1 <?xml version="1.0" encoding="utf-8"?>
2 <database title="Open vSwitch Configuration Database">
3 <p>A database with this schema holds the configuration for one Open
4 vSwitch daemon. The root of the configuration for the daemon is
5 the <ref table="Open_vSwitch"/> table, which must have exactly one
6 record. Records in other tables are significant only when they
7 can be reached directly or indirectly from the
8 <ref table="Open_vSwitch"/> table.</p>
10 <table name="Open_vSwitch" title="Open vSwitch configuration.">
11 Configuration for an Open vSwitch daemon. There must be exactly one record
12 in the <ref table="Open_vSwitch"/> table.
14 <group title="Configuration">
15 <column name="bridges">
16 Set of bridges managed by the daemon.
20 SSL used globally by the daemon.
23 <column name="external_ids">
24 Key-value pairs for use by external frameworks that integrate
25 with Open vSwitch, rather than by Open vSwitch itself. System
26 integrators should either use the Open vSwitch development
27 mailing list to coordinate on common key-value definitions, or
28 choose key names that are likely to be unique. The currently
29 defined common key-value pairs are:
31 <dt><code>system-id</code></dt>
32 <dd>A unique identifier for the Open vSwitch's physical host.
33 The form of the identifier depends on the type of the host.
34 On a Citrix XenServer, this will likely be the same as
35 <code>xs-system-uuid</code>.</dd>
36 <dt><code>xs-system-uuid</code></dt>
37 <dd>The Citrix XenServer universally unique identifier for the
38 physical host as displayed by <code>xe host-list</code>.</dd>
43 <group title="Status">
44 <column name="next_cfg">
45 Sequence number for client to increment. When a client modifies
46 any part of the database configuration and wishes to wait for
47 Open vSwitch to finish applying the changes, it may increment
51 <column name="cur_cfg">
52 Sequence number that Open vSwitch sets to the current value of
53 <ref column="next_cfg"/> after it finishes applying a set of
54 configuration changes.
57 <column name="capabilities">
58 Describes functionality supported by the hardware and software platform
59 on which this Open vSwitch is based. Clients should not modify this
60 column. See the <ref table="Capability"/> description for defined
61 capability categories and the meaning of associated
62 <ref table="Capability"/> records.
65 <column name="statistics">
67 Key-value pairs that report statistics about a system running an Open
68 vSwitch. These are updated periodically (currently, every 5
69 seconds). Key-value pairs that cannot be determined or that do not
70 apply to a platform are omitted.
74 <dt><code>cpu</code></dt>
77 Number of CPU processors, threads, or cores currently online and
78 available to the operating system on which Open vSwitch is
79 running, as an integer. This may be less than the number
80 installed, if some are not online or if they are not available to
84 Open vSwitch userspace processes are not multithreaded, but the
85 Linux kernel-based datapath is.
89 <dt><code>load_average</code></dt>
92 A comma-separated list of three floating-point numbers,
93 representing the system load average over the last 1, 5, and 15
94 minutes, respectively.
98 <dt><code>memory</code></dt>
101 A comma-separated list of integers, each of which represents a
102 quantity of memory in kilobytes that describes the operating
103 system on which Open vSwitch is running. In respective order,
108 <li>Total amount of RAM allocated to the OS.</li>
109 <li>RAM allocated to the OS that is in use.</li>
110 <li>RAM that can be flushed out to disk or otherwise discarded
111 if that space is needed for another purpose. This number is
112 necessarily less than or equal to the previous value.</li>
113 <li>Total disk space allocated for swap.</li>
114 <li>Swap space currently in use.</li>
118 On Linux, all five values can be determined and are included. On
119 other operating systems, only the first two values can be
120 determined, so the list will only have two values.
