man Open_vSwitch (5): Open_vSwitch database schema

Common Columns

Most tables contain two special columns, named other_config and external_ids. These columns have the same form and purpose each place that they appear, so we describe them here to save space later.

other_config: map of string-string pairs: Key-value pairs for configuring rarely used features. Supported keys, along with the forms taken by their values, are documented individually for each table.
: A few tables do not have other_config columns because no key-value pairs have yet been defined for them.
external_ids: map of string-string pairs: Key-value pairs for use by external frameworks that integrate with Open vSwitch, rather than by Open vSwitch itself. System integrators should either use the Open vSwitch development mailing list to coordinate on common key-value definitions, or choose key names that are likely to be unique. In some cases, where key-value pairs have been defined that are likely to be widely useful, they are documented individually for each table.

TABLE SUMMARY

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

Table: Purpose
Open_vSwitch: Open vSwitch configuration.
Bridge: Bridge configuration.
Port: Port configuration.
Interface: One physical network device in a Port.
QoS: Quality of Service configuration
Queue: QoS output queue.
Mirror: Port mirroring.
Controller: OpenFlow controller configuration.
Manager: OVSDB management connection.
NetFlow: NetFlow configuration.
SSL: SSL configuration.
sFlow: sFlow configuration.
Capability: Capability configuration.

Open_vSwitch TABLE

Configuration for an Open vSwitch daemon. There must be exactly one record in the Open_vSwitch table.

Summary:

Configuration:
Status:
Version Reporting:
Database Configuration:
Common Columns:

Details:

Configuration:

bridges: set of Bridges: Set of bridges managed by the daemon.
ssl: optional SSL: SSL used globally by the daemon.
external_ids : system-id: optional string: A unique identifier for the Open vSwitch's physical host. The form of the identifier depends on the type of the host. On a Citrix XenServer, this will likely be the same as external_ids:xs-system-uuid.
external_ids : xs-system-uuid: optional string: The Citrix XenServer universally unique identifier for the physical host as displayed by xe host-list.

Status:

next_cfg: integer: Sequence number for client to increment. When a client modifies any part of the database configuration and wishes to wait for Open vSwitch to finish applying the changes, it may increment this sequence number.
cur_cfg: integer: Sequence number that Open vSwitch sets to the current value of next_cfg after it finishes applying a set of configuration changes.
capabilities: map of string-Capability pairs: Describes functionality supported by the hardware and software platform on which this Open vSwitch is based. Clients should not modify this column. See the Capability description for defined capability categories and the meaning of associated Capability records.

Statistics: The statistics column contains key-value pairs that report statistics about a system running an Open vSwitch. These are updated periodically (currently, every 5 seconds). Key-value pairs that cannot be determined or that do not apply to a platform are omitted.

other_config : enable-statistics: optional string, either true or false

Statistics are disabled by default to avoid overhead in the common case when statistics gathering is not useful. Set this value to true to enable populating the statistics column or to false to explicitly disable it.

statistics : cpu: optional string, containing an integer, at least 1

Number of CPU processors, threads, or cores currently online and available to the operating system on which Open vSwitch is running, as an integer. This may be less than the number installed, if some are not online or if they are not available to the operating system.

Open vSwitch userspace processes are not multithreaded, but the Linux kernel-based datapath is.

statistics : load_average: optional string

A comma-separated list of three floating-point numbers, representing the system load average over the last 1, 5, and 15 minutes, respectively.

statistics : memory: optional string

A comma-separated list of integers, each of which represents a quantity of memory in kilobytes that describes the operating system on which Open vSwitch is running. In respective order, these values are:

1.: Total amount of RAM allocated to the OS.
2.: RAM allocated to the OS that is in use.
3.: RAM that can be flushed out to disk or otherwise discarded if that space is needed for another purpose. This number is necessarily less than or equal to the previous value.
4.: Total disk space allocated for swap.
5.: Swap space currently in use.

On Linux, all five values can be determined and are included. On other operating systems, only the first two values can be determined, so the list will only have two values.

statistics : process_NAME: optional string

One such key-value pair, with NAME replaced by a process name, will exist for each running Open vSwitch daemon process, with name replaced by the daemon's name (e.g. process_ovs-vswitchd). The value is a comma-separated list of integers. The integers represent the following, with memory measured in kilobytes and durations in milliseconds:

1.: The process's virtual memory size.
2.: The process's resident set size.
3.: The amount of user and system CPU time consumed by the process.
4.: The number of times that the process has crashed and been automatically restarted by the monitor.
5.: The duration since the process was started.
6.: The duration for which the process has been running.

The interpretation of some of these values depends on whether the process was started with the --monitor. If it was not, then the crash count will always be 0 and the two durations will always be the same. If --monitor was given, then the crash count may be positive; if it is, the latter duration is the amount of time since the most recent crash and restart.

There will be one key-value pair for each file in Open vSwitch's ``run directory'' (usually /var/run/openvswitch) whose name ends in .pid, whose contents are a process ID, and which is locked by a running process. The name is taken from the pidfile's name.

Currently Open vSwitch is only able to obtain all of the above detail on Linux systems. On other systems, the same key-value pairs will be present but the values will always be the empty string.

statistics : file_systems: optional string

A space-separated list of information on local, writable file systems. Each item in the list describes one file system and consists in turn of a comma-separated list of the following:

1.: Mount point, e.g. / or /var/log. Any spaces or commas in the mount point are replaced by underscores.
2.: Total size, in kilobytes, as an integer.
3.: Amount of storage in use, in kilobytes, as an integer.

This key-value pair is omitted if there are no local, writable file systems or if Open vSwitch cannot obtain the needed information.

Version Reporting: These columns report the types and versions of the hardware and software running Open vSwitch. We recommend in general that software should test whether specific features are supported instead of relying on version number checks. These values are primarily intended for reporting to human administrators.

ovs_version: optional string: The Open vSwitch version number, e.g. 1.1.0. If Open vSwitch was configured with a build number, then it is also included, e.g. 1.1.0+build6579.
db_version: optional string: The database schema version number in the form major.minor.tweak, e.g. 1.2.3. Whenever the database schema is changed in a non-backward compatible way (e.g. deleting a column or a table), major is incremented. When the database schema is changed in a backward compatible way (e.g. adding a new column), minor is incremented. When the database schema is changed cosmetically (e.g. reindenting its syntax), tweak is incremented.
: The schema version is part of the database schema, so it can also be retrieved by fetching the schema using the Open vSwitch database protocol.
system_type: optional string: An identifier for the type of system on top of which Open vSwitch runs, e.g. XenServer or KVM.
: System integrators are responsible for choosing and setting an appropriate value for this column.
system_version: optional string: The version of the system identified by system_type, e.g. 5.6.100-39265p on XenServer 5.6.100 build 39265.
: System integrators are responsible for choosing and setting an appropriate value for this column.

Database Configuration: These columns primarily configure the Open vSwitch database (ovsdb-server), not the Open vSwitch switch (ovs-vswitchd). The OVSDB database also uses the ssl settings.

The Open vSwitch switch does read the database configuration to determine remote IP addresses to which in-band control should apply.

manager_options: set of Managers: Database clients to which the Open vSwitch database server should connect or to which it should listen, along with options for how these connection should be configured. See the Manager table for more information.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

Bridge TABLE

Configuration for a bridge within an Open_vSwitch.

A Bridge record represents an Ethernet switch with one or more ``ports,'' which are the Port records pointed to by the Bridge's ports column.

Summary:

Core Features:
OpenFlow Configuration:
Spanning Tree Configuration:
Other Features:
Bridge Status:
Common Columns:

Details:

Core Features:

name: string (must be unique within table): Bridge identifier. Should be alphanumeric and no more than about 8 bytes long. Must be unique among the names of ports, interfaces, and bridges on a host.
ports: set of Ports: Ports included in the bridge.
mirrors: set of Mirrors: Port mirroring configuration.
netflow: optional NetFlow: NetFlow configuration.
sflow: optional sFlow: sFlow configuration.
flood_vlans: set of up to 4,096 integers, in range 0 to 4,095: VLAN IDs of VLANs on which MAC address learning should be disabled, so that packets are flooded instead of being sent to specific ports that are believed to contain packets' destination MACs. This should ordinarily be used to disable MAC learning on VLANs used for mirroring (RSPAN VLANs). It may also be useful for debugging.
: SLB bonding (see the bond_mode column in the Port table) is incompatible with flood_vlans. Consider using another bonding mode or a different type of mirror instead.

