ovn-sb(5) Open vSwitch Manual ovn-sb(5) NAME ovn-sb - OVN_Southbound database schema This database holds logical and physical configuration and state for the Open Virtual Network (OVN) system to support virtual network ab‐ straction. 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 Physical network tables contain information about the chassis nodes in the system. This contains all the information necessary to wire the overlay, such as IP addresses, supported tunnel types, and security keys. The amount of physical network data is small (O(n) in the number of chassis) and it changes infrequently, so it can be replicated to every chassis. The Chassis and Encap tables are the physical network tables. Logical Network Logical network tables contain the topology of logical switches and routers, ACLs, firewall rules, and everything needed to describe how packets traverse a logical network, represented as logical datapath flows (see Logical Datapath Flows, below). Logical network data may be large (O(n) in the number of logical ports, ACL rules, etc.). Thus, to improve scaling, each chassis should receive only data related to logical networks in which that chassis partici‐ pates. The logical network data is ultimately controlled by the cloud manage‐ ment system (CMS) running northbound of OVN. That CMS determines the entire OVN logical configuration and therefore the logical network data at any given time is a deterministic function of the CMS’s configura‐ tion, although that happens indirectly via the OVN_Northbound database and ovn-northd. Logical network data is likely to change more quickly than physical network data. This is especially true in a container environment where containers are created and destroyed (and therefore added to and deleted from logical switches) quickly. The Logical_Flow, Multicast_Group, Address_Group, DHCP_Options, DHCPv6_Options, and DNS tables contain logical network data. Logical-physical bindings These tables link logical and physical components. They show the cur‐ rent placement of logical components (such as VMs and VIFs) onto chas‐ sis, and map logical entities to the values that represent them in tun‐ nel encapsulations. These tables change frequently, at least every time a VM powers up or down or migrates, and especially quickly in a container environment. The amount of data per VM (or VIF) is small. Each chassis is authoritative about the VMs and VIFs that it hosts at any given time and can efficiently flood that state to a central loca‐ tion, so the consistency needs are minimal. The Port_Binding and Datapath_Binding tables contain binding data. MAC bindings The MAC_Binding table tracks the bindings from IP addresses to Ethernet addresses that are dynamically discovered using ARP (for IPv4) and neighbor discovery (for IPv6). Usually, IP-to-MAC bindings for virtual machines are statically populated into the Port_Binding table, so MAC_Binding is primarily used to discover bindings on physical net‐ works. Common Columns Some tables contain a special column named external_ids. This column has the same form and purpose each place that it appears, so we de‐ scribe it here to save space later. external_ids: map of string-string pairs Key-value pairs for use by the software that manages the OVN Southbound database rather than by ovn-con‐ troller/ovn-controller-vtep. In particular, ovn-northd can use key-value pairs in this column to relate entities in the southbound database to higher-level entities (such as entities in the OVN Northbound database). Individual key-value pairs in this column may be documented in some cases to aid in understanding and troubleshooting, but the reader should not mistake such documentation as com‐ prehensive. TABLE SUMMARY The following list summarizes the purpose of each of the tables in the OVN_Southbound database. Each table is described in more detail on a later page. Table Purpose SB_Global Southbound configuration Chassis Physical Network Hypervisor and Gateway Information Chassis_Private Chassis Private Encap Encapsulation Types Address_Set Address Sets Port_Group Port Groups Logical_Flow Logical Network Flows Logical_DP_Group Logical Datapath Groups Multicast_Group Logical Port Multicast Groups Meter Meter entry Meter_Band Band for meter entries Datapath_Binding Physical-Logical Datapath Bindings Port_Binding Physical-Logical Port Bindings MAC_Binding IP to MAC bindings DHCP_Options DHCP Options supported by native OVN DHCP DHCPv6_Options DHCPv6 Options supported by native OVN DHCPv6 Connection OVSDB client connections. SSL SSL configuration. DNS Native DNS resolution RBAC_Role RBAC_Role configuration. RBAC_Permission RBAC_Permission configuration. Gateway_Chassis Gateway_Chassis configuration. HA_Chassis HA_Chassis configuration. HA_Chassis_Group HA_Chassis_Group configuration. Controller_Event Controller Event table IP_Multicast IP_Multicast configuration. IGMP_Group IGMP_Group configuration. Service_Monitor Service_Monitor configuration. Load_Balancer Load_Balancer configuration. BFD BFD configuration. FDB Port to MAC bindings SB_Global TABLE Southbound configuration for an OVN system. This table must have ex‐ actly 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 Options for configuring Load Balancers: options : lb_hairpin_use_ct_mark optional string Connection Options: connections set of Connections ssl optional SSL Security Configurations: ipsec boolean Details: Status: This column allow a client to track the overall configuration state of the system. nb_cfg: integer Sequence number for the configuration. When a CMS or ovn-nbctl updates the northbound database, it increments the nb_cfg column in the NB_Global table in the northbound database. In turn, when ovn-northd updates the southbound database to bring it up to date with these changes, it updates this column to the same value. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. options: map of string-string pairs Common options: options: map of string-string pairs This column provides general key/value settings. The supported options are described individually below. Options for configuring BFD: These options apply when ovn-controller configures BFD on tunnels in‐ terfaces. 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 in‐ terfaces. Options for configuring Load Balancers: These options apply when ovn-controller configures load balancer re‐ lated flows. options : lb_hairpin_use_ct_mark: optional string This value is automatically set to true by ovn-northd when ac‐ tion ct_lb_mark is used for new load balancer sessions. ovn-con‐ troller then knows that it should check ct_mark.natted to detect load balanced traffic. Connection Options: connections: set of Connections Database clients to which the Open vSwitch database server should connect or on which it should listen, along with options for how these connections should be configured. See the Connec‐ tion table for more information. ssl: optional SSL Global SSL configuration. Security Configurations: ipsec: boolean Tunnel encryption configuration. If this column is set to be true, all OVN tunnels will be encrypted with IPsec. Chassis TABLE Each row in this table represents a hypervisor or gateway (a chassis) in the physical network. Each chassis, via ovn-controller/ovn-con‐ troller-vtep, adds and updates its own row, and keeps a copy of the re‐ maining 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 other_config : ovn-bridge-mappings optional string other_config : datapath-type optional string other_config : iface-types optional string other_config : ovn-cms-options optional string other_config : is-interconn optional string other_config : is-remote optional string transport_zones set of strings other_config : ovn-chassis-mac-mappings optional string other_config : port-up-notif optional string Common Columns: external_ids map of string-string pairs Encapsulation Configuration: encaps set of 1 or more Encaps Gateway Configuration: vtep_logical_switches set of strings Details: name: string (must be unique within table) OVN does not prescribe a particular format for chassis names. ovn-controller populates this column using external_ids:system- id in the Open_vSwitch database’s Open_vSwitch table. ovn-con‐ troller-vtep populates this column with name in the hard‐ ware_vtep database’s Physical_Switch table. hostname: string The hostname of the chassis, if applicable. ovn-controller will populate this column with the hostname of the host it is running on. ovn-controller-vtep will leave this column empty. nb_cfg: integer Deprecated. This column is replaced by the nb_cfg column of the Chassis_Private table. other_config : ovn-bridge-mappings: optional string ovn-controller populates this key with the set of bridge map‐ pings it has been configured to use. Other applications should treat this key as read-only. See ovn-controller(8) for more in‐ formation. other_config : datapath-type: optional string ovn-controller populates this key with the datapath type config‐ ured in the datapath_type column of the Open_vSwitch database’s Bridge table. Other applications should treat this key as read- only. See ovn-controller(8) for more information. other_config : iface-types: optional string ovn-controller populates this key with the interface types con‐ figured in the iface_types column of the Open_vSwitch database’s Open_vSwitch table. Other applications should treat this key as read-only. See ovn-controller(8) for more information. other_config : ovn-cms-options: optional string ovn-controller populates this key with the set of options con‐ figured in the external_ids:ovn-cms-options column of the Open_vSwitch database’s Open_vSwitch table. See ovn-con‐ troller(8) for more information. other_config : is-interconn: optional string ovn-controller populates this key with the setting configured in the external_ids:ovn-is-interconn column of the Open_vSwitch database’s Open_vSwitch table. If set to true, the chassis is used as an interconnection gateway. See ovn-controller(8) for more information. other_config : is-remote: optional string ovn-ic set this key to true for remote interconnection gateway chassises learned from the interconnection southbound database. See ovn-ic(8) for more information. transport_zones: set of strings ovn-controller populates this key with the transport zones con‐ figured in the external_ids:ovn-transport-zones column of the Open_vSwitch database’s Open_vSwitch table. See ovn-con‐ troller(8) for more information. other_config : ovn-chassis-mac-mappings: optional string ovn-controller populates this key with the set of options con‐ figured in the external_ids:ovn-chassis-mac-mappings column of the Open_vSwitch database’s Open_vSwitch table. See ovn-con‐ troller(8) for more information. other_config : port-up-notif: optional string ovn-controller populates this key with true when it supports Port_Binding.up. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs Encapsulation Configuration: OVN uses encapsulation to transmit logical dataplane packets between chassis. encaps: set of 1 or more Encaps Points to supported encapsulation configurations to transmit logical dataplane packets to this chassis. Each entry is a Encap record that describes the configuration. Gateway Configuration: A gateway is a chassis that forwards traffic between the OVN-managed part of a logical network and a physical VLAN, extending a tunnel-based logical network into a physical network. Gateways are typically dedi‐ cated nodes that do not host VMs and will be controlled by ovn-con‐ troller-vtep. vtep_logical_switches: set of strings Stores all VTEP logical switch names connected by this gateway chassis. The Port_Binding table entry with options:vtep-physi‐ cal-switch equal Chassis name, and options:vtep-logical-switch value in Chassis vtep_logical_switches, will be associated with this Chassis. Chassis_Private TABLE Each row in this table maintains per chassis private data that are ac‐ cessed only by the owning chassis (write only) and ovn-northd, not by any other chassis. These data are stored in this separate table instead of the Chassis table for performance considerations: the rows in this table can be conditionally monitored by chassises so that each chassis only get update notifications for its own row, to avoid unnecessary chassis private data update flooding in a large scale deployment. Summary: name string (must be unique within table) chassis optional weak reference to Chassis nb_cfg integer nb_cfg_timestamp integer Common Columns: external_ids map of string-string pairs Details: name: string (must be unique within table) The name of the chassis that owns these chassis-private data. chassis: optional weak reference to Chassis The reference to Chassis table for the chassis that owns these chassis-private data. nb_cfg: integer Sequence number for the configuration. When ovn-controller up‐ dates the configuration of a chassis from the contents of the southbound database, it copies nb_cfg from the SB_Global table into this column. nb_cfg_timestamp: integer The timestamp when ovn-controller finishes processing the change corresponding to nb_cfg. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs Encap TABLE The encaps column in the Chassis table refers to rows in this table to identify how OVN may transmit logical dataplane packets to this chas‐ sis. Each chassis, via ovn-controller(8) or ovn-controller-vtep(8), adds and updates its own rows and keeps a copy of the remaining rows to determine how to reach other chassis. Summary: type string, one of geneve, stt, or vxlan options map of string-string pairs options : csum optional string, either true or false options : dst_port optional string, containing an integer ip string chassis_name string Details: type: string, one of geneve, stt, or vxlan The encapsulation to use to transmit packets to this chassis. Hypervisors and gateways must use one of: geneve, vxlan, or stt. options: map of string-string pairs Options for configuring the encapsulation, which may be type specific. options : csum: optional string, either true or false csum indicates whether this chassis can transmit and receive packets that include checksums with reasonable performance. It hints to senders transmitting data to this chassis that they should use checksums to protect OVN metadata. ovn-controller populates this key with the value defined in external_ids:ovn- encap-csum column of the Open_vSwitch database’s Open_vSwitch table. Other applications should treat this key as read-only. See ovn-controller(8) for more information. In terms of performance, checksumming actually significantly in‐ creases throughput in most common cases when running on Linux based hosts without NICs supporting encapsulation hardware of‐ fload (around 60% for bulk traffic). The reason is that gener‐ ally all NICs are capable of offloading transmitted and received TCP/UDP checksums (viewed as ordinary data packets and not as tunnels). The benefit comes on the receive side where the vali‐ dated outer checksum can be used to additionally validate an in‐ ner 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 en‐ tire packets in their switching engines and are therefore unable to efficiently compute or validate full packet checksums. In ad‐ dition certain versions of the Linux kernel are not able to fully take advantage of encapsulation NIC offloads in the pres‐ ence of checksums. (This is actually a pretty narrow corner case though: earlier versions of Linux don’t support encapsulation offloads at all and later versions support both offloads and checksums well.) csum defaults to false for hardware VTEPs and true for all other cases. This option applies to geneve and vxlan encapsulations. options : dst_port: optional string, containing an integer If set, overrides the UDP (for geneve and vxlan) or TCP (for stt) destination port. ip: string The IPv4 address of the encapsulation tunnel endpoint. chassis_name: string The name of the chassis that created this encap. Address_Set TABLE This table contains address sets synced from the Address_Set table in the OVN_Northbound database and address sets generated from the Port_Group table in the OVN_Northbound database. See the documentation for the Address_Set table and Port_Group table in the OVN_Northbound database for details. Summary: name string (must be unique within table) addresses set of strings Details: name: string (must be unique within table) addresses: set of strings Port_Group TABLE This table contains names for the logical switch ports in the OVN_Northbound database that belongs to the same group that is defined in Port_Group in the OVN_Northbound database. Summary: name string (must be unique within table) ports set of strings Details: name: string (must be unique within table) ports: set of strings Logical_Flow TABLE Each row in this table represents one logical flow. ovn-northd popu‐ lates this table with logical flows that implement the L2 and L3 topologies specified in the OVN_Northbound database. Each hypervisor, via ovn-controller, translates the logical flows into OpenFlow flows specific to its hypervisor and installs them into Open vSwitch. Logical flows are expressed in an OVN-specific format, described here. A logical datapath flow is much like an OpenFlow flow, except that the flows are written in terms of logical ports and logical datapaths in‐ stead of physical ports and physical datapaths. Translation between logical and physical flows helps to ensure isolation between logical datapaths. (The logical flow abstraction also allows the OVN central‐ ized components to do less work, since they do not have to separately compute and push out physical flows to each chassis.) The default action when no flow matches is to drop packets. Architectural Logical Life Cycle of a Packet This following description focuses on the life cycle of a packet through a logical datapath, ignoring physical details of the implemen‐ tation. Please refer to Architectural Physical Life Cycle of a Packet in ovn-architecture(7) for the physical information. The description here is written as if OVN itself executes these steps, but in fact OVN (that is, ovn-controller) programs Open vSwitch, via OpenFlow and OVSDB, to execute them on its behalf. At a high level, OVN passes each packet through the logical datapath’s logical ingress pipeline, which may output the packet to one or more logical port or logical multicast groups. For each such logical output port, OVN passes the packet through the datapath’s logical egress pipeline, which may either drop the packet or deliver it to the desti‐ nation. 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 or a logical_dp_group, 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 speci‐ fied. Some actions, such as those to modify packet headers, require no further details. The next and output actions are special. The next action causes the above process to be repeated recursively, except that OVN searches for table_id of 1 instead of 0. Similarly, any next action in a row found in that table would cause a further search for a table_id of 2, and so on. When recursive processing completes, flow control returns to the action following next. The output action also introduces recursion. Its effect depends on the current value of the outport field. Suppose outport designates a logi‐ cal port. First, OVN compares inport to outport; if they are equal, it treats the output as a no-op by default. In the common case, where they are different, the packet enters the egress pipeline. This transition to the egress pipeline discards register data, e.g. reg0 ... reg9 and connection tracking state, to achieve uniform behavior regardless of whether the egress pipeline is on a different hypervisor (because reg‐ isters aren’t preserve across tunnel encapsulation). To execute the egress pipeline, OVN again searches the Logical_Flow ta‐ ble for a row with correct logical_datapath or a logical_dp_group, 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, ex‐ cept 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 de‐ scription 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 de‐ scribed in detail in ovn-northd(8). Summary: logical_datapath optional Datapath_Binding logical_dp_group optional Logical_DP_Group pipeline string, either egress or ingress table_id integer, in range 0 to 32 priority integer, in range 0 to 65,535 match string actions string tags map of string-string pairs controller_meter optional 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: optional Datapath_Binding The logical datapath to which the logical flow belongs. logical_dp_group: optional Logical_DP_Group The group of logical datapaths to which the logical flow be‐ longs. This means that the same logical flow belongs to all datapaths in a group. pipeline: string, either egress or ingress The primary flows used for deciding on a packet’s destination are the ingress flows. The egress flows implement ACLs. See Log‐ ical Life Cycle of a Packet, above, for details. table_id: integer, in range 0 to 32 The stage in the logical pipeline, analogous to an OpenFlow ta‐ ble number. priority: integer, in range 0 to 65,535 The flow’s priority. Flows with numerically higher priority take precedence over those with lower. If two logical datapath flows with the same priority both match, then the one actually applied to the packet is undefined. match: string A matching expression. OVN provides a superset of OpenFlow matching capabilities, using a syntax similar to Boolean expres‐ sions in a programming language. The most important components of match expression are compar‐ isons between symbols and constants, e.g. ip4.dst == 192.168.0.1, ip.proto == 6, arp.op == 1, eth.type == 0x800. The logical AND operator && and logical OR operator || can combine comparisons into a larger expression. Matching expressions also support parentheses for grouping, the logical NOT prefix operator !, and literals 0 and 1 to express ``false’’ or ``true,’’ respectively. The latter is useful by it‐ self as a catch-all expression that matches every packet. Match expressions also support a kind of function syntax. The following functions are supported: is_chassis_resident(lport) Evaluates to true on a chassis on which logical port lport (a quoted string) resides, and to false elsewhere. This function was introduced in OVN 2.7. Symbols Type. Symbols have integer or string type. Integer symbols have a width in bits. Kinds. There are three kinds of symbols: • Fields. A field symbol represents a packet header or metadata field. For example, a field named vlan.tci might represent the VLAN TCI field in a packet. A field symbol can have integer or string type. Integer fields can be nominal or ordinal (see Level of Measure‐ ment, below). • Subfields. A subfield represents a subset of bits from a larger field. For example, a field vlan.vid might be de‐ fined as an alias for vlan.tci[0..11]. Subfields are pro‐ vided 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 ex‐ pression. Predicates may be used much like 1-bit fields. For example, ip4 might expand to eth.type == 0x800. Pred‐ icates are provided for syntactic convenience, because it is always possible to instead specify the underlying ex‐ pression directly. A predicate whose expansion refers to any nominal field or predicate (see Level of Measurement, below) is nomi‐ nal; other predicates have Boolean level of measurement. Level of Measurement. See http://en.wikipedia.org/wiki/Level_of_measurement for the sta‐ tistical concept on which this classification is based. There are three levels: • Ordinal. In statistics, ordinal values can be ordered on a scale. OVN considers a field (or subfield) to be ordi‐ nal if its bits can be examined individually. This is true for the OpenFlow fields that OpenFlow or Open vSwitch makes ``maskable.’’ Any use of a ordinal field may specify a single bit or a range of bits, e.g. vlan.tci[13..15] refers to the PCP field within the VLAN TCI, and eth.dst[40] refers to the multicast bit in the Ethernet destination address. OVN supports all the usual arithmetic relations (==, !=, <, <=, >, 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 exam‐ ples: all of these are just identifiers assigned arbi‐ trarily with no deeper meaning. In OpenFlow and Open vSwitch, bits in these fields generally aren’t individu‐ ally addressable. OVN only supports arithmetic tests for equality on nomi‐ nal fields, because OpenFlow and Open vSwitch provide no way for a flow to efficiently implement other comparisons on them. (A test for inequality can be sort of built out of two flows with different priorities, but OVN matching expressions always generate flows with a single prior‐ ity.) String fields are always nominal. • Boolean. A nominal field that has only two values, 0 and 1, is somewhat exceptional, since it is easy to support both equality and inequality tests on such a field: ei‐ ther one can be implemented as a test for 0 or 1. Only predicates (see above) have a Boolean level of mea‐ surement. This isn’t a standard level of measurement. Prerequisites. Any symbol can have prerequisites, which are ad‐ ditional condition implied by the use of the symbol. For exam‐ ple, For example, icmp4.type symbol might have prerequisite icmp4, which would cause an expression icmp4.type == 0 to be in‐ terpreted as icmp4.type == 0 && icmp4, which would in turn ex‐ pand 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 ef‐ ficient than that of the other relational operators. Constants Integer constants may be expressed in decimal, hexadecimal pre‐ fixed by 0x, or as dotted-quad IPv4 addresses, IPv6 addresses in their standard forms, or Ethernet addresses as colon-separated hex digits. A constant in any of these forms may be followed by a slash and a second constant (the mask) in the same form, to form a masked constant. IPv4 and IPv6 masks may be given as in‐ tegers, to express CIDR prefixes. String constants have the same syntax as quoted strings in JSON (thus, they are Unicode strings). Some operators support sets of constants written inside curly braces { ... }. Commas between elements of a set, and after the last elements, are optional. With ==, ``field == { constant1, constant2, ... }’’ is syntactic sugar for ``field == constant1 || field == constant2 || .... Similarly, ``field != { constant1, constant2, ... }’’ is equivalent to ``field != constant1 && field != constant2 && ...’’