124 <dt><code>process_</code><var>name</var></dt>
127 One such key-value pair will exist for each running Open vSwitch
128 daemon process, with <var>name</var> replaced by the daemon's
129 name (e.g. <code>process_ovs-vswitchd</code>). The value is a
130 comma-separated list of integers. The integers represent the
131 following, with memory measured in kilobytes and durations in
136 <li>The process's virtual memory size.</li>
137 <li>The process's resident set size.</li>
138 <li>The amount of user and system CPU time consumed by the
140 <li>The number of times that the process has crashed and been
141 automatically restarted by the monitor.</li>
142 <li>The duration since the process was started.</li>
143 <li>The duration for which the process has been running.</li>
147 The interpretation of some of these values depends on whether the
148 process was started with the <option>--monitor</option>. If it
149 was not, then the crash count will always be 0 and the two
150 durations will always be the same. If <option>--monitor</option>
151 was given, then the crash count may be positive; if it is, the
152 latter duration is the amount of time since the most recent crash
157 There will be one key-value pair for each file in Open vSwitch's
158 ``run directory'' (usually <code>/var/run/openvswitch</code>)
159 whose name ends in <code>.pid</code>, whose contents are a
160 process ID, and which is locked by a running process. The
161 <var>name</var> is taken from the pidfile's name.
165 Currently Open vSwitch is only able to obtain all of the above
166 detail on Linux systems. On other systems, the same key-value
167 pairs will be present but the values will always be the empty
172 <dt><code>file_systems</code></dt>
175 A space-separated list of information on local, writable file
176 systems. Each item in the list describes one file system and
177 consists in turn of a comma-separated list of the following:
181 <li>Mount point, e.g. <code>/</code> or <code>/var/log</code>.
182 Any spaces or commas in the mount point are replaced by
184 <li>Total size, in kilobytes, as an integer.</li>
185 <li>Amount of storage in use, in kilobytes, as an integer.</li>
189 This key-value pair is omitted if there are no local, writable
190 file systems or if Open vSwitch cannot obtain the needed
198 <group title="Version Reporting">
200 These columns report the types and versions of the hardware and
201 software running Open vSwitch. We recommend in general that software
202 should test whether specific features are supported instead of relying
203 on version number checks. These values are primarily intended for
204 reporting to human administrators.
207 <column name="ovs_version">
208 The Open vSwitch version number, e.g. <code>1.1.0pre2</code>.
209 If Open vSwitch was configured with a build number, then it is
210 also included, e.g. <code>1.1.0pre2+build4948</code>.
213 <column name="db_version">
215 The database schema version number in the form
216 <code><var>major</var>.<var>minor</var>.<var>tweak</var></code>,
217 e.g. <code>1.2.3</code>. Whenever the database schema is changed in
218 a non-backward compatible way (e.g. deleting a column or a table),
219 <var>major</var> is incremented. When the database schema is changed
220 in a backward compatible way (e.g. adding a new column),
221 <var>minor</var> is incremented. When the database schema is changed
222 cosmetically (e.g. reindenting its syntax), <var>tweak</var> is
227 The schema version is part of the database schema, so it can also be
228 retrieved by fetching the schema using the Open vSwitch database
233 <column name="system_type">
235 An identifier for the type of system on top of which Open vSwitch
236 runs, e.g. <code>XenServer</code> or <code>KVM</code>.
239 System integrators are responsible for choosing and setting an
240 appropriate value for this column.
244 <column name="system_version">
246 The version of the system identified by <ref column="system_type"/>,
247 e.g. <code>5.5.0-24648p</code> on XenServer 5.5.0 build 24648.
250 System integrators are responsible for choosing and setting an
251 appropriate value for this column.
257 <group title="Database Configuration">
259 These columns primarily configure the Open vSwitch database
260 (<code>ovsdb-server</code>), not the Open vSwitch switch
261 (<code>ovs-vswitchd</code>). The OVSDB database also uses the <ref
262 column="ssl"/> settings.
266 The Open vSwitch switch does read the database configuration to
267 determine remote IP addresses to which in-band control should apply.
270 <column name="manager_options">
271 Database clients to which the Open vSwitch database server should
272 connect or to which it should listen, along with options for how these
273 connection should be configured. See the <ref table="Manager"/> table
274 for more information.
277 <column name="managers">
279 Remote database clients to which the Open vSwitch's database server
280 should connect or to which it should listen. Adding an OVSDB target
281 to this set is equivalent to adding it to <ref
282 column="manager_options"/> with all of the default options.
286 Use of this column is deprecated and may be removed sometime in the
287 future. New applications should use and set <ref
288 column="manager_options"/> instead.
294 <table name="Bridge">
296 Configuration for a bridge within an
297 <ref table="Open_vSwitch"/>.