OpenFlow Configuration:

controller: set of Controllers

OpenFlow controller set. If unset, then no OpenFlow controllers will be used.

fail_mode: optional string, either secure or standalone

When a controller is configured, it is, ordinarily, responsible for setting up all flows on the switch. Thus, if the connection to the controller fails, no new network connections can be set up. If the connection to the controller stays down long enough, no packets can pass through the switch at all. This setting determines the switch's response to such a situation. It may be set to one of the following:

standalone: If no message is received from the controller for three times the inactivity probe interval (see inactivity_probe), then Open vSwitch will take over responsibility for setting up flows. In this mode, Open vSwitch causes the bridge to act like an ordinary MAC-learning switch. Open vSwitch will continue to retry connecting to the controller in the background and, when the connection succeeds, it will discontinue its standalone behavior.
secure: Open vSwitch will not set up flows on its own when the controller connection fails or when no controllers are defined. The bridge will continue to retry connecting to any defined controllers forever.

If this value is unset, the default is implementation-specific.

When more than one controller is configured, fail_mode is considered only when none of the configured controllers can be contacted.

datapath_id: optional string

Reports the OpenFlow datapath ID in use. Exactly 16 hex digits. (Setting this column has no useful effect. Set other-config:datapath-id instead.)

other_config : datapath-id: optional string

Exactly 16 hex digits to set the OpenFlow datapath ID to a specific value. May not be all-zero.

other_config : disable-in-band: optional string, either true or false

If set to true, disable in-band control on the bridge regardless of controller and manager settings.

other_config : in-band-queue: optional string, containing an integer, in range 0 to 4,294,967,295

A queue ID as a nonnegative integer. This sets the OpenFlow queue ID that will be used by flows set up by in-band control on this bridge. If unset, or if the port used by an in-band control flow does not have QoS configured, or if the port does not have a queue with the specified ID, the default queue is used instead.

Spanning Tree Configuration: The IEEE 802.1D Spanning Tree Protocol (STP) is a network protocol that ensures loop-free topologies. It allows redundant links to be included in the network to provide automatic backup paths if the active links fails.

stp_enable: boolean: Enable spanning tree on the bridge. By default, STP is disabled on bridges. Bond, internal, and mirror ports are not supported and will not participate in the spanning tree.
other_config : stp-system-id: optional string: The bridge's STP identifier (the lower 48 bits of the bridge-id) in the form xx:xx:xx:xx:xx:xx. By default, the identifier is the MAC address of the bridge.
other_config : stp-priority: optional string, containing an integer, in range 0 to 65,535: The bridge's relative priority value for determining the root bridge (the upper 16 bits of the bridge-id). A bridge with the lowest bridge-id is elected the root. By default, the priority is 0x8000.
other_config : stp-hello-time: optional string, containing an integer, in range 1 to 10: The interval between transmissions of hello messages by designated ports, in seconds. By default the hello interval is 2 seconds.
other_config : stp-max-age: optional string, containing an integer, in range 6 to 40: The maximum age of the information transmitted by the bridge when it is the root bridge, in seconds. By default, the maximum age is 20 seconds.
other_config : stp-forward-delay: optional string, containing an integer, in range 4 to 30: The delay to wait between transitioning root and designated ports to forwarding, in seconds. By default, the forwarding delay is 15 seconds.

Other Features:

datapath_type: string: Name of datapath provider. The kernel datapath has type system. The userspace datapath has type netdev.
external_ids : bridge-id: optional string: A unique identifier of the bridge. On Citrix XenServer this will commonly be the same as external_ids:xs-network-uuids.
external_ids : xs-network-uuids: optional string: Semicolon-delimited set of universally unique identifier(s) for the network with which this bridge is associated on a Citrix XenServer host. The network identifiers are RFC 4122 UUIDs as displayed by, e.g., xe network-list.
other_config : hwaddr: optional string: An Ethernet address in the form xx:xx:xx:xx:xx:xx to set the hardware address of the local port and influence the datapath ID.
other_config : flow-eviction-threshold: optional string, containing an integer, at least 0: A number of flows as a nonnegative integer. This sets number of flows at which eviction from the kernel flow table will be triggered. If there are a large number of flows then increasing this value to around the number of flows present can result in reduced CPU usage and packet loss.
: The default is 1000. Values below 100 will be rounded up to 100.
other_config : forward-bpdu: optional string, either true or false: Option to allow forwarding of BPDU frames when NORMAL action is invoked. Frames with reserved Ethernet addresses (e.g. STP BPDU) will be forwarded when this option is enabled and the switch is not providing that functionality. If STP is enabled on the port, STP BPDUs will never be forwarded. If the Open vSwitch bridge is used to connect different Ethernet networks, and if Open vSwitch node does not run STP, then this option should be enabled. Default is disabled, set to true to enable.
other_config : mac-aging-time: optional string, containing an integer, at least 1: The maximum number of seconds to retain a MAC learning entry for which no packets have been seen. The default is currently 300 seconds (5 minutes). The value, if specified, is forced into a reasonable range, currently 15 to 3600 seconds.
: A short MAC aging time allows a network to more quickly detect that a host is no longer connected to a switch port. However, it also makes it more likely that packets will be flooded unnecessarily, when they are addressed to a connected host that rarely transmits packets. To reduce the incidence of unnecessary flooding, use a MAC aging time longer than the maximum interval at which a host will ordinarily transmit packets.

Bridge Status: Status information about bridges.

status: map of string-string pairs: Key-value pairs that report bridge status.
status : stp_bridge_id: optional string: The bridge-id (in hex) used in spanning tree advertisements. Configuring the bridge-id is described in the stp-system-id and stp-priority keys of the other_config section earlier.
status : stp_designated_root: optional string: The designated root (in hex) for this spanning tree.
status : stp_root_path_cost: optional string: The path cost of reaching the designated bridge. A lower number is better.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

Port TABLE

A port within a Bridge.

Most commonly, a port has exactly one ``interface,'' pointed to by its interfaces column. Such a port logically corresponds to a port on a physical Ethernet switch. A port with more than one interface is a ``bonded port'' (see Bonding Configuration).

Some properties that one might think as belonging to a port are actually part of the port's Interface members.

Summary:

name: string (must be unique within table)
interfaces: set of 1 or more Interfaces
VLAN Configuration:
Bonding Configuration:
Spanning Tree Configuration:
Other Features:
Port Status:
Port Statistics:
Common Columns:

Details:

name: string (must be unique within table): Port name. Should be alphanumeric and no more than about 8 bytes long. May be the same as the interface name, for non-bonded ports. Must otherwise be unique among the names of ports, interfaces, and bridges on a host.
interfaces: set of 1 or more Interfaces: The port's interfaces. If there is more than one, this is a bonded Port.

VLAN Configuration: Bridge ports support the following types of VLAN configuration:

trunk: A trunk port carries packets on one or more specified VLANs specified in the trunks column (often, on every VLAN). A packet that ingresses on a trunk port is in the VLAN specified in its 802.1Q header, or VLAN 0 if the packet has no 802.1Q header. A packet that egresses through a trunk port will have an 802.1Q header if it has a nonzero VLAN ID.
: Any packet that ingresses on a trunk port tagged with a VLAN that the port does not trunk is dropped.
access: An access port carries packets on exactly one VLAN specified in the tag column. Packets egressing on an access port have no 802.1Q header.
: Any packet with an 802.1Q header with a nonzero VLAN ID that ingresses on an access port is dropped, regardless of whether the VLAN ID in the header is the access port's VLAN ID.
native-tagged: A native-tagged port resembles a trunk port, with the exception that a packet without an 802.1Q header that ingresses on a native-tagged port is in the ``native VLAN'' (specified in the tag column).
native-untagged: A native-untagged port resembles a native-tagged port, with the exception that a packet that egresses on a native-untagged port in the native VLAN will not have an 802.1Q header.

A packet will only egress through bridge ports that carry the VLAN of the packet, as described by the rules above.

vlan_mode: optional string, one of access, native-tagged, native-untagged, or trunk

The VLAN mode of the port, as described above. When this column is empty, a default mode is selected as follows:

If tag contains a value, the port is an access port. The trunks column should be empty.
Otherwise, the port is a trunk port. The trunks column value is honored if it is present.

tag: optional integer, in range 0 to 4,095

For an access port, the port's implicitly tagged VLAN. For a native-tagged or native-untagged port, the port's native VLAN. Must be empty if this is a trunk port.

trunks: set of up to 4,096 integers, in range 0 to 4,095

For a trunk, native-tagged, or native-untagged port, the 802.1Q VLAN or VLANs that this port trunks; if it is empty, then the port trunks all VLANs. Must be empty if this is an access port.

