                     be unique within table)
       enabled                       optional boolean
       querier                       optional boolean
       table_size                    optional integer
       idle_timeout                  optional integer
       query_interval                optional integer
       seq_no                        integer
       Querier configuration options:
         eth_src                     string
         ip4_src                     string
         ip6_src                     string
         query_max_resp              optional integer

   Details:
       datapath: weak reference to Datapath_Binding (must be unique within ta‐
       ble)
              Datapath_Binding entry for which these configuration options are
              defined.

       enabled: optional boolean
              Enables/disables multicast snooping. Default: disabled.

       querier: optional boolean
              Enables/disables  multicast  querying. If enabled then multicast
              querying is enabled by default.

       table_size: optional integer
              Limits the number of  multicast  groups  that  can  be  learned.
              Default: 2048 groups per datapath.

       idle_timeout: optional integer
              Configures the idle timeout (in seconds) for IP multicast groups
              if multicast snooping is enabled. Default: 300 seconds.

       query_interval: optional integer
              Configures the  interval  (in  seconds)  for  sending  multicast
              queries if snooping and querier are enabled. Default: idle_time
              out/2 seconds.

       seq_no: integer
              ovn-controller reads this value and flushes all  learned  multi‐
              cast groups when it detects that seq_no was changed.

     Querier configuration options:

       The  ovn-controller  process that runs on OVN hypervisor nodes uses the
       following columns to determine field values in IGMP/MLD queries that it
       originates:

       eth_src: string
              Source Ethernet address.

       ip4_src: string
              Source IPv4 address.

       ip6_src: string
              Source IPv6 address.

       query_max_resp: optional integer
              Value  (in seconds) to be used as "max-response" field in multi‐
              cast queries. Default: 1 second.
IGMP_Group TABLE
       Contains learned IGMP groups indexed by address/datapath/chassis.

   Summary:
       address                       string
       datapath                      optional weak reference to Datapath_Bind
                                     ing
       chassis                       optional weak reference to Chassis
       ports                         set of weak reference to Port_Bindings

   Details:
       address: string
              Destination IPv4 address for the IGMP group.

       datapath: optional weak reference to Datapath_Binding
              Datapath to which this IGMP group belongs.

       chassis: optional weak reference to Chassis
              Chassis to which this IGMP group belongs.

       ports: set of weak reference to Port_Bindings
              The destination port bindings for this IGMP group.

Service_Monitor TABLE
       This table montiors a service for its liveliness. The service can be an
       IPv4 tcp or a udp service. ovn-controller periodically sends  out  ser‐
       vice  monitor  packets  and  updates the status of the service. Service
       monitoring for IPv6 services is not supported.

   Summary:
       ip                            string
       protocol                      optional string, either tcp or udp
       port                          integer, in range 0 to 32,767
       logical_port                  string
       status                        optional string, one of  error,  offline,
                                     or online
       src_mac                       string
       src_ip                        string
       Service monitor 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:
       ip: string
              IP of the service to be monitored. Only IPv4 is supported.

       protocol: optional string, either tcp or udp
              The protocol of the service. It can be either tcp or udp.

       port: integer, in range 0 to 32,767
              The tcp or udp port of the service.

       logical_port: string
              The  VIF  of  logical  port on which the service is running. The
              ovn-controller which binds this logical_port monitors  the  ser‐
              vice by sending periodic monitor packets.

       status: optional string, one of error, offline, or online
              The ovn-controller which binds the logical_port updates the sta‐
              tus to online offline or error.

              For tcp service, ovn-controller sends a TCP SYN  packet  to  the
              service  and  expects a TCP ACK response to consider the service
              to be online.

              For udp service, ovn-controller sends a udp packet to  the  ser‐
              vice  and  doesn’t  expect any reply. If it receives ICMP reply,
              then it considers the service to be offline.

       src_mac: string
              Source Ethernet address to use in the service monitor packet.

       src_ip: string
              Source IPv4 address to use in the service monitor packet.

     Service monitor options:

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

       options : timeout: optional string, containing an integer
              The time, in seconds, after  which  the  service  monitor  check
              times out.

       options : success_count: optional string, containing an integer
              The  number of successful checks after which the service is con‐
              sidered online.

       options : failure_count: optional string, containing an integer
              The number of failure checks after which the service is  consid‐
              ered offline.

     Common Columns:

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



Open vSwitch 20.03.90           DB Schema 2.7.0                      ovn-sb(5)