300 A <ref table="Bridge"/> record represents an Ethernet switch with one or
301 more ``ports,'' which are the <ref table="Port"/> records pointed to by
302 the <ref table="Bridge"/>'s <ref column="ports"/> column.
305 <group title="Core Features">
307 Bridge identifier. Should be alphanumeric and no more than about 8
308 bytes long. Must be unique among the names of ports, interfaces, and
312 <column name="ports">
313 Ports included in the bridge.
316 <column name="mirrors">
317 Port mirroring configuration.
320 <column name="netflow">
321 NetFlow configuration.
324 <column name="sflow">
328 <column name="flood_vlans">
329 VLAN IDs of VLANs on which MAC address learning should be disabled, so
330 that packets are flooded instead of being sent to specific ports that
331 are believed to contain packets' destination MACs. This should
332 ordinarily be used to disable MAC learning on VLANs used for mirroring
333 (RSPAN VLANs). It may also be useful for debugging.
337 <group title="OpenFlow Configuration">
338 <column name="controller">
339 OpenFlow controller set. If unset, then no OpenFlow controllers
343 <column name="fail_mode">
344 <p>When a controller is configured, it is, ordinarily, responsible
345 for setting up all flows on the switch. Thus, if the connection to
346 the controller fails, no new network connections can be set up.
347 If the connection to the controller stays down long enough,
348 no packets can pass through the switch at all. This setting
349 determines the switch's response to such a situation. It may be set
350 to one of the following:
352 <dt><code>standalone</code></dt>
353 <dd>If no message is received from the controller for three
354 times the inactivity probe interval
355 (see <ref column="inactivity_probe"/>), then Open vSwitch
356 will take over responsibility for setting up flows. In
357 this mode, Open vSwitch causes the bridge to act like an
358 ordinary MAC-learning switch. Open vSwitch will continue
359 to retry connecting to the controller in the background
360 and, when the connection succeeds, it will discontinue its
361 standalone behavior.</dd>
362 <dt><code>secure</code></dt>
363 <dd>Open vSwitch will not set up flows on its own when the
364 controller connection fails or when no controllers are
365 defined. The bridge will continue to retry connecting to
366 any defined controllers forever.</dd>
369 <p>If this value is unset, the default is implementation-specific.</p>
370 <p>When more than one controller is configured,
371 <ref column="fail_mode"/> is considered only when none of the
372 configured controllers can be contacted.</p>
375 <column name="datapath_id">
376 Reports the OpenFlow datapath ID in use. Exactly 16 hex
377 digits. (Setting this column will have no useful effect. Set
378 <ref column="other_config"/>:<code>other-config</code>
383 <group title="Other Features">
384 <column name="datapath_type">
385 Name of datapath provider. The kernel datapath has
386 type <code>system</code>. The userspace datapath has
387 type <code>netdev</code>.
390 <column name="external_ids">
391 Key-value pairs for use by external frameworks that integrate
392 with Open vSwitch, rather than by Open vSwitch itself. System
393 integrators should either use the Open vSwitch development
394 mailing list to coordinate on common key-value definitions, or
395 choose key names that are likely to be unique. The currently
396 defined key-value pairs are:
398 <dt><code>bridge-id</code></dt>
399 <dd>A unique identifier of the bridge. On Citrix XenServer this
400 will commonly be the same as <code>xs-network-uuids</code>.</dd>
401 <dt><code>xs-network-uuids</code></dt>
402 <dd>Semicolon-delimited set of universally unique identifier(s) for
403 the network with which this bridge is associated on a Citrix
404 XenServer host. The network identifiers are RFC 4122 UUIDs as
405 displayed by, e.g., <code>xe network-list</code>.</dd>
409 <column name="other_config">
410 Key-value pairs for configuring rarely used bridge
411 features. The currently defined key-value pairs are:
413 <dt><code>datapath-id</code></dt>
415 digits to set the OpenFlow datapath ID to a specific
416 value. May not be all-zero.</dd>
417 <dt><code>disable-in-band</code></dt>
418 <dd>If set to <code>true</code>, disable in-band control on
419 the bridge regardless of controller and manager settings.</dd>
420 <dt><code>hwaddr</code></dt>
421 <dd>An Ethernet address in the form
422 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>
423 to set the hardware address of the local port and influence the
425 <dt><code>in-band-queue</code></dt>
427 A queue ID as a nonnegative integer. This sets the OpenFlow queue
428 ID that will be used by flows set up by in-band control on this
429 bridge. If unset, or if the port used by an in-band control flow
430 does not have QoS configured, or if the port does not have a queue
431 with the specified ID, the default queue is used instead.