A native-tagged or native-untagged port always trunks its native VLAN, regardless of whether trunks includes that VLAN.

other_config : priority-tags: optional string, either true or false

An 802.1Q header contains two important pieces of information: a VLAN ID and a priority. A frame with a zero VLAN ID, called a ``priority-tagged'' frame, is supposed to be treated the same way as a frame without an 802.1Q header at all (except for the priority).

However, some network elements ignore any frame that has 802.1Q header at all, even when the VLAN ID is zero. Therefore, by default Open vSwitch does not output priority-tagged frames, instead omitting the 802.1Q header entirely if the VLAN ID is zero. Set this key to true to enable priority-tagged frames on a port.

Regardless of this setting, Open vSwitch omits the 802.1Q header on output if both the VLAN ID and priority would be zero.

All frames output to native-tagged ports have a nonzero VLAN ID, so this setting is not meaningful on native-tagged ports.

Bonding Configuration: A port that has more than one interface is a ``bonded port.'' Bonding allows for load balancing and fail-over. Some kinds of bonding will work with any kind of upstream switch:

balance-slb: Balances flows among slaves based on source MAC address and output VLAN, with periodic rebalancing as traffic patterns change.
active-backup: Assigns all flows to one slave, failing over to a backup slave when the active slave is disabled.

The following modes require the upstream switch to support 802.3ad with successful LACP negotiation. If LACP negotiation fails then balance-slb style flow hashing is used as a fallback:

balance-tcp: Balances flows among slaves based on L2, L3, and L4 protocol information such as destination MAC address, IP address, and TCP port.
stable: Attempts to always assign a given flow to the same slave consistently. In an effort to maintain stability, no load balancing is done. Uses a similar hashing strategy to balance-tcp, always taking into account L3 and L4 fields even if LACP negotiations are unsuccessful.
: Slave selection decisions are made based on other_config:bond-stable-id if set. Otherwise, OpenFlow port number is used. Decisions are consistent across all ovs-vswitchd instances with equivalent other_config:bond-stable-id values.

These columns apply only to bonded ports. Their values are otherwise ignored.

bond_mode: optional string, one of active-backup, balance-tcp, balance-slb, or stable: The type of bonding used for a bonded port. Defaults to balance-slb if unset.

Link Failure Detection: An important part of link bonding is detecting that links are down so that they may be disabled. These settings determine how Open vSwitch detects link failure.

other_config : bond-detect-mode: optional string, either miimon or carrier: The means used to detect link failures. Defaults to carrier which uses each interface's carrier to detect failures. When set to miimon, will check for failures by polling each interface's MII.
other_config : bond-miimon-interval: optional string, containing an integer: The interval, in milliseconds, between successive attempts to poll each interface's MII. Relevant only when other_config:bond-detect-mode is miimon.
bond_updelay: integer: The number of milliseconds for which carrier must stay up on an interface before the interface is considered to be up. Specify 0 to enable the interface immediately.
: This setting is honored only when at least one bonded interface is already enabled. When no interfaces are enabled, then the first bond interface to come up is enabled immediately.
bond_downdelay: integer: The number of milliseconds for which carrier must stay down on an interface before the interface is considered to be down. Specify 0 to disable the interface immediately.

LACP Configuration: LACP, the Link Aggregation Control Protocol, is an IEEE standard that allows switches to automatically detect that they are connected by multiple links and aggregate across those links. These settings control LACP behavior.

lacp: optional string, one of active, passive, or off: Configures LACP on this port. LACP allows directly connected switches to negotiate which links may be bonded. LACP may be enabled on non-bonded ports for the benefit of any switches they may be connected to. active ports are allowed to initiate LACP negotiations. passive ports are allowed to participate in LACP negotiations initiated by a remote switch, but not allowed to initiate such negotiations themselves. Defaults to off if unset.
other_config : lacp-system-id: optional string: The LACP system ID of this Port. The system ID of a LACP bond is used to identify itself to its partners. Must be a nonzero MAC address.
other_config : lacp-system-priority: optional string, containing an integer, in range 1 to 65,535: The LACP system priority of this Port. In LACP negotiations, link status decisions are made by the system with the numerically lower priority.
other_config : lacp-time: optional string: The LACP timing which should be used on this Port. Possible values are fast, slow and a positive number of milliseconds. By default slow is used. When configured to be fast LACP heartbeats are requested at a rate of once per second causing connectivity problems to be detected more quickly. In slow mode, heartbeats are requested at a rate of once every 30 seconds.
: Users may manually set a heartbeat transmission rate to increase the fault detection speed further. When manually set, OVS expects the partner switch to be configured with the same transmission rate. Manually setting lacp-time to something other than fast or slow is not supported by the LACP specification.
other_config : lacp-heartbeat: optional string, either true or false: Treat LACP like a simple heartbeat protocol for link state monitoring. Most features of the LACP protocol are disabled when this mode is in use. The default if not specified is false.
other_config : bond-hash-basis: optional string, containing an integer: An integer hashed along with flows when choosing output slaves. When changed, all flows will be assigned different hash values possibly causing slave selection decisions to change.

SLB Configuration: These settings control behavior when a bond is in balance-slb mode, regardless of whether the bond was intentionally configured in SLB mode or it fell back to SLB mode because LACP negotiation failed.

other_config : bond-rebalance-interval: optional string, containing an integer, in range 1,000 to 10,000: For an SLB bonded port, the number of milliseconds between successive attempts to rebalance the bond, that is, to move source MACs and their flows from one interface on the bond to another in an attempt to keep usage of each interface roughly equal.
bond_fake_iface: boolean: For a bonded port, whether to create a fake internal interface with the name of the port. Use only for compatibility with legacy software that requires this.

Spanning Tree Configuration:

other_config : stp-enable: optional string, either true or false: If spanning tree is enabled on the bridge, member ports are enabled by default (with the exception of bond, internal, and mirror ports which do not work with STP). If this column's value is false spanning tree is disabled on the port.
other_config : stp-port-num: optional string, containing an integer, in range 1 to 255: The port number used for the lower 8 bits of the port-id. By default, the numbers will be assigned automatically. If any port's number is manually configured on a bridge, then they must all be.
other_config : stp-port-priority: optional string, containing an integer, in range 0 to 255: The port's relative priority value for determining the root port (the upper 8 bits of the port-id). A port with a lower port-id will be chosen as the root port. By default, the priority is 0x80.
other_config : stp-path-cost: optional string, containing an integer, in range 0 to 65,535: Spanning tree path cost for the port. A lower number indicates a faster link. By default, the cost is based on the maximum speed of the link.

Other Features:

qos: optional QoS: Quality of Service configuration for this port.
mac: optional string: The MAC address to use for this port for the purpose of choosing the bridge's MAC address. This column does not necessarily reflect the port's actual MAC address, nor will setting it change the port's actual MAC address.
fake_bridge: boolean: Does this port represent a sub-bridge for its tagged VLAN within the Bridge? See ovs-vsctl(8) for more information.
external_ids : fake-bridge-id-*: optional string: External IDs for a fake bridge (see the fake_bridge column) are defined by prefixing a Bridge external_ids key with fake-bridge-, e.g. fake-bridge-xs-network-uuids.

Port Status: Status information about ports attached to bridges.

status: map of string-string pairs: Key-value pairs that report port status.
status : stp_port_id: optional string: The port-id (in hex) used in spanning tree advertisements for this port. Configuring the port-id is described in the stp-port-num and stp-port-priority keys of the other_config section earlier.
status : stp_state: optional string, one of disabled, forwarding, learning, listening, or blocking: STP state of the port.
status : stp_sec_in_state: optional string, containing an integer, at least 0: The amount of time (in seconds) port has been in the current STP state.
status : stp_role: optional string, one of designated, alternate, or root: STP role of the port.

Port Statistics: Key-value pairs that report port statistics.

Statistics: STP transmit and receive counters:

statistics : stp_tx_count: optional integer: Number of STP BPDUs sent on this port by the spanning tree library.
statistics : stp_rx_count: optional integer: Number of STP BPDUs received on this port and accepted by the spanning tree library.
statistics : stp_error_count: optional integer: Number of bad STP BPDUs received on this port. Bad BPDUs include runt packets and those with an unexpected protocol ID.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

Interface TABLE

An interface within a Port.