. You may refer to a set of IPv4, IPv6, or MAC addresses stored in the Address_Set table by its name. An Address_Set with a name of set1 can be referred to as $set1. You may refer to a group of logical switch ports stored in the Port_Group table by its name. An Port_Group with a name of port_group1 can be referred to as @port_group1. Additionally, you may refer to the set of addresses belonging to a group of logical switch ports stored in the Port_Group table by its name followed by a suffix ’_ip4’/’_ip6’. The IPv4 address set of a Port_Group with a name of port_group1 can be referred to as $port_group1_ip4, and the IPv6 address set of the same Port_Group can be referred to as $port_group1_ip6 Miscellaneous Comparisons may name the symbol or the constant first, e.g. tcp.src == 80 and 80 == tcp.src are both acceptable. Tests for a range may be expressed using a syntax like 1024 <= tcp.src <= 49151, which is equivalent to 1024 <= tcp.src && tcp.src <= 49151. For a one-bit field or predicate, a mention of its name is equivalent to symobl == 1, e.g. vlan.present is equivalent to vlan.present == 1. The same is true for one-bit subfields, e.g. vlan.tci[12]. There is no technical limitation to implementing the same for ordinal fields of all widths, but the implementa‐ tion is expensive enough that the syntax parser requires writing an explicit comparison against zero to make mistakes less likely, e.g. in tcp.src != 0 the comparison against 0 is re‐ quired. 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 || re‐ quire 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 */. Mul‐ tiline comments are not supported. Symbols Most of the symbols below have integer type. Only inport and outport have string type. inport names a logical port. Thus, its value is a logical_port name from the Port_Binding table. out‐ port may name a logical port, as inport, or a logical multicast group defined in the Multicast_Group table. For both symbols, only names within the flow’s logical datapath may be used. The regX symbols are 32-bit integers. The xxregX symbols are 128-bit integers, which overlay four of the 32-bit registers: xxreg0 overlays reg0 through reg3, with reg0 supplying the most- significant bits of xxreg0 and reg3 the least-significant. xxreg1 similarly overlays reg4 through reg7. • reg0...reg9 • xxreg0 xxreg1 • inport outport • flags.loopback • pkt.mark • eth.src eth.dst eth.type • vlan.tci vlan.vid vlan.pcp vlan.present • ip.proto ip.dscp ip.ecn ip.ttl ip.frag • ip4.src ip4.dst • ip6.src ip6.dst ip6.label • arp.op arp.spa arp.tpa arp.sha arp.tha • tcp.src tcp.dst tcp.flags • udp.src udp.dst • sctp.src sctp.dst • icmp4.type icmp4.code • icmp6.type icmp6.code • nd.target nd.sll nd.tll • ct_mark ct_label • ct_state, which has several Boolean subfields. The ct_next action initializes the following subfields: • ct.trk: Always set to true by ct_next to indicate that connection tracking has taken place. All other ct subfields have ct.trk as a prerequisite. • ct.new: True for a new flow • ct.est: True for an established flow • ct.rel: True for a related flow • ct.rpl: True for a reply flow • ct.inv: True for a connection entry in a bad state The ct_dnat, ct_snat, and ct_lb actions initialize the following subfields: • ct.dnat: True for a packet whose destination IP address has been changed. • ct.snat: True for a packet whose source IP address has been changed. The following predicates are supported: • eth.bcast expands to eth.dst == ff:ff:ff:ff:ff:ff • eth.mcast expands to eth.dst[40] • vlan.present expands to vlan.tci[12] • ip4 expands to eth.type == 0x800 • ip4.src_mcast expands to ip4.src[28..31] == 0xe • ip4.mcast expands to ip4.dst[28..31] == 0xe • ip6 expands to eth.type == 0x86dd • ip expands to ip4 || ip6 • icmp4 expands to ip4 && ip.proto == 1 • icmp6 expands to ip6 && ip.proto == 58 • icmp expands to icmp4 || icmp6 • ip.is_frag expands to ip.frag[0] • ip.later_frag expands to ip.frag[1] • ip.first_frag expands to ip.is_frag && !ip.later_frag • arp expands to eth.type == 0x806 • nd expands to icmp6.type == {135, 136} && icmp6.code == 0 && ip.ttl == 255 • nd_ns expands to icmp6.type == 135 && icmp6.code == 0 && ip.ttl == 255 • nd_na expands to icmp6.type == 136 && icmp6.code == 0 && ip.ttl == 255 • nd_rs expands to icmp6.type == 133 && icmp6.code == 0 && ip.ttl == 255 • nd_ra expands to icmp6.type == 134 && icmp6.code == 0 && ip.ttl == 255 • tcp expands to ip.proto == 6 • udp expands to ip.proto == 17 • sctp expands to ip.proto == 132 actions: string Logical datapath actions, to be executed when the logical flow represented by this row is the highest-priority match. Actions share lexical syntax with the match column. An empty set of actions (or one that contains just white space or comments), or a set of actions that consists of just drop;, causes the matched packets to be dropped. Otherwise, the column should con‐ tain a sequence of actions, each terminated by a semicolon. The following actions are defined: output; In the ingress pipeline, this action executes the egress pipeline as a subroutine. If outport names a logical port, the egress pipeline executes once; if it is a mul‐ ticast group, the egress pipeline runs once for each log‐ ical port in the group. In the egress pipeline, this action performs the actual output to the outport logical port. (In the egress 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. Ac‐ tions in the both ingress and egress pipeline can use next to jump across the other pipeline. Actions in the ingress pipeline should use next to jump into the specific table of egress pipeline only if it is certain that the packets are local and not tunnelled and wants to skip certain stages in the packet processing. field = constant; Sets data or metadata field field to constant value con‐ stant, e.g. outport = "vif0"; to set the logical output port. To set only a subset of bits in a field, specify a subfield for field or a masked constant, e.g. one may use vlan.pcp[2] = 1; or vlan.pcp = 4/4; to set the most signif‐ icant bit of the VLAN PCP. Assigning to a field with prerequisites implicitly adds those prerequisites to match; thus, for example, a flow that sets tcp.dst applies only to TCP flows, regardless of whether its match mentions any TCP field. Not all fields are modifiable (e.g. eth.type and ip.proto are read-only), and not all modifiable fields may be par‐ tially modified (e.g. ip.ttl must assigned as a whole). The outport field is modifiable in the ingress pipeline but not in the egress pipeline. ovn_field = constant; Sets OVN field ovn_field to constant value constant. OVN supports setting the values of certain fields which are not yet supported in OpenFlow to set or modify them. Below are the supported OVN fields: • icmp4.frag_mtu icmp6.frag_mtu This field sets the low-order 16 bits of the ICMP{4,6} header field that is labelled "unused" in the ICMP specification as defined in the RFC 1191 with the value specified in constant. Eg. icmp4.frag_mtu = 1500; field1 = field2; Sets data or metadata field field1 to the value of data or metadata field field2, e.g. reg0 = ip4.src; copies ip4.src into reg0. To modify only a subset of a field’s bits, spec‐ ify a subfield for field1 or field2 or both, e.g. vlan.pcp = reg0[0..2]; copies the least-significant bits of reg0 into the VLAN PCP. field1 and field2 must be the same type, either both string or both integer fields. If they are both integer fields, they must have the same width. If field1 or field2 has prerequisites, they are added im‐ plicitly 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. push(field); Push the value of field to the stack top. pop(field); Pop the stack top and store the value to field, which must be modifiable. ip.ttl--; Decrements the IPv4 or IPv6 TTL. If this would make the TTL zero or negative, then processing of the packet halts; no further actions are processed. (To properly handle such cases, a higher-priority flow should match on ip.ttl == {0, 1};.) Prerequisite: ip ct_next; Apply connection tracking to the flow, initializing ct_state for matching in later tables. Automatically moves on to the next table, as if followed by next. As a side effect, IP fragments will be reassembled for matching. If a fragmented packet is output, then it will be sent with any overlapping fragments squashed. The connec‐ tion tracking state is scoped by the logical port when the action is used in a flow for a logical switch, so overlap‐ ping addresses may be used. To allow traffic related to the matched flow, execute ct_commit . Connection tracking state is scoped by the logical topology when the action is used in a flow for a router. It is possible to have actions follow ct_next, but they will not have access to any of its side-effects and is not generally useful. ct_commit { }; ct_commit { ct_mark=value[/mask]; }; ct_commit { ct_label=value[/mask]; }; ct_commit { ct_mark=value[/mask]; ct_label=value[/mask]; }; Commit the flow to the connection tracking entry associated with it by a previous call to ct_next. When ct_mark=value[/mask] and/or ct_label=value[/mask] are sup‐ plied, ct_mark and/or ct_label will be set to the values indicated by value[/mask] on the connection tracking entry. ct_mark is a 32-bit field. ct_label is a 128-bit field. The value[/mask] should be specified in hex string if more than 64bits are to be used. Registers and other named fields can be used for value. ct_mark and ct_label may be sub-ad‐ dressed in order to have specific bits set. Note that if you want processing to continue in the next table, you must execute the next action after ct_commit. You may also leave out next which will commit connection tracking state, and then drop the packet. This could be useful for setting ct_mark on a connection tracking entry before dropping a packet, for example. ct_dnat; ct_dnat(IP); ct_dnat sends the packet through the DNAT zone in connec‐ tion tracking table to unDNAT any packet that was DNATed in the opposite direction. The packet is then automatically sent to to the next tables as if followed by next; action. The next tables will see the changes in the packet caused by the connection tracker. ct_dnat(IP) sends the packet through the DNAT zone to change the destination IP address of the packet to the one provided inside the parentheses and commits the connection. The packet is then automatically sent to the next tables as if followed by next; action. The next tables will see the changes in the packet caused by the connection tracker. ct_snat; ct_snat(IP); ct_snat sends the packet through the SNAT zone to unSNAT any packet that was SNATed in the opposite direction. The packet is automatically sent to the next tables as if fol‐ lowed by the next; action. The next tables will see the changes in the packet caused by the connection tracker. ct_snat(IP) sends the packet through the SNAT zone to change the source IP address of the packet to the one pro‐ vided inside the parenthesis and commits the connection. The packet is then automatically sent to the next tables as if followed by next; action. The next tables will see the changes in the packet caused by the connection tracker. ct_dnat_in_czone; ct_dnat_in_czone(IP); ct_dnat_in_czone sends the packet through the common NAT zone (used for both DNAT and SNAT) 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_in_czone(IP) sends the packet through the common NAT 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_in_czone; ct_snat_in_czone(IP); ct_snat_in_czone sends the packet through the common NAT zone to unSNAT any packet that was SNATed in the opposite direction. The packet is automatically sent to the next ta‐ bles as if followed by the next; action. The next tables will see the changes in the packet caused by the connection tracker. ct_snat_in_czone(IP) sends the packet\ through the common NAT 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. ct_commit_nat; Applies NAT and commits the connection to the CT. Automati‐ cally moves on to the next table, as if followed by next. This is very useful for connections that are in related state for already existing connections and allows the NAT to be applied to them as well. clone { action; ... }; Makes a copy of the packet being processed and executes each action on the copy. Actions following the clone ac‐ tion, if any, apply to the original, unmodified packet. This can be used as a way to ``save and restore’’ the packet around a set of actions that may modify it and should not persist. arp { action; ... }; Temporarily replaces the IPv4 packet being processed by an ARP packet and executes each nested action on the ARP packet. Actions following the arp action, if any, apply to the original, unmodified packet. The ARP packet that this action operates on is initialized based on the IPv4 packet being processed, as follows. These are default values that the nested actions will probably want to change: • eth.src unchanged • eth.dst unchanged • eth.type = 0x0806 • arp.op = 1 (ARP request) • arp.sha copied from eth.src • arp.spa copied from ip4.src • arp.tha = 00:00:00:00:00:00 • arp.tpa copied from ip4.dst The ARP packet has the same VLAN header, if any, as the IP packet it replaces. Prerequisite: ip4 get_arp(P, A); Parameters: logical port string field P, 32-bit IP address field A. Looks up A in P’s mac binding table. If an entry is found, stores its Ethernet address in eth.dst, otherwise stores 00:00:00:00:00:00 in eth.dst. Example: get_arp(outport, ip4.dst); put_arp(P, A, E); Parameters: logical port string field P, 32-bit IP address field A, 48-bit Ethernet address field E. Adds or updates the entry for IP address A in logical port P’s mac binding table, setting its Ethernet address to E. Example: put_arp(inport, arp.spa, arp.sha); R = lookup_arp(P, A, M); Parameters: logical port string field P, 32-bit IP address field A, 48-bit MAC address field M. Result: stored to a 1-bit subfield R. Looks up A and M in P’s mac binding table. If an entry is found, stores 1 in the 1-bit subfield R, else 0. Example: reg0[0] = lookup_arp(inport, arp.spa, arp.sha); R = lookup_arp_ip(P, A); Parameters: logical port string field P, 32-bit IP address field A. Result: stored to a 1-bit subfield R. Looks up A in P’s mac binding table. If an entry is found, stores 1 in the 1-bit subfield R, else 0. Example: reg0[0] = lookup_arp_ip(inport, arp.spa); P = get_fdb(A); Parameters:48-bit MAC address field A. Looks up A in fdb table. If an entry is found, stores the logical port key to the out parameter P. Example: outport = get_fdb(eth.src); put_fdb(P, A); Parameters: logical port string field P, 48-bit MAC address field A. Adds or updates the entry for Ethernet address A in fdb ta‐ ble, setting its logical port key to P. Example: put_fdb(inport, arp.spa); R = lookup_fdb(P, A); Parameters: 48-bit MAC address field M, logical port string field P. Result: stored to a 1-bit subfield R. Looks up A in fdb table. If an entry is found and the the logical port key is P, P, stores 1 in the 1-bit subfield R, else 0. Example: reg0[0] = lookup_fdb(inport, eth.src); nd_ns { action; ... }; Temporarily replaces the IPv6 packet being processed by an IPv6 Neighbor Solicitation packet and executes each nested action on the IPv6 NS packet. Actions following the nd_ns action, if any, apply to the original, unmodified packet. The IPv6 NS packet that this action operates on is initial‐ ized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will prob‐ ably want to change: • eth.src unchanged • eth.dst set to IPv6 multicast MAC address • eth.type = 0x86dd • ip6.src copied from ip6.src • ip6.dst set to IPv6 Solicited-Node multicast address • icmp6.type = 135 (Neighbor Solicitation) • nd.target copied from ip6.dst The IPv6 NS packet has the same VLAN header, if any, as the IP packet it replaces. Prerequisite: ip6 nd_na { action; ... }; Temporarily replaces the IPv6 neighbor solicitation packet being processed by an IPv6 neighbor advertisement (NA) packet and executes each nested action on the NA packet. Actions following the nd_na action, if any, apply to the original, unmodified packet. The NA packet that this action operates on is initialized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will probably want to change: • eth.dst exchanged with eth.src • eth.type = 0x86dd • ip6.dst copied from ip6.src • ip6.src copied from nd.target • icmp6.type = 136 (Neighbor Advertisement) • nd.target unchanged • nd.sll = 00:00:00:00:00:00 • nd.tll copied from eth.dst The ND packet has the same VLAN header, if any, as the IPv6 packet it replaces. Prerequisite: nd_ns nd_na_router { action; ... }; Temporarily replaces the IPv6 neighbor solicitation packet being processed by an IPv6 neighbor advertisement (NA) packet, sets ND_NSO_ROUTER in the RSO flags and executes each nested action on the NA packet. Actions following the nd_na_router action, if any, apply to the original, unmodi‐ fied packet. The NA packet that this action operates on is initialized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will probably want to change: • eth.dst exchanged with eth.src • eth.type = 0x86dd • ip6.dst copied from ip6.src • ip6.src copied from nd.target • icmp6.type = 136 (Neighbor Advertisement) • nd.target unchanged • nd.sll = 00:00:00:00:00:00 • nd.tll copied from eth.dst The ND packet has the same VLAN header, if any, as the IPv6 packet it replaces. Prerequisite: nd_ns get_nd(P, A); Parameters: logical port string field P, 128-bit IPv6 ad‐ dress 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 ad‐ dress field A, 48-bit Ethernet address field E. Adds or updates the entry for IPv6 address A in logical port P’s mac binding table, setting its Ethernet address to E. Example: put_nd(inport, nd.target, nd.tll); R = lookup_nd(P, A, M); Parameters: logical port string field P, 128-bit IP address field A, 48-bit MAC address field M. Result: stored to a 1-bit subfield R. Looks up A and M in P’s mac binding table. If an entry is found, stores 1 in the 1-bit subfield R, else 0. Example: reg0[0] = lookup_nd(inport, ip6.src, eth.src); R = lookup_nd_ip(P, A); Parameters: logical port string field P, 128-bit IP address field A. Result: stored to a 1-bit subfield R. Looks up A in P’s mac binding table. If an entry is found, stores 1 in the 1-bit subfield R, else 0. Example: reg0[0] = lookup_nd_ip(inport, ip6.src); R = put_dhcp_opts(D1 = V1, D2 = V2, ..., Dn = Vn); Parameters: one or more DHCP option/value pairs, which must include an offerip option (with code 0). Result: stored to a 1-bit subfield R. Valid only in the ingress pipeline. When this action is applied to a DHCP request packet (DHCPDISCOVER or DHCPREQUEST), it changes the packet into a DHCP reply (DHCPOFFER or DHCPACK, respectively), replaces the options by those specified as parameters, and stores 1 in R. When this action is applied to a non-DHCP packet or a DHCP packet that is not DHCPDISCOVER or DHCPREQUEST, it leaves the packet unchanged and stores 0 in R. The contents of the DHCP_Option table control the DHCP op‐ tion 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 op‐ tions 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 un‐ changed 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 ac‐ tion. 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(backends=ip[:port][,...][; hash_fields=field1,field2,...][; ct_flag]); With arguments, ct_lb commits the packet to the connection tracking table and DNATs the packet’s destination IP ad‐ dress (and port) to the IP address or addresses (and op‐ tional ports) specified in the backends. If multiple comma- separated IP addresses are specified, each is given equal weight for picking the DNAT address. By default, dp_hash is used as the OpenFlow group selection method, but if hash_fields is specified, hash is used as the selection method, and the fields listed are used as the hash fields. The ct_flag field represents one of supported flag: skip_snat or force_snat, this flag will be stored in ct_la‐ bel register. Without arguments, ct_lb sends the packet to the connection tracking table to NAT the packets. If the packet is part of an established connection that was previously committed to the connection tracker via ct_lb(...), it will automati‐ cally get DNATed to the same IP address as the first packet in that connection. 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. ct_lb_mark; ct_lb_mark(backends=ip[:port][,...][; hash_fields=field1,field2,...][; ct_flag]); Same as ct_lb, except that it internally uses ct_mark to store the NAT flag, while ct_lb uses ct_label for the same purpose. 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 re‐ solve 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 re‐ quest 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 op‐ tion/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 Ad‐ vertisement 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 op‐ tion can be defined multiple times. Result: stored to a 1-bit subfield R. Valid only in the ingress pipeline. When this action is applied to an IPv6 Router solicitation request packet, it changes the packet into an IPv6 Router Advertisement reply and adds the options specified in the parameters, and stores 1 in R. When this action is applied to a non-IPv6 Router solicita‐ tion packet or an invalid IPv6 request packet , it leaves the packet unchanged and stores 0 in R. Example: reg0[3] = put_nd_ra_opts(addr_mode = "slaac", slla = 00:00:00:00:10:02, prefix = aef0::/64, mtu = 1450); set_meter(rate); set_meter(rate, burst); Parameters: rate limit int field rate in kbps, burst rate limits int field burst in kbps. This action sets the rate limit for a flow. Example: set_meter(100, 1000); R = check_pkt_larger(L) Parameters: packet length L to check for in bytes. Result: stored to a 1-bit subfield R. This is a logical equivalent of the OpenFlow check_pkt_larger action. If the packet is larger than the length specified in L, it stores 1 in the subfield R. Example: reg0[6] = check_pkt_larger(1000); log(key=value, ...); Causes ovn-controller to log the packet on the chassis that processes it. Packet logging currently uses the same logging mechanism as other Open vSwitch and OVN messages, which means that whether and where log messages appear depends on the local logging configuration that can be configured with ovs-appctl, etc. The log action takes zero or more of the following key- value pair arguments that control what is logged: name=string An optional name for the ACL. The string is cur‐ rently limited to 64 bytes. severity=level Indicates the severity of the event. The level is one of following (from more to less serious): alert, warning, notice, info, or debug. If a severity is not provided, the default is info. verdict=value The verdict for packets matching the flow. The value must be one of allow, deny, or reject. meter=string An optional rate-limiting meter to be applied to the logs. The string should reference a name entry from the Meter table. The only meter action that is appropriate is drop. fwd_group(liveness=bool, childports=port, ...); Parameters: optional liveness, either true or false, de‐ faulting to false; childports, a comma-delimited list of strings denoting logical ports to load balance across. Load balance traffic to one or more child ports in a log‐ ical switch. ovn-controller translates the fwd_group into an OpenFlow group with one bucket for each child port. If liveness=true is specified, it also integrates the bucket selection with BFD status on the tunnel interface corre‐ sponding to child port. Example: fwd_group(liveness=true, childports="p1", "p2"); icmp4 { action; ... }; icmp4_error { action; ... }; Temporarily replaces the IPv4 packet being processed by an ICMPv4 packet and executes each nested action on the ICMPv4 packet. Actions following these actions, if any, apply to the original, unmodified packet. The ICMPv4 packet that these actions operates on is ini‐ tialized based on the IPv4 packet being processed, as fol‐ lows. These are default values that the nested actions will probably want to change. Ethernet and IPv4 fields not listed here are not changed: • ip.proto = 1 (ICMPv4) • ip.frag = 0 (not a fragment) • ip.ttl = 255 • icmp4.type = 3 (destination unreachable) • icmp4.code = 1 (host unreachable) icmp4_error action is expected to be used to generate an ICMPv4 packet in response to an error in original IP packet. When this action generates the ICMPv4 packet, it also copies the original IP datagram following the ICMPv4 header as per RFC 1122: 3.2.2. Prerequisite: ip4 icmp6 { action; ... }; icmp6_error { action; ... }; Temporarily replaces the IPv6 packet being processed by an ICMPv6 packet and executes each nested action on the ICMPv6 packet. Actions following the icmp6 action, if any, apply to the original, unmodified packet. The ICMPv6 packet that this action operates on is initial‐ ized based on the IPv6 packet being processed, as follows. These are default values that the nested actions will prob‐ ably want to change. Ethernet and IPv6 fields not listed here are not changed: • ip.proto = 58 (ICMPv6) • ip.ttl = 255 • icmp6.type = 1 (destination unreachable) • icmp6.code = 1 (administratively prohibited) icmp6_error action is expected to be used to generate an ICMPv6 packet in response to an error in original IPv6 packet. 