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-architecture(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 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 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 participates.

The logical network data is ultimately controlled by the cloud management 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 configuration, 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.

These tables link logical and physical components. They show the current placement of logical components (such as VMs and VIFs) onto chassis, and map logical entities to the values that represent them in tunnel 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 location, so the consistency needs are minimal.

The Port_Binding and Datapath_Binding tables contain binding data.

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 networks.

  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-controller/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 comprehensive.

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.

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:

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.

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

options: map of string-string pairs

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

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.

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

ssl: optional SSL
    Global SSL configuration.

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-controller-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
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-controller-vtep populates this column with name in the hardware_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 mappings 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 configured 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 configured 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 configured in the external_ids:ovn-cms-options column of the Open_vSwitch database’s Open_vSwitch table. See ovn-controller(8) for more information.

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

external_ids: map of string-string pairs

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.

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 dedicated nodes that do not host VMs and will be controlled by ovn-controller-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-physical-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 chassis. 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
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. Currently, the only option that has been defined is csum.

    csum indicates that encapsulation checksums can be transmitted and received with reasonable performance. It is a hint 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, this actually significantly increases throughput in most common cases when running on Linux based hosts without NICs supporting encapsulation hardware offload (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 validated 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 presence 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.

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 populates 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 centralized 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 implementation. 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 pipeline, which may either drop the packet or deliver it to the destination. Between the two pipelines, outputs to logical multicast groups are expanded into logical ports, so that the egress pipeline only processes a single logical output port at a time. Between the two pipelines 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 logical 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 registers aren’t preserve across tunnel encapsulation).

To execute the egress pipeline, OVN again searches the Logical_Flow table 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 multiple, 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 Logical 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 table 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 expressions in a programming language.

    The most important components of match expression are comparisons 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 Measurement, 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 nominal; other predicates have Boolean level of measurement.

    Level of Measurement. See http://en.wikipedia.org/wiki/Level_of_measurement for the statistical 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 ordinal 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 (==, !=, <, <=, >, and >=) 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 examples: all of these are just identifiers assigned arbitrarily with no deeper meaning. In OpenFlow and Open vSwitch, bits in these fields generally aren’t individually addressable.

        OVN only supports arithmetic tests for equality on nominal 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 priority.)

        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 measurement.

        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 example, 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 ==, !=, <, <=, >, and >= 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 prefixed 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 implementation 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 parentheses 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.

    •   ()

    •   == != < <= > >=

    •   !

    •   && ||

    Comments may be introduced by //, which extends to the next new-line. Comments within a line may be bracketed by /* and */. Multiline 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. outport 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.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 contain 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 multicast group, the egress pipeline runs once for each logical port in the group.

        In the egress pipeline, this action performs the actual output to the outport logical port. (In the egress pipeline, 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 constant, 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 sigificant 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 partially 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.

    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, specify 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 <-> 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 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. 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 supplied, 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 connection 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 followed 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 provided 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);

    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 initialized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will probably 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, 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

    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 = 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 configures 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 destination 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 automatically 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 automatically 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 solicitation 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);

    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 currently 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.

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

        The ICMPv4 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. 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)

        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 initialized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will probably 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

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.

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. Multicast groups allow a single packet transmitted over a tunnel to a hypervisor 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 tunnel_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 column specified kbps or pktps.

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

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 implements 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 tunnel_key. The rest of the data in this table does not affect packet forwarding.

  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
    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 encapsulation.

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

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.

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 example 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 hypervisor/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 IntegrationGuide.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)
    chassis
        optional weak reference to Chassis
    gateway_chassis
        set of Gateway_Chassiss
    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
Naming:
    external_ids : name
        optional string
Common Columns:
    external_ids
        map of string-string pairs

  Details:

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.

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

    (empty string)
        The physical location of the logical port. To successfully 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 chassis that has connectivity to the corresponding physical network.

    localport
        Always empty. A localport port is present on every chassis.

    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 chassisredirect. This column defines the list of chassis used as gateways where traffic will be redirected 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 datapath.

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 following 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 datapaths, 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 connecting 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 pipeline 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.

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 logical_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 corresponding NAT rules are applied. This is used to send gratuitous 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.

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.

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 chassis 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.

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.

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.

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

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

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

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

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.

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 database’s Logical_Router_Port table.

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 localnet (see Localnet Options, above) or l2gateway (see L2 Gateway Options, above).

external_ids : name: optional string
    For a logical switch port, ovn-northd copies this from external_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.

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(logical_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 generates 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 bindings, 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 connections to remote clients. It can also listen for database connections.

  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:

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 specified via command-line options or the SSL table.

        If port is not specified, it defaults to 6640.

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

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

        If port is not specified, it defaults to 6640.

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

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.

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

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

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

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

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

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

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

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

    VOID
        Connection is disabled.

    BACKOFF
        Attempting to reconnect at an increasing period.

    CONNECTING
        Attempting to connect.

    ACTIVE
        Connected, remote host responsive.

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

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

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

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

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

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

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

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

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

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 certificate authority (CA) used by the controller and manager, that certifies the switch’s private key, identifying a trustworthy switch.

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

bootstrap_ca_cert: boolean
    If set to true, then Open vSwitch will attempt to obtain the CA certificate from the controller on its first SSL connection and save it to the named PEM file. If it is successful, it will immediately drop the connection and reconnect, and from then on all SSL connections must be authenticated by a certificate signed by the CA certificate thus obtained. This option exposes the SSL connection to a man-in-the-middle attack obtaining the initial CA certificate. It may still be useful for bootstrapping.

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

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

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.

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_Permission pairs

  Details:

name: string
    The role name, corresponding to the role column in the Connection 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 configurations.

  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 Gateway_Chassis belonging to the same Port_Binding.

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

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

external_ids: map of string-string pairs