Summary:

Core Features:
System-Specific Details:
Tunnel Options:
Patch Options:
Interface Status:
Statistics:
Ingress Policing:
Connectivity Fault Management:
Bonding Configuration:
Virtual Machine Identifiers:
VLAN Splinters:
Common Columns:

Details:

Core Features:

name: string (must be unique within table)

Interface name. Should be alphanumeric and no more than about 8 bytes long. May be the same as the port name, for non-bonded ports. Must otherwise be unique among the names of ports, interfaces, and bridges on a host.

mac: optional string

Ethernet address to set for this interface. If unset then the default MAC address is used:

For the local interface, the default is the lowest-numbered MAC address among the other bridge ports, either the value of the mac in its Port record, if set, or its actual MAC (for bonded ports, the MAC of its slave whose name is first in alphabetical order). Internal ports and bridge ports that are used as port mirroring destinations (see the Mirror table) are ignored.
For other internal interfaces, the default MAC is randomly generated.
External interfaces typically have a MAC address associated with their hardware.

Some interfaces may not have a software-controllable MAC address.

ofport: optional integer

OpenFlow port number for this interface. Unlike most columns, this column's value should be set only by Open vSwitch itself. Other clients should set this column to an empty set (the default) when creating an Interface.

Open vSwitch populates this column when the port number becomes known. If the interface is successfully added, ofport will be set to a number between 1 and 65535 (generally either in the range 1 to 65279, inclusive, or 65534, the port number for the OpenFlow ``local port''). If the interface cannot be added then Open vSwitch sets this column to -1.

System-Specific Details:

type: string

The interface type, one of:

system: An ordinary network device, e.g. eth0 on Linux. Sometimes referred to as ``external interfaces'' since they are generally connected to hardware external to that on which the Open vSwitch is running. The empty string is a synonym for system.
internal: A simulated network device that sends and receives traffic. An internal interface whose name is the same as its bridge's name is called the ``local interface.'' It does not make sense to bond an internal interface, so the terms ``port'' and ``interface'' are often used imprecisely for internal interfaces.
tap: A TUN/TAP device managed by Open vSwitch.
gre: An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4 tunnel. See Tunnel Options for information on configuring GRE tunnels.
ipsec_gre: An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4 IPsec tunnel.
capwap: An Ethernet tunnel over the UDP transport portion of CAPWAP (RFC 5415). This allows interoperability with certain switches that do not support GRE. Only the tunneling component of the protocol is implemented. UDP ports 58881 and 58882 are used as the source and destination ports respectively. CAPWAP is currently supported only with the Linux kernel datapath with kernel version 2.6.26 or later.
patch: A pair of virtual devices that act as a patch cable.
null: An ignored interface.

Tunnel Options: These options apply to interfaces with type of gre, ipsec_gre, and capwap.

Each tunnel must be uniquely identified by the combination of type, options:remote_ip, options:local_ip, and options:in_key. If two ports are defined that are the same except one has an optional identifier and the other does not, the more specific one is matched first. options:in_key is considered more specific than options:local_ip if a port defines one and another port defines the other.

options : remote_ip: optional string

Required. The tunnel endpoint. Unicast and multicast endpoints are both supported.

When a multicast endpoint is specified, a routing table lookup occurs only when the tunnel is created. Following a routing change, delete and then re-create the tunnel to force a new routing table lookup.

options : local_ip: optional string

Optional. The destination IP that received packets must match. Default is to match all addresses. Must be omitted when options:remote_ip is a multicast address.

options : in_key: optional string

Optional. The key that received packets must contain, one of:

0. The tunnel receives packets with no key or with a key of 0. This is equivalent to specifying no options:in_key at all.
A positive 32-bit (for GRE) or 64-bit (for CAPWAP) number. The tunnel receives only packets with the specified key.
The word flow. The tunnel accepts packets with any key. The key will be placed in the tun_id field for matching in the flow table. The ovs-ofctl manual page contains additional information about matching fields in OpenFlow flows.

options : out_key: optional string

Optional. The key to be set on outgoing packets, one of:

0. Packets sent through the tunnel will have no key. This is equivalent to specifying no options:out_key at all.
A positive 32-bit (for GRE) or 64-bit (for CAPWAP) number. Packets sent through the tunnel will have the specified key.
The word flow. Packets sent through the tunnel will have the key set using the set_tunnel Nicira OpenFlow vendor extension (0 is used in the absence of an action). The ovs-ofctl manual page contains additional information about the Nicira OpenFlow vendor extensions.

options : key: optional string

Optional. Shorthand to set in_key and out_key at the same time.

options : tos: optional string

Optional. The value of the ToS bits to be set on the encapsulating packet. It may also be the word inherit, in which case the ToS will be copied from the inner packet if it is IPv4 or IPv6 (otherwise it will be 0). The ECN fields are always inherited. Default is 0.

options : ttl: optional string

Optional. The TTL to be set on the encapsulating packet. It may also be the word inherit, in which case the TTL will be copied from the inner packet if it is IPv4 or IPv6 (otherwise it will be the system default, typically 64). Default is the system default TTL.

options : df_inherit: optional string, either true or false

Optional. If enabled, the Don't Fragment bit will be copied from the inner IP headers (those of the encapsulated traffic) to the outer (tunnel) headers. Default is disabled; set to true to enable.

options : df_default: optional string, either true or false

Optional. If enabled, the Don't Fragment bit will be set by default on tunnel headers if the df_inherit option is not set, or if the encapsulated packet is not IP. Default is enabled; set to false to disable.

options : pmtud: optional string, either true or false

Optional. Enable tunnel path MTU discovery. If enabled ``ICMP Destination Unreachable - Fragmentation Needed'' messages will be generated for IPv4 packets with the DF bit set and IPv6 packets above the minimum MTU if the packet size exceeds the path MTU minus the size of the tunnel headers. Note that this option causes behavior that is typically reserved for routers and therefore is not entirely in compliance with the IEEE 802.1D specification for bridges. Default is enabled; set to false to disable.

Tunnel Options: gre only: Only gre interfaces support these options.

options : header_cache: optional string, either true or false: Enable caching of tunnel headers and the output path. This can lead to a significant performance increase without changing behavior. In general it should not be necessary to adjust this setting. However, the caching can bypass certain components of the IP stack (such as iptables) and it may be useful to disable it if these features are required or as a debugging measure. Default is enabled, set to false to disable.

Tunnel Options: gre and ipsec_gre only: Only gre and ipsec_gre interfaces support these options.

options : csum: optional string, either true or false: Optional. Compute GRE checksums on outgoing packets. Default is disabled, set to true to enable. Checksums present on incoming packets will be validated regardless of this setting.
: GRE checksums impose a significant performance penalty because they cover the entire packet. The encapsulated L3, L4, and L7 packet contents typically have their own checksums, so this additional checksum only adds value for the GRE and encapsulated L2 headers.
: This option is supported for ipsec_gre, but not useful because GRE checksums are weaker than, and redundant with, IPsec payload authentication.

Tunnel Options: ipsec_gre only: Only ipsec_gre interfaces support these options.

options : peer_cert: optional string: Required for certificate authentication. A string containing the peer's certificate in PEM format. Additionally the host's certificate must be specified with the certificate option.
options : certificate: optional string: Required for certificate authentication. The name of a PEM file containing a certificate that will be presented to the peer during authentication.
options : private_key: optional string: Optional for certificate authentication. The name of a PEM file containing the private key associated with certificate. If certificate contains the private key, this option may be omitted.
options : psk: optional string: Required for pre-shared key authentication. Specifies a pre-shared key for authentication that must be identical on both sides of the tunnel.

Patch Options: Only patch interfaces support these options.

options : peer: optional string: The name of the Interface for the other side of the patch. The named Interface's own peer option must specify this Interface's name. That is, the two patch interfaces must have reversed name and peer values.

Interface Status: Status information about interfaces attached to bridges, updated every 5 seconds. Not all interfaces have all of these properties; virtual interfaces don't have a link speed, for example. Non-applicable columns will have empty values.

admin_state: optional string, either down or up: The administrative state of the physical network link.
link_state: optional string, either down or up: The observed state of the physical network link. This is ordinarily the link's carrier status. If the interface's Port is a bond configured for miimon monitoring, it is instead the network link's miimon status.
link_resets: optional integer: The number of times Open vSwitch has observed the link_state of this Interface change.
link_speed: optional integer: The negotiated speed of the physical network link. Valid values are positive integers greater than 0.
duplex: optional string, either full or half: The duplex mode of the physical network link.
mtu: optional integer: The MTU (maximum transmission unit); i.e. the largest amount of data that can fit into a single Ethernet frame. The standard Ethernet MTU is 1500 bytes. Some physical media and many kinds of virtual interfaces can be configured with higher MTUs.
: This column will be empty for an interface that does not have an MTU as, for example, some kinds of tunnels do not.
lacp_current: optional boolean: Boolean value indicating LACP status for this interface. If true, this interface has current LACP information about its LACP partner. This information may be used to monitor the health of interfaces in a LACP enabled port. This column will be empty if LACP is not enabled.
status: map of string-string pairs: Key-value pairs that report port status. Supported status values are type-dependent; some interfaces may not have a valid status:driver_name, for example.
status : driver_name: optional string: The name of the device driver controlling the network adapter.
status : driver_version: optional string: The version string of the device driver controlling the network adapter.
status : firmware_version: optional string: The version string of the network adapter's firmware, if available.
status : source_ip: optional string: The source IP address used for an IPv4 tunnel end-point, such as gre or capwap.
status : tunnel_egress_iface: optional string: Egress interface for tunnels. Currently only relevant for GRE and CAPWAP tunnels. On Linux systems, this column will show the name of the interface which is responsible for routing traffic destined for the configured options:remote_ip. This could be an internal interface such as a bridge port.
status : tunnel_egress_iface_carrier: optional string, either down or up: Whether carrier is detected on status:tunnel_egress_iface.