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 reject { action; ... }; If the original packet is IPv4 or IPv6 TCP packet, it re‐ places it with IPv4 or IPv6 TCP RST packet and executes the inner actions. Otherwise it replaces it with an ICMPv4 or ICMPv6 packet and executes the inner actions. The inner actions should not attempt to swap eth source with eth destination and IP source with IP destination as this action implicitly does that. trigger_event; This action is used to allow ovs-vswitchd to report CMS re‐ lated events writing them in Controller_Event table. It is possible to associate a meter to a each event in order to not overload pinctrl thread under heavy load; each meter is identified though a defined naming convention. Supported events: • empty_lb_backends. This event is raised if a re‐ ceived packet is destined for a load balancer VIP that has no configured backend destinations. For this event, the event info includes the load bal‐ ancer VIP, the load balancer UUID, and the transport protocol. Associated meter: event-elb igmp; This action sends the packet to ovn-controller for multi‐ cast snooping. Prerequisite: igmp bind_vport(V, P); Parameters: logical port string field V of type virtual, logical port string field P. Binds the virtual logical port V and sets the chassis col‐ umn and virtual_parent of the table Port_Binding. vir‐ tual_parent is set to P. handle_svc_check(P); Parameters: logical port string field P. Handles the service monitor reply received from the VIF of the logical port P. ovn-controller periodically sends out the service monitor packets for the services configured in the Service_Monitor table and this action updates the sta‐ tus of those services. Example: handle_svc_check(inport); handle_dhcpv6_reply; Handle DHCPv6 prefix delegation advertisements/replies from a IPv6 delegation server. ovn-controller will add an entry ipv6_ra_pd_list in the options table for each prefix re‐ ceived from the delegation server R = select(N1[=W1], N2[=W2], ...); Parameters: Integer N1, N2..., with optional weight W1, W2, ... Result: stored to a logical field or subfield R. Select from a list of integers N1, N2..., each within the range 0 ~ 65535, and store the selected one in the field R. There must be 2 or more integers listed, each with an op‐ tional weight, which is an integer within the range 1 ~ 65535. If weight is not specified, it defaults to 100. The selection method is based on the 5-tuple hash of packet header. Processing automatically moves on to the next table, as if next; were specified. The select action must be put as the last action of the logical flow when there are multiple ac‐ tions (actions put after select will not take effect). Example: reg8[16..31] = select(1=20, 2=30, 3=50); handle_dhcpv6_reply; This action is used to parse DHCPv6 replies from IPv6 Dele‐ gation Router and managed IPv6 Prefix delegation state ma‐ chine R = chk_lb_hairpin(); This action checks if the packet under consideration was destined to a load balancer VIP and it is hairpinned, i.e., after load balancing the destination IP matches the source IP. If it is so, then the 1-bit destination register R is set to 1. R = chk_lb_hairpin_reply(); This action checks if the packet under consideration is from one of the backend IP of a load balancer VIP and the destination IP is the load balancer VIP. If it is so, then the 1-bit destination register R is set to 1. R = ct_snat_to_vip; This action sends the packet through the SNAT zone to change the source IP address of the packet to the load bal‐ ancer VIP if the original destination IP was load balancer VIP and commits the connection. This action applies suc‐ cessfully only for the hairpinned traffic i.e if the action chk_lb_hairpin returned success. This action doesn’t take any arguments and it determines the SNAT IP internally. The packet is not automatically sent to the next table. The caller has to execute the next; action explicitly after this action to advance the packet to the next stage. tags: map of string-string pairs Key-value pairs that provide additional information to help ovn- controller processing the logical flow. Below are the tags used by ovn-controller. in_out_port In the logical flow’s "match" column, if a logical port P is compared with "inport" and the logical flow is on a logical switch ingress pipeline, or if P is compared with "outport" and the logical flow is on a logical switch egress pipeline, and the expression is combined with other expressions (if any) using the operator &&, then the port P should be added as the value in this tag. If there are multiple logical ports meeting this criteria, one of them can be added. ovn-controller uses this infor‐ mation to skip parsing flows that are not needed on the chassis. Failing to add the tag will affect efficiency, while adding wrong value will affect correctness. controller_meter: optional string The name of the meter in table Meter to be used for all packets that the logical flow might send to ovn-controller. external_ids : stage-name: optional string Human-readable name for this flow’s stage in the pipeline. external_ids : stage-hint: optional string, containing an uuid UUID of a OVN_Northbound record that caused this logical flow to be created. Currently used only for attribute of logical flows to northbound ACL records. external_ids : source: optional string Source file and line number of the code that added this flow to the pipeline. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs Logical_DP_Group TABLE Each row in this table represents a group of logical datapaths refer‐ enced by the logical_dp_group column in the Logical_Flow table. Summary: datapaths set of weak reference to Datapath_Bind‐ ings Details: datapaths: set of weak reference to Datapath_Bindings List of Datapath_Binding entries. Multicast_Group TABLE The rows in this table define multicast groups of logical ports. Multi‐ cast groups allow a single packet transmitted over a tunnel to a hyper‐ visor to be delivered to multiple VMs on that hypervisor, which uses bandwidth more efficiently. Each row in this table defines a logical multicast group numbered tun‐ nel_key within datapath, whose logical ports are listed in the ports column. Summary: datapath Datapath_Binding tunnel_key integer, in range 32,768 to 65,535 name string ports set of 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 weak reference to Port_Bindings The logical ports included in the multicast group. All of these ports must be in the datapath logical datapath (but the database schema cannot enforce this). Meter TABLE Each row in this table represents a meter that can be used for QoS or rate-limiting. Summary: name string (must be unique within table) unit string, either kbps or pktps bands set of 1 or more Meter_Bands Details: name: string (must be unique within table) A name for this meter. Names that begin with "__" (two underscores) are reserved for OVN internal use and should not be added manually. unit: string, either kbps or pktps The unit for rate and burst_rate parameters in the bands entry. kbps specifies kilobits per second, and pktps specifies packets per second. bands: set of 1 or more Meter_Bands The bands associated with this meter. Each band specifies a rate above which the band is to take the action action. If multiple bands’ rates are exceeded, then the band with the highest rate among the exceeded bands is selected. Meter_Band TABLE Each row in this table represents a meter band which specifies the rate above which the configured action should be applied. These bands are referenced by the bands column in the Meter table. Summary: action string, must be drop rate integer, in range 1 to 4,294,967,295 burst_size integer, in range 0 to 4,294,967,295 Details: action: string, must be drop The action to execute when this band matches. The only supported action is drop. rate: integer, in range 1 to 4,294,967,295 The rate limit for this band, in kilobits per second or bits per second, depending on whether the parent Meter entry’s unit col‐ umn specified kbps or pktps. burst_size: integer, in range 0 to 4,294,967,295 The maximum burst allowed for the band in kilobits or packets, depending on whether kbps or pktps was selected in the parent Meter entry’s unit column. If the size is zero, the switch is free to select some reasonable value depending on its configura‐ tion. Datapath_Binding TABLE Each row in this table represents a logical datapath, which implements a logical pipeline among the ports in the Port_Binding table associated with it. In practice, the pipeline in a given logical datapath imple‐ ments either a logical switch or a logical router. The main purpose of a row in this table is provide a physical binding for a logical datapath. A logical datapath does not have a physical lo‐ cation, so its physical binding information is limited: just tun‐ nel_key. The rest of the data in this table does not affect packet for‐ warding. Summary: tunnel_key integer, in range 1 to 16,777,215 (must be unique within table) load_balancers set of uuids OVN_Northbound Relationship: external_ids : logical-switch optional string, containing an uuid external_ids : logical-router optional string, containing an uuid external_ids : interconn-ts optional string Naming: external_ids : name optional string external_ids : name2 optional string Common Columns: external_ids map of string-string pairs Details: tunnel_key: integer, in range 1 to 16,777,215 (must be unique within table) The tunnel key value to which the logical datapath is bound. The Tunnel Encapsulation section in ovn-architecture(7) describes how tunnel keys are constructed for each supported encapsula‐ tion. load_balancers: set of uuids Not used anymore; kept for backwards compatibility of the schema. OVN_Northbound Relationship: Each row in Datapath_Binding is associated with some logical datapath. ovn-northd uses these keys to track the association of a logical data‐ path with concepts in the OVN_Northbound database. external_ids : logical-switch: optional string, containing an uuid For a logical datapath that represents a logical switch, ovn-northd stores in this key the UUID of the corresponding Log‐ ical_Switch row in the OVN_Northbound database. external_ids : logical-router: optional string, containing an uuid For a logical datapath that represents a logical router, ovn-northd stores in this key the UUID of the corresponding Log‐ ical_Router row in the OVN_Northbound database. external_ids : interconn-ts: optional string For a logical datapath that represents a logical switch that represents a transit switch for interconnection, ovn-northd stores in this key the value of the same interconn-ts key of the external_ids column of the corresponding Logical_Switch row in the OVN_Northbound database. Naming: ovn-northd copies these from the name fields in the OVN_Northbound database, either from name and external_ids:neutron:router_name in the Logical_Router table or from name and external_ids:neutron:network_name in the Logical_Switch table. external_ids : name: optional string A name for the logical datapath. external_ids : name2: optional string Another name for the logical datapath. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs Port_Binding TABLE Each row in this table binds a logical port to a realization. For most logical ports, this means binding to some physical location, for exam‐ ple by binding a logical port to a VIF that belongs to a VM running on a particular hypervisor. Other logical ports, such as logical patch ports, can be realized without a specific physical location, but their bindings are still expressed through rows in this table. For every Logical_Switch_Port record in OVN_Northbound database, ovn-northd creates a record in this table. ovn-northd populates and maintains every column except the chassis and virtual_parent columns, which it leaves empty in new records. ovn-controller/ovn-controller-vtep populates the chassis column for the records that identify the logical ports that are located on its hyper‐ visor/gateway, which ovn-controller/ovn-controller-vtep in turn finds out by monitoring the local hypervisor’s Open_vSwitch database, which identifies logical ports via the conventions described in Integra‐ tionGuide.rst. (The exceptions are for Port_Binding records with type of l3gateway, whose locations are identified by ovn-northd via the op‐ tions:l3gateway-chassis column in this table. ovn-controller is still responsible to populate the chassis column.) ovn-controller also populates the virtual_parent column of records whose type is virtual. When a chassis shuts down gracefully, it should clean up the chassis column that it previously had populated. (This is not critical because resources hosted on the chassis are equally unreachable regardless of whether their rows are present.) To handle the case where a VM is shut down abruptly on one chassis, then brought up again on a different one, ovn-controller/ovn-controller-vtep must overwrite the chassis column with new information. Summary: Core Features: datapath Datapath_Binding logical_port string (must be unique within table) encap optional weak reference to Encap chassis optional weak reference to Chassis gateway_chassis set of Gateway_Chassises ha_chassis_group optional HA_Chassis_Group up optional boolean tunnel_key integer, in range 1 to 32,767 mac set of strings type string requested_chassis optional weak reference to Chassis Patch Options: options : peer optional string nat_addresses set of strings L3 Gateway Options: options : peer optional string options : l3gateway-chassis 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 : iface-id-ver optional string options : qos_min_rate 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 Distributed Gateway Port Options: options : chassis-redirect-port optional string Chassis Redirect Options: options : distributed-port optional string options : redirect-type optional string options : always-redirect optional string Nested Containers: parent_port optional string tag optional integer, in range 1 to 4,095 Virtual ports: virtual_parent optional string Naming: external_ids : name optional string Common Columns: external_ids map of string-string pairs Details: Core Features: datapath: Datapath_Binding The logical datapath to which the logical port belongs. logical_port: string (must be unique within table) A logical port. For a logical switch port, this is taken from name in the OVN_Northbound database’s Logical_Switch_Port table. For a logical router port, this is taken from name in the OVN_Northbound database’s Logical_Router_port table. (This means that logical switch ports and router port names must not share names in an OVN deployment.) OVN does not prescribe a particular format for the logical port ID. encap: optional weak reference to Encap Points to supported encapsulation configurations to transmit logical dataplane packets to this chassis. Each entry is a Encap record that describes the configuration. chassis: optional weak reference to Chassis The meaning of this column depends on the value of the type col‐ umn. This is the meaning for each type (empty string) The physical location of the logical port. To success‐ fully identify a chassis, this column must be a Chassis record. This is populated by ovn-controller. vtep The physical location of the hardware_vtep gateway. To successfully identify a chassis, this column must be a Chassis record. This is populated by ovn-controller-vtep. localnet Always empty. A localnet port is realized on every chas‐ sis that has connectivity to the corresponding physical network. localport Always empty. A localport port is present on every chas‐ sis. l3gateway The physical location of the L3 gateway. To successfully identify a chassis, this column must be a Chassis record. This is populated by ovn-controller based on the value of the options:l3gateway-chassis column in this table. l2gateway The physical location of this L2 gateway. To successfully identify a chassis, this column must be a Chassis record. This is populated by ovn-controller based on the value of the options:l2gateway-chassis column in this table. gateway_chassis: set of Gateway_Chassises A list of Gateway_Chassis. This should only be populated for ports with type set to chas‐ sisredirect. This column defines the list of chassis used as gateways where traffic will be redirected through. ha_chassis_group: optional HA_Chassis_Group This should only be populated for ports with type set to chas‐ sisredirect. This column defines the HA chassis group with a list of HA chassis used as gateways where traffic will be redi‐ rected through. up: optional boolean This is set to true whenever all OVS flows required by this Port_Binding have been installed. This is populated by ovn-con‐ troller. tunnel_key: integer, in range 1 to 32,767 A number that represents the logical port in the key (e.g. STT key or Geneve TLV) field carried within tunnel protocol packets. The tunnel ID must be unique within the scope of a logical data‐ path. mac: set of strings This column is a misnomer as it may contain MAC addresses and IP addresses. It is copied from the addresses column in the Logi‐ cal_Switch_Port table in the Northbound database. It follows the same format as that column. type: string A type for this logical port. Logical ports can be used to model other types of connectivity into an OVN logical switch. The fol‐ lowing types are defined: (empty string) VM (or VIF) interface. patch One of a pair of logical ports that act as if connected by a patch cable. Useful for connecting two logical data‐ paths, e.g. to connect a logical router to a logical switch or to another logical router. l3gateway One of a pair of logical ports that act as if connected by a patch cable across multiple chassis. Useful for con‐ necting a logical switch with a Gateway router (which is only resident on a particular chassis). localnet A connection to a locally accessible network from ovn-controller instances that have a corresponding bridge mapping. A logical switch can have multiple localnet ports attached. This type is used to model direct connec‐ tivity to existing networks. In this case, each chassis should have a mapping for one of the physical networks only. Note: nothing said above implies that a chassis cannot be plugged to multiple physical networks as long as they belong to different switches. localport A connection to a local VIF. Traffic that arrives on a localport is never forwarded over a tunnel to another chassis. These ports are present on every chassis and have the same address in all of them. This is used to model connectivity to local services that run on every hypervisor. l2gateway 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 op‐ tions: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 log‐ ical port of type chassisredirect. This will cause the packet to be directed to a specific chassis to carry out the egress pipeline. At the beginning of the egress pipeline, the outport will be reset to the value of the distributed port. virtual Represents a logical port with an virtual ip. This vir‐ tual ip can be configured on a logical port (which is refered as virtual parent). requested_chassis: optional weak reference to Chassis This column exists so that the ovn-controller can effectively monitor all Port_Binding records destined for it, and is a sup‐ plement to the options:requested-chassis option. The option is still required so that the ovn-controller can check the CMS in‐ tent when the chassis pointed to does not currently exist, which for example occurs when the ovn-controller is stopped without passing the -restart argument. This column must be a Chassis record. This is populated by ovn-northd when the options:re‐ quested-chassis is defined and contains a string matching the name or hostname of an existing chassis. Patch Options: These options apply to logical ports with type of patch. options : peer: optional string The logical_port in the Port_Binding record for the other side of the patch. The named logical_port must specify this logi‐ cal_port in its own peer option. That is, the two patch logical ports must have reversed logical_port and peer values. nat_addresses: set of strings MAC address followed by a list of SNAT and DNAT external IP ad‐ dresses, followed by is_chassis_resident("lport"), where lport is the name of a logical port on the same chassis where the cor‐ responding NAT rules are applied. This is used to send gratu‐ itous ARPs for SNAT and DNAT external IP addresses via localnet, from the chassis where lport resides. Example: 80:fa:5b:06:72:b7 158.36.44.22 158.36.44.24 is_chassis_resident("foo1"). This would result in generation of gratuitous ARPs for IP addresses 158.36.44.22 and 158.36.44.24 with a MAC address of 80:fa:5b:06:72:b7 from the chassis where the logical port "foo1" resides. L3 Gateway Options: These options apply to logical ports with type of l3gateway. options : peer: optional string The logical_port in the Port_Binding record for the other side of the ’l3gateway’ port. The named logical_port must specify this logical_port in its own peer option. That is, the two ’l3gateway’ logical ports must have reversed logical_port and peer values. options : l3gateway-chassis: optional string The chassis in which the port resides. nat_addresses: set of strings MAC address of the l3gateway port followed by a list of SNAT and DNAT external IP addresses. This is used to send gratuitous ARPs for SNAT and DNAT external IP addresses via localnet. Example: 80:fa:5b:06:72:b7 158.36.44.22 158.36.44.24. This would result in generation of gratuitous ARPs for IP addresses 158.36.44.22 and 158.36.44.24 with a MAC address of 80:fa:5b:06:72:b7. This is used in OVS version 2.8 and later versions. Localnet Options: These options apply to logical ports with type of localnet. options : network_name: optional string Required. ovn-controller uses the configuration entry ovn-bridge-mappings to determine how to connect to this network. ovn-bridge-mappings is a list of network names mapped to a local OVS bridge that provides access to that network. An example of configuring ovn-bridge-mappings would be: .IP $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1 When a logical switch has a localnet port attached, every chas‐ sis that may have a local vif attached to that logical switch must have a bridge mapping configured to reach that localnet. Traffic that arrives on a localnet port is never forwarded over a tunnel to another chassis. If there are multiple localnet ports in a logical switch, each chassis should only have a sin‐ gle bridge mapping for one of the physical networks. Note: In case of multiple localnet ports, to provide interconnectivity between all VIFs located on different chassis with different fabric connectivity, the fabric should implement some form of routing between the segments. tag: optional integer, in range 1 to 4,095 If set, indicates that the port represents a connection to a specific VLAN on a locally accessible network. The VLAN ID is used to match incoming traffic and is also added to outgoing traffic. L2 Gateway Options: These options apply to logical ports with type of l2gateway. options : network_name: optional string Required. ovn-controller uses the configuration entry ovn-bridge-mappings to determine how to connect to this network. ovn-bridge-mappings is a list of network names mapped to a local OVS bridge that provides access to that network. An example of configuring ovn-bridge-mappings would be: .IP $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1 When a logical switch has a l2gateway port attached, the chassis that the l2gateway port is bound to must have a bridge mapping configured to reach the network identified by network_name. options : l2gateway-chassis: optional string Required. The chassis in which the port resides. tag: optional integer, in range 1 to 4,095 If set, indicates that the gateway is connected to a specific VLAN on the physical network. The VLAN ID is used to match in‐ coming traffic and is also added to outgoing traffic. VTEP Options: These options apply to logical ports with type of vtep. options : vtep-physical-switch: optional string Required. The name of the VTEP gateway. options : vtep-logical-switch: optional string Required. A logical switch name connected by the VTEP gateway. Must be set when type is vtep. VMI (or VIF) Options: These options apply to logical ports with type having (empty string) options : requested-chassis: optional string If set, identifies a specific chassis (by name or hostname) that is allowed to bind this port. Using this option will prevent thrashing between two chassis trying to bind the same port dur‐ ing a live migration. It can also prevent similar thrashing due to a mis-configuration, if a port is accidentally created on more than one chassis. options : iface-id-ver: optional string If set, this port will be bound by ovn-controller only if this same key and value is configured in the external_ids column in the Open_vSwitch database’s Interface table. options : qos_min_rate: optional string If set, indicates the minimum guaranteed rate available for data sent from this interface, in bit/s. options : qos_max_rate: optional string If set, indicates the maximum rate for data sent from this in‐ terface, 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. Distributed Gateway Port Options: These options apply to the distributed parent ports of logical ports with type of chasssisredirect. options : chassis-redirect-port: optional string The name of the chassis redirect port derived from this port if this port is a distributed parent of a chassis redirect port. Chassis Redirect Options: These options apply to logical ports with type of chassisredirect. options : distributed-port: optional string The name of the distributed port for which this chassisredirect port represents a particular instance. options : redirect-type: optional string The value is copied from the column options in the OVN_North‐ bound database’s Logical_Router_Port table for the distributed parent of this port. options : always-redirect: optional string A boolean option that is set to true if the distributed parent of this chassis redirect port does not need distributed process‐ ing. Nested Containers: These columns support containers nested within a VM. Specifically, they are used when type is empty and logical_port identifies the interface of a container spawned inside a VM. They are empty for containers or VMs that run directly on a hypervisor. parent_port: optional string This is taken from parent_name in the OVN_Northbound database’s Logical_Switch_Port table. tag: optional integer, in range 1 to 4,095 Identifies the VLAN tag in the network traffic associated with that container’s network interface. This column is used for a different purpose when type is local‐ net (see Localnet Options, above) or l2gateway (see L2 Gateway Options, above). Virtual ports: virtual_parent: optional string This column is set by ovn-controller with one of the value from the options:virtual-parents in the OVN_Northbound database’s Logical_Switch_Port table when the OVN action bind_vport is exe‐ cuted. ovn-controller also sets the chassis column when it exe‐ cutes this action with its chassis id. ovn-controller sets this column only if the type is "virtual". Naming: external_ids : name: optional string For a logical switch port, ovn-northd copies this from exter‐ nal_ids:neutron:port_name in the Logical_Switch_Port table in the OVN_Northbound database, if it is a nonempty string. For a logical switch port, ovn-northd does not currently set this key. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. The ovn-northd program populates this column with all entries into the external_ids column of the Logical_Switch_Port and Log‐ ical_Router_Port tables of the OVN_Northbound database. MAC_Binding TABLE Each row in this table specifies a binding from an IP address to an Ethernet address that has been discovered through ARP (for IPv4) or neighbor discovery (for IPv6). This table is primarily used to discover bindings on physical networks, because IP-to-MAC bindings for virtual machines are usually populated statically into the Port_Binding table. This table expresses a functional relationship: MAC_Binding(logi‐ cal_port, ip) = mac. In outline, the lifetime of a logical router’s MAC binding looks like this: 1. On hypervisor 1, a logical router determines that a packet should be forwarded to IP address A on one of its router ports. It uses its logical flow table to determine that A lacks a static IP-to-MAC binding and the get_arp action to determine that it lacks a dynamic IP-to-MAC binding. 2. Using an OVN logical arp action, the logical router gener‐ ates and sends a broadcast ARP request to the router port. It drops the IP packet. 3. The logical switch attached to the router port delivers the ARP request to all of its ports. (It might make sense to de‐ liver it only to ports that have no static IP-to-MAC bind‐ ings, but this could also be surprising behavior.) 4. A host or VM on hypervisor 2 (which might be the same as hy‐ pervisor 1) attached to the logical switch owns the IP ad‐ dress 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 di‐ rectly 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, domains, host_id, 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, domains, host_id, 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". value: host_id This indicates that the value of the DHCP option is a host_id. It can either be a host_name or an IP address. Example. "name=tftp_server", "code=66", "type=host_id". value: domains This indicates that the value of the DHCP option is a do‐ main name or a comma separated list of domain names. Example. "name=domain_search_list", "code=119", "type=do‐ mains". 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 de‐ fined 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 ap‐ propriate RFC. Example. code=3 type: string, one of ipv6, mac, or str Data type of the DHCPv6 option code. value: ipv6 This indicates that the value of the DHCPv6 option is an IPv6 address(es). Example. "name=ia_addr", "code=5", "type=ipv6". put_dhcpv6_opts(..., ia_addr = ae70::4,...) value: str This indicates that the value of the DHCPv6 option is a string. Example. "name=domain_search", "code=24", "type=str". put_dhcpv6_opts(..., domain_search = ovn.domain,...) value: mac This indicates that the value of the DHCPv6 option is a MAC address. Example. "name=server_id", "code=2", "type=mac". put_dhcpv6_opts(..., server_id = 01:02:03:04L05:06,...) Connection TABLE Configuration for a database connection to an Open vSwitch database (OVSDB) client. This table primarily configures the Open vSwitch database server (ovsdb-server). The Open vSwitch database server can initiate and maintain active con‐ nections to remote clients. It can also listen for database connec‐ tions. Summary: Core Features: target string (must be unique within table) read_only boolean role string Client Failure Detection and Handling: max_backoff optional integer, at least 1,000 inactivity_probe optional integer Status: is_connected boolean status : last_error optional string status : state optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE, or VOID status : sec_since_connect optional string, containing an integer, at least 0 status : sec_since_disconnect optional string, containing an integer, at least 0 status : locks_held optional string status : locks_waiting optional string status : locks_lost optional string status : n_connections optional string, containing an integer, at least 2 status : bound_port optional string, containing an integer Common Columns: external_ids map of string-string pairs other_config map of string-string pairs Details: Core Features: target: string (must be unique within table) Connection methods for clients. The following connection methods are currently supported: ssl:host[:port] The specified SSL port on the given host, which can ei‐ ther be a DNS name (if built with unbound library) or an IP address. A valid SSL configuration must be provided when this form is used, this configuration can be speci‐ fied via command-line options or the SSL table. If port is not specified, it defaults to 6640. SSL support is an optional feature that is not always built as part of Open vSwitch. tcp:host[:port] The specified TCP port on the given host, which can ei‐ ther 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 ad‐ dress, 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) ad‐ dresses. A valid SSL configuration must be provided when this form is used, this can be specified either via com‐ mand-line options or the SSL table. If port is not specified, it defaults to 6640. SSL support is an optional feature that is not always built as part of Open vSwitch. ptcp:[port][:host] Listens for connections on the specified TCP port. Spec‐ ify 0 for port to have the kernel automatically choose an available port. If host, which can either be a DNS name (if built with unbound library) or an IP address, is specified, then connections are restricted to the re‐ solved or specified local IP address (either IPv4 or IPv6 address). If host is an IPv6 address, wrap it in square brackets, e.g. ptcp:6640:[::1]. If host is not specified then it listens only on IPv4 addresses. If port is not specified, it defaults to 6640. When multiple clients are configured, the target values must be unique. Duplicate target values yield unspecified results. read_only: boolean true to restrict these connections to read-only transactions, false to allow them to modify the database. role: string String containing role name for this connection entry. Client Failure Detection and Handling: max_backoff: optional integer, at least 1,000 Maximum number of milliseconds to wait between connection at‐ tempts. Default is implementation-specific. inactivity_probe: optional integer Maximum number of milliseconds of idle time on connection to the client before sending an inactivity probe message. If Open vSwitch does not communicate with the client for the specified number of seconds, it will send a probe. If a response is not received for the same additional amount of time, Open vSwitch assumes the connection has been broken and attempts to recon‐ nect. Default is implementation-specific. A value of 0 disables inactivity probes. Status: Key-value pair of is_connected is always updated. Other key-value pairs in the status columns may be updated depends on the target type. When target specifies a connection method that listens for inbound con‐ nections (e.g. ptcp: or punix:), both n_connections and is_connected may also be updated while the remaining key-value pairs are omitted. On the other hand, when target specifies an outbound connection, all key-value pairs may be updated, except the above-mentioned two key- value pairs associated with inbound connection targets. They are omit‐ ted. is_connected: boolean true if currently connected to this client, false otherwise. status : last_error: optional string A human-readable description of the last error on the connection to the manager; i.e. strerror(errno). This key will exist only if an error has occurred. status : state: optional string, one of ACTIVE, BACKOFF, CONNECTING, IDLE, or VOID The state of the connection to the manager: VOID Connection is disabled. BACKOFF Attempting to reconnect at an increasing period. CONNECTING Attempting to connect. ACTIVE Connected, remote host responsive. IDLE Connection is idle. Waiting for response to keep-alive. These values may change in the future. They are provided only for human consumption. status : sec_since_connect: optional string, containing an integer, at least 0 The amount of time since this client last successfully connected to the database (in seconds). Value is empty if client has never successfully been connected. status : sec_since_disconnect: optional string, containing an integer, at least 0 The amount of time since this client last disconnected from the database (in seconds). Value is empty if client has never dis‐ connected. status : locks_held: optional string Space-separated list of the names of OVSDB locks that the con‐ nection holds. Omitted if the connection does not hold any locks. status : locks_waiting: optional string Space-separated list of the names of OVSDB locks that the con‐ nection is currently waiting to acquire. Omitted if the connec‐ tion is not waiting for any locks. status : locks_lost: optional string Space-separated list of the names of OVSDB locks that the con‐ nection has had stolen by another OVSDB client. Omitted if no locks have been stolen from this connection. status : n_connections: optional string, containing an integer, at least 2 When target specifies a connection method that listens for in‐ bound connections (e.g. ptcp: or pssl:) and more than one con‐ nection is actually active, the value is the number of active connections. Otherwise, this key-value pair is omitted. status : bound_port: optional string, containing an integer When target is ptcp: or pssl:, this is the TCP port on which the OVSDB server is listening. (This is particularly useful when target specifies a port of 0, allowing the kernel to choose any available port.) Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs other_config: map of string-string pairs SSL TABLE SSL configuration for ovn-sb database access. Summary: private_key string certificate string ca_cert string bootstrap_ca_cert boolean ssl_protocols string ssl_ciphers string Common Columns: external_ids map of string-string pairs Details: private_key: string Name of a PEM file containing the private key used as the switch’s identity for SSL connections to the controller. certificate: string Name of a PEM file containing a certificate, signed by the cer‐ tificate authority (CA) used by the controller and manager, that certifies the switch’s private key, identifying a trustworthy switch. ca_cert: string Name of a PEM file containing the CA certificate used to verify that the switch is connected to a trustworthy controller. bootstrap_ca_cert: boolean If set to true, then Open vSwitch will attempt to obtain the CA certificate from the controller on its first SSL connection and save it to the named PEM file. If it is successful, it will im‐ mediately drop the connection and reconnect, and from then on all SSL connections must be authenticated by a certificate signed by the CA certificate thus obtained. This option exposes the SSL connection to a man-in-the-middle attack obtaining the initial CA certificate. It may still be useful for bootstrap‐ ping. ssl_protocols: string List of SSL protocols to be enabled for SSL connections. The de‐ fault when this option is omitted is TLSv1,TLSv1.1,TLSv1.2. ssl_ciphers: string List of ciphers (in OpenSSL cipher string format) to be sup‐ ported for SSL connections. The default when this option is omitted is HIGH:!aNULL:!MD5. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs DNS TABLE Each row in this table stores the DNS records. The OVN action dns_lookup uses this table for DNS resolution. Summary: records map of string-string pairs datapaths set of 1 or more Datapath_Bindings Common Columns: external_ids map of string-string pairs Details: records: map of string-string pairs Key-value pair of DNS records with DNS query name as the key and a string of IP address(es) separated by comma or space as the value. ovn-northd stores the DNS query name in all lowercase in order to facilitate case-insensitive lookups. Example: "vm1.ovn.org" = "10.0.0.4 aef0::4" datapaths: set of 1 or more Datapath_Bindings The DNS records defined in the column records will be applied only to the DNS queries originating from the datapaths defined in this column. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. RBAC_Role TABLE Role table for role-based access controls. Summary: name string permissions map of string-weak reference to RBAC_Per‐ mission pairs Details: name: string The role name, corresponding to the role column in the Connec‐ tion table. permissions: map of string-weak reference to RBAC_Permission pairs A mapping of table names to rows in the RBAC_Permission table. RBAC_Permission TABLE Permissions table for role-based access controls. Summary: table string authorization set of strings insert_delete boolean update set of strings Details: table: string Name of table to which this row applies. authorization: set of strings Set of strings identifying columns and column:key pairs to be compared with client ID. At least one match is required in order to be authorized. A zero-length string is treated as a special value indicating all clients should be considered authorized. insert_delete: boolean When "true", row insertions and authorized row deletions are permitted. update: set of strings Set of strings identifying columns and column:key pairs that au‐ thorized clients are allowed to modify. Gateway_Chassis TABLE Association of Port_Binding rows of type chassisredirect to a Chassis. The traffic going out through a specific chassisredirect port will be redirected to a chassis, or a set of them in high availability configu‐ rations. Summary: name string (must be unique within table) chassis optional weak reference to Chassis priority integer, in range 0 to 32,767 options map of string-string pairs Common Columns: external_ids map of string-string pairs Details: name: string (must be unique within table) Name of the Gateway_Chassis. A suggested, but not required naming convention is ${port_name}_${chassis_name}. chassis: optional weak reference to Chassis The Chassis to which we send the traffic. priority: integer, in range 0 to 32,767 This is the priority the specific Chassis among all Gate‐ way_Chassis belonging to the same Port_Binding. options: map of string-string pairs Reserved for future use. Common Columns: The overall purpose of these columns is described under Common Columns at the beginning of this document. external_ids: map of string-string pairs HA_Chassis TABLE Summary: chassis optional weak reference to Chassis priority integer, in range 0 to 32,767 Common Columns: external_ids map of string-string pairs Details: chassis: optional weak reference to Chassis The Chassis which provides the HA functionality. priority: integer, in range 0 to 32,767 Priority of the HA chassis. Chassis with highest priority will be the master in the HA chassis group. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. HA_Chassis_Group TABLE Table representing a group of chassis which can provide High availabil‐ ity services. Each chassis in the group is represented by the table HA_Chassis. The HA chassis with highest priority will be the master of this group. If the master chassis failover is detected, the HA chassis with the next higher priority takes over the responsibility of provid‐ ing the HA. If ha_chassis_group column of the table Port_Binding refer‐ ences this table, then this HA chassis group provides the gateway func‐ tionality and redirects the gateway traffic to the master of this group. Summary: name string (must be unique within table) ha_chassis set of HA_Chassises ref_chassis set of weak reference to Chassis Common Columns: external_ids map of string-string pairs Details: name: string (must be unique within table) Name of the HA_Chassis_Group. Name should be unique. ha_chassis: set of HA_Chassises A list of HA_Chassis which belongs to this group. ref_chassis: set of weak reference to Chassis The set of Chassis that reference this HA chassis group. To de‐ termine the correct Chassis, find the chassisredirect type Port_Binding that references this HA_Chassis_Group. This Port_Binding is derived from some particular logical router. Starting from that LR, find the set of all logical switches and routers connected to it, directly or indirectly, across router ports that link one LRP to another or to a LSP. For each LSP in these logical switches, find the corresponding Port_Binding and add its bound Chassis (if any) to ref_chassis. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. Controller_Event TABLE Database table used by ovn-controller to report CMS related events. Please note there is no guarantee a given event is written exactly once in the db. It is CMS responsibility to squash duplicated lines or to filter out duplicated events Summary: event_type string, must be empty_lb_backends event_info map of string-string pairs chassis optional weak reference to Chassis seq_num integer Details: event_type: string, must be empty_lb_backends Event type occurred event_info: map of string-string pairs Key-value pairs used to specify event info to the CMS. Possible values are: • vip: VIP reported for the empty_lb_backends event • protocol: Transport protocol reported for the empty_lb_backends event • load_balancer: UUID of the load balancer reported for the empty_lb_backends event chassis: optional weak reference to Chassis This column is a Chassis record to identify the chassis that has managed a given event. seq_num: integer Event sequence number. Global counter for controller generated events. It can be used by the CMS to detect possible duplication of the same event. IP_Multicast TABLE IP Multicast configuration options. For now only applicable to IGMP. Summary: datapath weak reference to Datapath_Binding (must be unique within table) enabled optional boolean querier optional boolean table_size optional integer idle_timeout optional integer query_interval optional integer seq_no integer Querier configuration options: eth_src string ip4_src string ip6_src string query_max_resp optional integer Details: datapath: weak reference to Datapath_Binding (must be unique within ta‐ ble) Datapath_Binding entry for which these configuration options are defined. enabled: optional boolean Enables/disables multicast snooping. Default: disabled. querier: optional boolean Enables/disables multicast querying. If enabled then multicast querying is enabled by default. table_size: optional integer Limits the number of multicast groups that can be learned. De‐ fault: 2048 groups per datapath. idle_timeout: optional integer Configures the idle timeout (in seconds) for IP multicast groups if multicast snooping is enabled. Default: 300 seconds. query_interval: optional integer Configures the interval (in seconds) for sending multicast queries if snooping and querier are enabled. Default: idle_time‐ out/2 seconds. seq_no: integer ovn-controller reads this value and flushes all learned multi‐ cast groups when it detects that seq_no was changed. Querier configuration options: The ovn-controller process that runs on OVN hypervisor nodes uses the following columns to determine field values in IGMP/MLD queries that it originates: eth_src: string Source Ethernet address. ip4_src: string Source IPv4 address. ip6_src: string Source IPv6 address. query_max_resp: optional integer Value (in seconds) to be used as "max-response" field in multi‐ cast queries. Default: 1 second. IGMP_Group TABLE Contains learned IGMP groups indexed by address/datapath/chassis. Summary: address string datapath optional weak reference to Datapath_Bind‐ ing chassis optional weak reference to Chassis ports set of weak reference to Port_Bindings Details: address: string Destination IPv4 address for the IGMP group. datapath: optional weak reference to Datapath_Binding Datapath to which this IGMP group belongs. chassis: optional weak reference to Chassis Chassis to which this IGMP group belongs. ports: set of weak reference to Port_Bindings The destination port bindings for this IGMP group. Service_Monitor TABLE Each row in this table configures monitoring a service for its live‐ ness. The service can be an IPv4 TCP or UDP service. ovn-controller pe‐ riodically sends out service monitor packets and updates the status of the service. Service monitoring for IPv6 services is not supported. ovn-northd uses this feature to implement the load balancer health check feature offered to the CMS through the northbound database. Summary: Configuration: ip string protocol optional string, either tcp or udp port integer, in range 0 to 65,535 logical_port string src_mac string src_ip string options : interval optional string, containing an integer options : timeout optional string, containing an integer options : success_count optional string, containing an integer options : failure_count optional string, containing an integer Status Reporting: status optional string, one of error, offline, or online Common Columns: external_ids map of string-string pairs Details: Configuration: ovn-northd sets these columns and values to configure the service moni‐ tor. ip: string IP of the service to be monitored. Only IPv4 is supported. protocol: optional string, either tcp or udp The protocol of the service. port: integer, in range 0 to 65,535 The TCP or UDP port of the service. logical_port: string The VIF of the logical port on which the service is running. The ovn-controller that binds this logical_port monitors the service by sending periodic monitor packets. src_mac: string Source Ethernet address to use in the service monitor packet. src_ip: string Source IPv4 address to use in the service monitor packet. options : interval: optional string, containing an integer The interval, in seconds, between service monitor checks. options : timeout: optional string, containing an integer The time, in seconds, after which the service monitor check times out. options : success_count: optional string, containing an integer The number of successful checks after which the service is con‐ sidered online. options : failure_count: optional string, containing an integer The number of failure checks after which the service is consid‐ ered offline. Status Reporting: The ovn-controller on the chassis that hosts the logical_port updates this column to report the service’s status. status: optional string, one of error, offline, or online For TCP service, ovn-controller sends a SYN to the service and expects an ACK response to consider the service to be online. For UDP service, ovn-controller sends a UDP packet to the ser‐ vice and doesn’t expect any reply. If it receives an ICMP reply, then it considers the service to be offline. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. Load_Balancer TABLE Each row represents a load balancer. Summary: name string vips map of string-string pairs protocol optional string, one of sctp, tcp, or udp datapaths set of Datapath_Bindings Load_Balancer options: options : hairpin_snat_ip optional string options : hairpin_orig_tuple optional string, either true or false Common Columns: external_ids map of string-string pairs Details: name: string A name for the load balancer. This name has no special meaning or purpose other than to provide convenience for human interac‐ tion with the ovn-nb database. vips: map of string-string pairs A map of virtual IP addresses (and an optional port number with : as a separator) associated with this load balancer and their corresponding endpoint IP addresses (and optional port numbers with : as separators) separated by commas. protocol: optional string, one of sctp, tcp, or udp Valid protocols are tcp, udp, or sctp. This column is useful when a port number is provided as part of the vips column. If this column is empty and a port number is provided as part of vips column, OVN assumes the protocol to be tcp. datapaths: set of Datapath_Bindings Datapaths to which this load balancer applies to. Load_Balancer options: options : hairpin_snat_ip: optional string IP to be used as source IP for packets that have been hair- pinned after load balancing. This value is automatically popu‐ lated by ovn-northd. options : hairpin_orig_tuple: optional string, either true or false This value is automatically set to true by ovn-northd when orig‐ inal destination IP and transport port of the load balanced packets are stored in registers reg1, reg2, xxreg1. Common Columns: external_ids: map of string-string pairs See External IDs at the beginning of this document. BFD TABLE Contains BFD parameter for ovn-controller bfd configuration. Summary: Configuration: src_port integer, in range 49,152 to 65,535 disc integer logical_port string dst_ip string min_tx integer min_rx integer detect_mult integer options map of string-string pairs external_ids map of string-string pairs Status Reporting: status string, one of admin_down, down, init, or up Details: Configuration: src_port: integer, in range 49,152 to 65,535 udp source port used in bfd control packets. The source port MUST be in the range 49152 through 65535 (RFC5881 section 4). disc: integer A unique, nonzero discriminator value generated by the transmit‐ ting system, used to demultiplex multiple BFD sessions between the same pair of systems. logical_port: string OVN logical port when BFD engine is running. dst_ip: string BFD peer IP address. min_tx: integer This is the minimum interval, in milliseconds, that the local system would like to use when transmitting BFD Control packets, less any jitter applied. The value zero is reserved. min_rx: integer This is the minimum interval, in milliseconds, between received BFD Control packets that this system is capable of supporting, less any jitter applied by the sender. If this value is zero, the transmitting system does not want the remote system to send any periodic BFD Control packets. detect_mult: integer Detection time multiplier. The negotiated transmit interval, multiplied by this value, provides the Detection Time for the receiving system in Asynchronous mode. options: map of string-string pairs Reserved for future use. external_ids: map of string-string pairs See External IDs at the beginning of this document. Status Reporting: status: string, one of admin_down, down, init, or up BFD port logical states. Possible values are: • admin_down • down • init • up FDB TABLE This table is primarily used to learn the MACs observed on a VIF which belongs to a Logical_Switch_Port record in OVN_Northbound whose port security is disabled and ’unknown’ address set. If port security is disabled on a Logical_Switch_Port record, OVN should allow traffic with any source mac from the VIF. This table will be used to deliver a packet to the VIF, If a packet’s eth.dst is learnt. Summary: mac string dp_key integer, in range 1 to 16,777,215 port_key integer, in range 1 to 16,777,215 Details: mac: string The learnt mac address. dp_key: integer, in range 1 to 16,777,215 The key of the datapath on which this FDB was learnt. port_key: integer, in range 1 to 16,777,215 The key of the port binding on which this FDB was learnt. Open vSwitch 22.03.8 DB Schema 20.21.0 ovn-sb(5)