Statistics: Key-value pairs that report interface statistics. The current implementation updates these counters periodically. Future implementations may update them when an interface is created, when they are queried (e.g. using an OVSDB select operation), and just before an interface is deleted due to virtual interface hot-unplug or VM shutdown, and perhaps at other times, but not on any regular periodic basis.

These are the same statistics reported by OpenFlow in its struct ofp_port_stats structure. If an interface does not support a given statistic, then that pair is omitted.

Statistics: Successful transmit and receive counters:

statistics : rx_packets: optional integer: Number of received packets.
statistics : rx_bytes: optional integer: Number of received bytes.
statistics : tx_packets: optional integer: Number of transmitted packets.
statistics : tx_bytes: optional integer: Number of transmitted bytes.

Statistics: Receive errors:

statistics : rx_dropped: optional integer: Number of packets dropped by RX.
statistics : rx_frame_err: optional integer: Number of frame alignment errors.
statistics : rx_over_err: optional integer: Number of packets with RX overrun.
statistics : rx_crc_err: optional integer: Number of CRC errors.
statistics : rx_errors: optional integer: Total number of receive errors, greater than or equal to the sum of the above.

Statistics: Transmit errors:

statistics : tx_dropped: optional integer: Number of packets dropped by TX.
statistics : collisions: optional integer: Number of collisions.
statistics : tx_errors: optional integer: Total number of transmit errors, greater than or equal to the sum of the above.

Ingress Policing: These settings control ingress policing for packets received on this interface. On a physical interface, this limits the rate at which traffic is allowed into the system from the outside; on a virtual interface (one connected to a virtual machine), this limits the rate at which the VM is able to transmit.

Policing is a simple form of quality-of-service that simply drops packets received in excess of the configured rate. Due to its simplicity, policing is usually less accurate and less effective than egress QoS (which is configured using the QoS and Queue tables).

Policing is currently implemented only on Linux. The Linux implementation uses a simple ``token bucket'' approach:

The size of the bucket corresponds to ingress_policing_burst. Initially the bucket is full.
Whenever a packet is received, its size (converted to tokens) is compared to the number of tokens currently in the bucket. If the required number of tokens are available, they are removed and the packet is forwarded. Otherwise, the packet is dropped.
Whenever it is not full, the bucket is refilled with tokens at the rate specified by ingress_policing_rate.

Policing interacts badly with some network protocols, and especially with fragmented IP packets. Suppose that there is enough network activity to keep the bucket nearly empty all the time. Then this token bucket algorithm will forward a single packet every so often, with the period depending on packet size and on the configured rate. All of the fragments of an IP packets are normally transmitted back-to-back, as a group. In such a situation, therefore, only one of these fragments will be forwarded and the rest will be dropped. IP does not provide any way for the intended recipient to ask for only the remaining fragments. In such a case there are two likely possibilities for what will happen next: either all of the fragments will eventually be retransmitted (as TCP will do), in which case the same problem will recur, or the sender will not realize that its packet has been dropped and data will simply be lost (as some UDP-based protocols will do). Either way, it is possible that no forward progress will ever occur.

ingress_policing_rate: integer, at least 0: Maximum rate for data received on this interface, in kbps. Data received faster than this rate is dropped. Set to 0 (the default) to disable policing.
ingress_policing_burst: integer, at least 0: Maximum burst size for data received on this interface, in kb. The default burst size if set to 0 is 1000 kb. This value has no effect if ingress_policing_rate is 0.
: Specifying a larger burst size lets the algorithm be more forgiving, which is important for protocols like TCP that react severely to dropped packets. The burst size should be at least the size of the interface's MTU. Specifying a value that is numerically at least as large as 10% of ingress_policing_rate helps TCP come closer to achieving the full rate.

Connectivity Fault Management: 802.1ag Connectivity Fault Management (CFM) allows a group of Maintenance Points (MPs) called a Maintenance Association (MA) to detect connectivity problems with each other. MPs within a MA should have complete and exclusive interconnectivity. This is verified by occasionally broadcasting Continuity Check Messages (CCMs) at a configurable transmission interval.

According to the 802.1ag specification, each Maintenance Point should be configured out-of-band with a list of Remote Maintenance Points it should have connectivity to. Open vSwitch differs from the specification in this area. It simply assumes the link is faulted if no Remote Maintenance Points are reachable, and considers it not faulted otherwise.

cfm_mpid: optional integer: A Maintenance Point ID (MPID) uniquely identifies each endpoint within a Maintenance Association. The MPID is used to identify this endpoint to other Maintenance Points in the MA. Each end of a link being monitored should have a different MPID. Must be configured to enable CFM on this Interface.
cfm_fault: optional boolean: Indicates a connectivity fault triggered by an inability to receive heartbeats from any remote endpoint. When a fault is triggered on Interfaces participating in bonds, they will be disabled.
: Faults can be triggered for several reasons. Most importantly they are triggered when no CCMs are received for a period of 3.5 times the transmission interval. Faults are also triggered when any CCMs indicate that a Remote Maintenance Point is not receiving CCMs but able to send them. Finally, a fault is triggered if a CCM is received which indicates unexpected configuration. Notably, this case arises when a CCM is received which advertises the local MPID.
cfm_remote_mpids: set of integers: When CFM is properly configured, Open vSwitch will occasionally receive CCM broadcasts. These broadcasts contain the MPID of the sending Maintenance Point. The list of MPIDs from which this Interface is receiving broadcasts from is regularly collected and written to this column.
other_config : cfm_interval: optional string, containing an integer: The interval, in milliseconds, between transmissions of CFM heartbeats. Three missed heartbeat receptions indicate a connectivity fault. Defaults to 1000.
other_config : cfm_extended: optional string, either true or false: When true, the CFM module operates in extended mode. This causes it to use a nonstandard destination address to avoid conflicting with compliant implementations which may be running concurrently on the network. Furthermore, extended mode increases the accuracy of the cfm_interval configuration parameter by breaking wire compatibility with 802.1ag compliant implementations. Defaults to false.
other_config : cfm_opstate: optional string, either down or up: When down, the CFM module marks all CCMs it generates as operationally down without triggering a fault. This allows remote maintenance points to choose not to forward traffic to the Interface on which this CFM module is running. Currently, in Open vSwitch, the opdown bit of CCMs affects Interfaces participating in bonds, and the bundle OpenFlow action. This setting is ignored when CFM is not in extended mode. Defaults to up.
other_config : cfm_ccm_vlan: optional string, containing an integer, in range 1 to 4,095: When set, the CFM module will apply a VLAN tag to all CCMs it generates with the given value.

Bonding Configuration:

other_config : bond-stable-id: optional string, containing an integer, at least 1: Used in stable bond mode to make slave selection decisions. Allocating other_config:bond-stable-id values consistently across interfaces participating in a bond will guarantee consistent slave selection decisions across ovs-vswitchd instances when using stable bonding mode.
other_config : lacp-port-id: optional string, containing an integer, in range 1 to 65,535: The LACP port ID of this Interface. Port IDs are used in LACP negotiations to identify individual ports participating in a bond.
other_config : lacp-port-priority: optional string, containing an integer, in range 1 to 65,535: The LACP port priority of this Interface. In LACP negotiations Interfaces with numerically lower priorities are preferred for aggregation.
other_config : lacp-aggregation-key: optional string, containing an integer, in range 1 to 65,535: The LACP aggregation key of this Interface. Interfaces with different aggregation keys may not be active within a given Port at the same time.

Virtual Machine Identifiers: These key-value pairs specifically apply to an interface that represents a virtual Ethernet interface connected to a virtual machine. These key-value pairs should not be present for other types of interfaces. Keys whose names end in -uuid have values that uniquely identify the entity in question. For a Citrix XenServer hypervisor, these values are UUIDs in RFC 4122 format. Other hypervisors may use other formats.

external_ids : attached-mac: optional string: The MAC address programmed into the ``virtual hardware'' for this interface, in the form xx:xx:xx:xx:xx:xx. For Citrix XenServer, this is the value of the MAC field in the VIF record for this interface.
external_ids : iface-id: optional string: A system-unique identifier for the interface. On XenServer, this will commonly be the same as external_ids:xs-vif-uuid.
external_ids : xs-vif-uuid: optional string: The virtual interface associated with this interface.
external_ids : xs-network-uuid: optional string: The virtual network to which this interface is attached.
external_ids : xs-vm-uuid: optional string: The VM to which this interface belongs.

VLAN Splinters: The ``VLAN splinters'' feature increases Open vSwitch compatibility with buggy network drivers in old versions of Linux that do not properly support VLANs when VLAN devices are not used, at some cost in memory and performance.

When VLAN splinters are enabled on a particular interface, Open vSwitch creates a VLAN device for each in-use VLAN. For sending traffic tagged with a VLAN on the interface, it substitutes the VLAN device. Traffic received on the VLAN device is treated as if it had been received on the interface on the particular VLAN.

VLAN splinters consider a VLAN to be in use if:

The VLAN is the tag value in any Port record.
The VLAN is listed within the trunks column of the Port record of an interface on which VLAN splinters are enabled. An empty trunks does not influence the in-use VLANs: creating 4,096 VLAN devices is impractical because it will exceed the current 1,024 port per datapath limit.
An OpenFlow flow within any bridge matches the VLAN.

The same set of in-use VLANs applies to every interface on which VLAN splinters are enabled. That is, the set is not chosen separately for each interface but selected once as the union of all in-use VLANs based on the rules above.

It does not make sense to enable VLAN splinters on an interface for an access port, or on an interface that is not a physical port.

VLAN splinters are deprecated. When broken device drivers are no longer in widespread use, we will delete this feature.

other_config : enable-vlan-splinters: optional string, either true or false: Set to true to enable VLAN splinters on this interface. Defaults to false.
: VLAN splinters increase kernel and userspace memory overhead, so do not use them unless they are needed.
: VLAN splinters do not support 802.1p priority tags. Received priorities will appear to be 0, regardless of their actual values, and priorities on transmitted packets will also be cleared to 0.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

QoS TABLE

Quality of Service (QoS) configuration for each Port that references it.

Summary:

type: string
queues: map of integer-Queue pairs, key in range 0 to 4,294,967,295
Configuration for linux-htb and linux-hfsc:
Common Columns:

Details:

type: string

The type of QoS to implement. The capabilities column in the Open_vSwitch table identifies the types that a switch actually supports. The currently defined types are listed below:

linux-htb: Linux ``hierarchy token bucket'' classifier. See tc-htb(8) (also at http://linux.die.net/man/8/tc-htb) and the HTB manual (http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm) for information on how this classifier works and how to configure it.

linux-hfsc: Linux "Hierarchical Fair Service Curve" classifier. See http://linux-ip.net/articles/hfsc.en/ for information on how this classifier works.

queues: map of integer-Queue pairs, key in range 0 to 4,294,967,295

A map from queue numbers to Queue records. The supported range of queue numbers depend on type. The queue numbers are the same as the queue_id used in OpenFlow in struct ofp_action_enqueue and other structures.

Queue 0 is the ``default queue.'' It is used by OpenFlow output actions when no specific queue has been set. Ordinarily queues should include a configuration for queue 0. When no configuration for queue 0 is present, a default configuration is used. (Before version 1.6, Open vSwitch would leave queue 0 unconfigured in this case. With some queuing disciplines, this dropped all packets destined for the default queue.)

Configuration for linux-htb and linux-hfsc: The linux-htb and linux-hfsc classes support the following key-value pair:

other_config : max-rate: optional string, containing an integer: Maximum rate shared by all queued traffic, in bit/s. Optional. If not specified, for physical interfaces, the default is the link rate. For other interfaces or if the link rate cannot be determined, the default is currently 100 Mbps.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

Queue TABLE

A configuration for a port output queue, used in configuring Quality of Service (QoS) features. May be referenced by queues column in QoS table.

Summary:

dscp: optional integer, in range 0 to 63
Configuration for min-rate QoS:
Configuration for linux-htb QoS:
Configuration for linux-hfsc QoS:
Common Columns:

Details:

dscp: optional integer, in range 0 to 63: If set, Open vSwitch will mark all traffic egressing this Queue with the given DSCP bits. Traffic egressing the default Queue is only marked if it was explicitly selected as the Queue at the time the packet was output. If unset, the DSCP bits of traffic egressing this Queue will remain unchanged.

Configuration for min-rate QoS: These key-value pairs are defined for QoS type of min-rate.

other_config : min-rate: optional string, containing an integer, at least 12,000: Minimum guaranteed bandwidth, in bit/s. Required. The floor value is 1500 bytes/s (12,000 bit/s).

Configuration for linux-htb QoS: These key-value pairs are defined for QoS type of linux-htb.

other_config : min-rate: optional string, containing an integer, at least 1: Minimum guaranteed bandwidth, in bit/s.
other_config : max-rate: optional string, containing an integer, at least 1: Maximum allowed bandwidth, in bit/s. Optional. If specified, the queue's rate will not be allowed to exceed the specified value, even if excess bandwidth is available. If unspecified, defaults to no limit.
other_config : burst: optional string, containing an integer, at least 1: Burst size, in bits. This is the maximum amount of ``credits'' that a queue can accumulate while it is idle. Optional. Details of the linux-htb implementation require a minimum burst size, so a too-small burst will be silently ignored.
other_config : priority: optional string, containing an integer, in range 0 to 4,294,967,295: A queue with a smaller priority will receive all the excess bandwidth that it can use before a queue with a larger value receives any. Specific priority values are unimportant; only relative ordering matters. Defaults to 0 if unspecified.

Configuration for linux-hfsc QoS: These key-value pairs are defined for QoS type of linux-hfsc.

other_config : min-rate: optional string, containing an integer, at least 1: Minimum guaranteed bandwidth, in bit/s.
other_config : max-rate: optional string, containing an integer, at least 1: Maximum allowed bandwidth, in bit/s. Optional. If specified, the queue's rate will not be allowed to exceed the specified value, even if excess bandwidth is available. If unspecified, defaults to no limit.

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

other_config: map of string-string pairs
external_ids: map of string-string pairs

Mirror TABLE

A port mirror within a Bridge.

A port mirror configures a bridge to send selected frames to special ``mirrored'' ports, in addition to their normal destinations. Mirroring traffic may also be referred to as SPAN or RSPAN, depending on how the mirrored traffic is sent.

Summary:

name: string
Selecting Packets for Mirroring:
Mirroring Destination Configuration:
Statistics: Mirror counters:
Common Columns:

Details:

name: string: Arbitrary identifier for the Mirror.

Selecting Packets for Mirroring: To be selected for mirroring, a given packet must enter or leave the bridge through a selected port and it must also be in one of the selected VLANs.

select_all: boolean: If true, every packet arriving or departing on any port is selected for mirroring.
select_dst_port: set of weak reference to Ports: Ports on which departing packets are selected for mirroring.
select_src_port: set of weak reference to Ports: Ports on which arriving packets are selected for mirroring.
select_vlan: set of up to 4,096 integers, in range 0 to 4,095: VLANs on which packets are selected for mirroring. An empty set selects packets on all VLANs.

Mirroring Destination Configuration: These columns are mutually exclusive. Exactly one of them must be nonempty.

output_port: optional weak reference to Port

Output port for selected packets, if nonempty.

Specifying a port for mirror output reserves that port exclusively for mirroring. No frames other than those selected for mirroring via this column will be forwarded to the port, and any frames received on the port will be discarded.

The output port may be any kind of port supported by Open vSwitch. It may be, for example, a physical port (sometimes called SPAN) or a GRE tunnel.

output_vlan: optional integer, in range 1 to 4,095

Output VLAN for selected packets, if nonempty.

The frames will be sent out all ports that trunk output_vlan, as well as any ports with implicit VLAN output_vlan. When a mirrored frame is sent out a trunk port, the frame's VLAN tag will be set to output_vlan, replacing any existing tag; when it is sent out an implicit VLAN port, the frame will not be tagged. This type of mirroring is sometimes called RSPAN.

The following destination MAC addresses will not be mirrored to a VLAN to avoid confusing switches that interpret the protocols that they represent:

01:80:c2:00:00:00: IEEE 802.1D Spanning Tree Protocol (STP).
01:80:c2:00:00:01: IEEE Pause frame.
01:80:c2:00:00:0x: Other reserved protocols.
01:00:0c:cc:cc:cc: Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP), Dynamic Trunking Protocol (DTP), Port Aggregation Protocol (PAgP), and others.
01:00:0c:cc:cc:cd: Cisco Shared Spanning Tree Protocol PVSTP+.
01:00:0c:cd:cd:cd: Cisco STP Uplink Fast.
01:00:0c:00:00:00: Cisco Inter Switch Link.

Please note: Mirroring to a VLAN can disrupt a network that contains unmanaged switches. Consider an unmanaged physical switch with two ports: port 1, connected to an end host, and port 2, connected to an Open vSwitch configured to mirror received packets into VLAN 123 on port 2. Suppose that the end host sends a packet on port 1 that the physical switch forwards to port 2. The Open vSwitch forwards this packet to its destination and then reflects it back on port 2 in VLAN 123. This reflected packet causes the unmanaged physical switch to replace the MAC learning table entry, which correctly pointed to port 1, with one that incorrectly points to port 2. Afterward, the physical switch will direct packets destined for the end host to the Open vSwitch on port 2, instead of to the end host on port 1, disrupting connectivity. If mirroring to a VLAN is desired in this scenario, then the physical switch must be replaced by one that learns Ethernet addresses on a per-VLAN basis. In addition, learning should be disabled on the VLAN containing mirrored traffic. If this is not done then intermediate switches will learn the MAC address of each end host from the mirrored traffic. If packets being sent to that end host are also mirrored, then they will be dropped since the switch will attempt to send them out the input port. Disabling learning for the VLAN will cause the switch to correctly send the packet out all ports configured for that VLAN. If Open vSwitch is being used as an intermediate switch, learning can be disabled by adding the mirrored VLAN to flood_vlans in the appropriate Bridge table or tables.

Mirroring to a GRE tunnel has fewer caveats than mirroring to a VLAN and should generally be preferred.

Statistics: Mirror counters: Key-value pairs that report mirror statistics.

statistics : tx_packets: optional integer: Number of packets transmitted through this mirror.
statistics : tx_bytes: optional integer: Number of bytes transmitted through this mirror.

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

Controller TABLE

An OpenFlow controller.

Open vSwitch supports two kinds of OpenFlow controllers:

Primary controllers: This is the kind of controller envisioned by the OpenFlow 1.0 specification. Usually, a primary controller implements a network policy by taking charge of the switch's flow table.
: Open vSwitch initiates and maintains persistent connections to primary controllers, retrying the connection each time it fails or drops. The fail_mode column in the Bridge table applies to primary controllers.
: Open vSwitch permits a bridge to have any number of primary controllers. When multiple controllers are configured, Open vSwitch connects to all of them simultaneously. Because OpenFlow 1.0 does not specify how multiple controllers coordinate in interacting with a single switch, more than one primary controller should be specified only if the controllers are themselves designed to coordinate with each other. (The Nicira-defined NXT_ROLE OpenFlow vendor extension may be useful for this.)
Service controllers: These kinds of OpenFlow controller connections are intended for occasional support and maintenance use, e.g. with ovs-ofctl. Usually a service controller connects only briefly to inspect or modify some of a switch's state.
: Open vSwitch listens for incoming connections from service controllers. The service controllers initiate and, if necessary, maintain the connections from their end. The fail_mode column in the Bridge table does not apply to service controllers.
: Open vSwitch supports configuring any number of service controllers.

The target determines the type of controller.

Summary:

Core Features:
Controller Failure Detection and Handling:
OpenFlow Rate Limiting:
Additional In-Band Configuration:
Controller Status:
Common Columns:

Details:

Core Features:

target: string

Connection method for controller.

The following connection methods are currently supported for primary controllers:

ssl:ip[:port]: The specified SSL port (default: 6633) on the host at the given ip, which must be expressed as an IP address (not a DNS name). The ssl column in the Open_vSwitch table must point to a valid SSL configuration when this form is used.
: SSL support is an optional feature that is not always built as part of Open vSwitch.
tcp:ip[:port]: The specified TCP port (default: 6633) on the host at the given ip, which must be expressed as an IP address (not a DNS name).

The following connection methods are currently supported for service controllers:

pssl:[port][:ip]: Listens for SSL connections on the specified TCP port (default: 6633). If ip, which must be expressed as an IP address (not a DNS name), is specified, then connections are restricted to the specified local IP address.
: The ssl column in the Open_vSwitch table must point to a valid SSL configuration when this form is used.
: SSL support is an optional feature that is not always built as part of Open vSwitch.
ptcp:[port][:ip]: Listens for connections on the specified TCP port (default: 6633). If ip, which must be expressed as an IP address (not a DNS name), is specified, then connections are restricted to the specified local IP address.

When multiple controllers are configured for a single bridge, the target values must be unique. Duplicate target values yield unspecified results.

connection_mode: optional string, either in-band or out-of-band

If it is specified, this setting must be one of the following strings that describes how Open vSwitch contacts this OpenFlow controller over the network:

in-band: In this mode, this controller's OpenFlow traffic travels over the bridge associated with the controller. With this setting, Open vSwitch allows traffic to and from the controller regardless of the contents of the OpenFlow flow table. (Otherwise, Open vSwitch would never be able to connect to the controller, because it did not have a flow to enable it.) This is the most common connection mode because it is not necessary to maintain two independent networks.
out-of-band: In this mode, OpenFlow traffic uses a control network separate from the bridge associated with this controller, that is, the bridge does not use any of its own network devices to communicate with the controller. The control network must be configured separately, before or after ovs-vswitchd is started.

If not specified, the default is implementation-specific.

Controller Failure Detection and Handling:

max_backoff: optional integer, at least 1,000: Maximum number of milliseconds to wait between connection attempts. Default is implementation-specific.
inactivity_probe: optional integer: Maximum number of milliseconds of idle time on connection to controller before sending an inactivity probe message. If Open vSwitch does not communicate with the controller for the specified number of seconds, it will send a probe. If a response is not received for the same additional amount of time, Open vSwitch assumes the connection has been broken and attempts to reconnect. Default is implementation-specific. A value of 0 disables inactivity probes.

OpenFlow Rate Limiting:

controller_rate_limit: optional integer, at least 100: The maximum rate at which packets in unknown flows will be forwarded to the OpenFlow controller, in packets per second. This feature prevents a single bridge from overwhelming the controller. If not specified, the default is implementation-specific.
: In addition, when a high rate triggers rate-limiting, Open vSwitch queues controller packets for each port and transmits them to the controller at the configured rate. The number of queued packets is limited by the controller_burst_limit value. The packet queue is shared fairly among the ports on a bridge.
: Open vSwitch maintains two such packet rate-limiters per bridge. One of these applies to packets sent up to the controller because they do not correspond to any flow. The other applies to packets sent up to the controller by request through flow actions. When both rate-limiters are filled with packets, the actual rate that packets are sent to the controller is up to twice the specified rate.
controller_burst_limit: optional integer, at least 25: In conjunction with controller_rate_limit, the maximum number of unused packet credits that the bridge will allow to accumulate, in packets. If not specified, the default is implementation-specific.

Additional In-Band Configuration: These values are considered only in in-band control mode (see connection_mode).

When multiple controllers are configured on a single bridge, there should be only one set of unique values in these columns. If different values are set for these columns in different controllers, the effect is unspecified.

local_ip: optional string: The IP address to configure on the local port, e.g. 192.168.0.123. If this value is unset, then local_netmask and local_gateway are ignored.
local_netmask: optional string: The IP netmask to configure on the local port, e.g. 255.255.255.0. If local_ip is set but this value is unset, then the default is chosen based on whether the IP address is class A, B, or C.
local_gateway: optional string: The IP address of the gateway to configure on the local port, as a string, e.g. 192.168.0.1. Leave this column unset if this network has no gateway.

Controller Status:

is_connected: boolean

true if currently connected to this controller, false otherwise.

role: optional string, one of slave, other, or master

The level of authority this controller has on the associated bridge. Possible values are:

other: Allows the controller access to all OpenFlow features.
master: Equivalent to other, except that there may be at most one master controller at a time. When a controller configures itself as master, any existing master is demoted to the slaverole.
slave: Allows the controller read-only access to OpenFlow features. Attempts to modify the flow table will be rejected with an error. Slave controllers do not receive OFPT_PACKET_IN or OFPT_FLOW_REMOVED messages, but they do receive OFPT_PORT_STATUS messages.

status : last_error: optional string

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

status : state: optional string, one of ACTIVE, VOID, CONNECTING, IDLE, or BACKOFF

The state of the connection to the controller:

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 controller last successfully connected to the switch (in seconds). Value is empty if controller has never successfully connected.

status : sec_since_disconnect: optional string, containing an integer, at least 1

The amount of time since this controller last disconnected from the switch (in seconds). Value is empty if controller has never disconnected.

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

Manager TABLE

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

This table primarily configures the Open vSwitch database (ovsdb-server), not the Open vSwitch switch (ovs-vswitchd). The switch does read the table to determine what connections should be treated as in-band.

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

Summary:

Core Features:
Client Failure Detection and Handling:
Status:
Common Columns:

Details:

Core Features:

target: string (must be unique within table)

Connection method for managers.

The following connection methods are currently supported:

ssl:ip[:port]: The specified SSL port (default: 6632) on the host at the given ip, which must be expressed as an IP address (not a DNS name). The ssl column in the Open_vSwitch table must point to a valid SSL configuration when this form is used.
: SSL support is an optional feature that is not always built as part of Open vSwitch.
tcp:ip[:port]: The specified TCP port (default: 6632) on the host at the given ip, which must be expressed as an IP address (not a DNS name).
pssl:[port][:ip]: Listens for SSL connections on the specified TCP port (default: 6632). If ip, which must be expressed as an IP address (not a DNS name), is specified, then connections are restricted to the specified local IP address.
: The ssl column in the Open_vSwitch table must point to a valid SSL configuration when this form is used.
: SSL support is an optional feature that is not always built as part of Open vSwitch.
ptcp:[port][:ip]: Listens for connections on the specified TCP port (default: 6632). If ip, which must be expressed as an IP address (not a DNS name), is specified, then connections are restricted to the specified local IP address.

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

connection_mode: optional string, either in-band or out-of-band

If it is specified, this setting must be one of the following strings that describes how Open vSwitch contacts this OVSDB client over the network:

in-band: In this mode, this connection's traffic travels over a bridge managed by Open vSwitch. With this setting, Open vSwitch allows traffic to and from the client regardless of the contents of the OpenFlow flow table. (Otherwise, Open vSwitch would never be able to connect to the client, because it did not have a flow to enable it.) This is the most common connection mode because it is not necessary to maintain two independent networks.
out-of-band: In this mode, the client's traffic uses a control network separate from that managed by Open vSwitch, that is, Open vSwitch does not use any of its own network devices to communicate with the client. The control network must be configured separately, before or after ovs-vswitchd is started.

If not specified, the default is implementation-specific.

Client Failure Detection and Handling:

max_backoff: optional integer, at least 1,000: Maximum number of milliseconds to wait between connection attempts. Default is implementation-specific.
inactivity_probe: optional integer: Maximum number of milliseconds of idle time on connection to the client before sending an inactivity probe message. If Open vSwitch does not communicate with the client for the specified number of seconds, it will send a probe. If a response is not received for the same additional amount of time, Open vSwitch assumes the connection has been broken and attempts to reconnect. Default is implementation-specific. A value of 0 disables inactivity probes.

Status:

is_connected: boolean

true if currently connected to this manager, 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, VOID, CONNECTING, IDLE, or BACKOFF

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 manager last successfully connected to the database (in seconds). Value is empty if manager has never successfully connected.

status : sec_since_disconnect: optional string, containing an integer, at least 0

The amount of time since this manager last disconnected from the database (in seconds). Value is empty if manager has never disconnected.

status : locks_held: optional string

Space-separated list of the names of OVSDB locks that the connection holds. Omitted if the connection does not hold any locks.

status : locks_waiting: optional string

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

status : locks_lost: optional string

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

status : n_connections: optional string, containing an integer, at least 2

When target specifies a connection method that listens for inbound connections (e.g. ptcp: or pssl:) and more than one connection is actually active, the value is the number of active connections. Otherwise, this key-value pair is omitted.

When multiple connections are active, status columns and key-value pairs (other than this one) report the status of one arbitrarily chosen connection.

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

NetFlow TABLE

A NetFlow target. NetFlow is a protocol that exports a number of details about terminating IP flows, such as the principals involved and duration.

Summary:

targets: set of 1 or more strings
engine_id: optional integer, in range 0 to 255
engine_type: optional integer, in range 0 to 255
active_timeout: integer, at least -1
add_id_to_interface: boolean
Common Columns:

Details:

targets: set of 1 or more strings: NetFlow targets in the form ip:port. The ip must be specified numerically, not as a DNS name.
engine_id: optional integer, in range 0 to 255: Engine ID to use in NetFlow messages. Defaults to datapath index if not specified.
engine_type: optional integer, in range 0 to 255: Engine type to use in NetFlow messages. Defaults to datapath index if not specified.
active_timeout: integer, at least -1: The interval at which NetFlow records are sent for flows that are still active, in seconds. A value of 0 requests the default timeout (currently 600 seconds); a value of -1 disables active timeouts.
add_id_to_interface: boolean: If this column's value is false, the ingress and egress interface fields of NetFlow flow records are derived from OpenFlow port numbers. When it is true, the 7 most significant bits of these fields will be replaced by the least significant 7 bits of the engine id. This is useful because many NetFlow collectors do not expect multiple switches to be sending messages from the same host, so they do not store the engine information which could be used to disambiguate the traffic.
: When this option is enabled, a maximum of 508 ports are supported.

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

SSL TABLE

SSL configuration for an Open_vSwitch.

Summary:

private_key: string
certificate: string
ca_cert: string
bootstrap_ca_cert: boolean
Common Columns:

Details:

private_key: string: Name of a PEM file containing the private key used as the switch's identity for SSL connections to the controller.
certificate: string: Name of a PEM file containing a certificate, signed by the certificate authority (CA) used by the controller and manager, that certifies the switch's private key, identifying a trustworthy switch.
ca_cert: string: Name of a PEM file containing the CA certificate used to verify that the switch is connected to a trustworthy controller.
bootstrap_ca_cert: boolean: If set to true, then Open vSwitch will attempt to obtain the CA certificate from the controller on its first SSL connection and save it to the named PEM file. If it is successful, it will immediately drop the connection and reconnect, and from then on all SSL connections must be authenticated by a certificate signed by the CA certificate thus obtained. This option exposes the SSL connection to a man-in-the-middle attack obtaining the initial CA certificate. It may still be useful for bootstrapping.

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

sFlow TABLE

An sFlow(R) target. sFlow is a protocol for remote monitoring of switches.

Summary:

agent: optional string
header: optional integer
polling: optional integer
sampling: optional integer
targets: set of 1 or more strings
Common Columns:

Details:

agent: optional string: Name of the network device whose IP address should be reported as the ``agent address'' to collectors. If not specified, the IP address defaults to the local_ip in the collector's Controller. If an agent IP address cannot be determined either way, sFlow is disabled.
header: optional integer: Number of bytes of a sampled packet to send to the collector. If not specified, the default is 128 bytes.
polling: optional integer: Polling rate in seconds to send port statistics to the collector. If not specified, defaults to 30 seconds.
sampling: optional integer: Rate at which packets should be sampled and sent to the collector. If not specified, defaults to 400, which means one out of 400 packets, on average, will be sent to the collector.
targets: set of 1 or more strings: sFlow targets in the form ip: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

Capability TABLE

Records in this table describe functionality supported by the hardware and software platform on which this Open vSwitch is based. Clients should not modify this table.

A record in this table is meaningful only if it is referenced by the capabilities column in the Open_vSwitch table. The key used to reference it, called the record's ``category,'' determines the meanings of the details column. The following general forms of categories are currently defined:

qos-type: type is supported as the value for type in the QoS table.

Summary:

details: map of string-string pairs

Details:

details: map of string-string pairs

Key-value pairs that describe capabilities. The meaning of the pairs depends on the category key that the capabilities column in the Open_vSwitch table uses to reference this record, as described above.

The presence of a record for category qos-type indicates that the switch supports type as the value of the type column in the QoS table. The following key-value pairs are defined to further describe QoS capabilities:

n-queues: Number of supported queues, as a positive integer. Keys in the queues column for QoS records whose type value equals type must range between 0 and this value minus one, inclusive.

Common Columns

TABLE SUMMARY

Open_vSwitch TABLE

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Bridge TABLE

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Port TABLE

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Interface TABLE

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QoS TABLE

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Queue TABLE

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Mirror TABLE

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Controller TABLE

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Manager TABLE

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NetFlow TABLE

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SSL TABLE

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sFlow TABLE

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Capability TABLE

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