438 <table name="Port" table="Port or bond configuration.">
439 <p>A port within a <ref table="Bridge"/>.</p>
440 <p>Most commonly, a port has exactly one ``interface,'' pointed to by its
441 <ref column="interfaces"/> column. Such a port logically
442 corresponds to a port on a physical Ethernet switch. A port
443 with more than one interface is a ``bonded port'' (see
444 <ref group="Bonding Configuration"/>).</p>
445 <p>Some properties that one might think as belonging to a port are actually
446 part of the port's <ref table="Interface"/> members.</p>
449 Port name. Should be alphanumeric and no more than about 8
450 bytes long. May be the same as the interface name, for
451 non-bonded ports. Must otherwise be unique among the names of
452 ports, interfaces, and bridges on a host.
455 <column name="interfaces">
456 The port's interfaces. If there is more than one, this is a
460 <group title="VLAN Configuration">
461 <p>A bridge port must be configured for VLANs in one of two
462 mutually exclusive ways:
464 <li>A ``trunk port'' has an empty value for <ref
465 column="tag"/>. Its <ref column="trunks"/> value may be
466 empty or non-empty.</li>
467 <li>An ``implicitly tagged VLAN port'' or ``access port''
468 has an nonempty value for <ref column="tag"/>. Its
469 <ref column="trunks"/> value must be empty.</li>
471 If <ref column="trunks"/> and <ref column="tag"/> are both
472 nonempty, the configuration is ill-formed.
477 If this is an access port (see above), the port's implicitly
478 tagged VLAN. Must be empty if this is a trunk port.
481 Frames arriving on trunk ports will be forwarded to this
482 port only if they are tagged with the given VLAN (or, if
483 <ref column="tag"/> is 0, then if they lack a VLAN header).
484 Frames arriving on other access ports will be forwarded to
485 this port only if they have the same <ref column="tag"/>
486 value. Frames forwarded to this port will not have an
490 When a frame with a 802.1Q header that indicates a nonzero
491 VLAN is received on an access port, it is discarded.
495 <column name="trunks">
497 If this is a trunk port (see above), the 802.1Q VLAN(s) that
498 this port trunks; if it is empty, then the port trunks all
499 VLANs. Must be empty if this is an access port.
502 Frames arriving on trunk ports are dropped if they are not
503 in one of the specified VLANs. For this purpose, packets
504 that have no VLAN header are treated as part of VLAN 0.
509 <group title="Bonding Configuration">
510 <p>A port that has more than one interface is a ``bonded port.'' Bonding
511 allows for load balancing and fail-over. Open vSwitch supports
512 ``source load balancing'' (SLB) and "active backup" bonding. SLB
513 bonding assigns flows to slaves based on source MAC address and output
514 VLAN, with periodic rebalancing as traffic patterns change. Active
515 backup bonding assigns all flows to one slave, failing over to a backup
516 slave when the active slave is disabled. Neither form of bonding
517 require 802.3ad or other special support from the upstream switch to
518 which the slave devices are connected.</p>
520 <p>These columns apply only to bonded ports. Their values are
521 otherwise ignored.</p>
523 <column name="bond_mode">
524 <p>The type of bonding used for a bonded port. Currently supported
525 values are <code>balance-slb</code> and <code>active-backup</code>.
526 Defaults to SLB if unset.</p>
529 <column name="bond_updelay">
530 <p>For a bonded port, the number of milliseconds for which carrier must
531 stay up on an interface before the interface is considered to be up.
532 Specify <code>0</code> to enable the interface immediately.</p>
533 <p>This setting is honored only when at least one bonded interface is
534 already enabled. When no interfaces are enabled, then the first bond
535 interface to come up is enabled immediately.</p>
538 <column name="bond_downdelay">
539 For a bonded port, the number of milliseconds for which carrier must
540 stay down on an interface before the interface is considered to be
541 down. Specify <code>0</code> to disable the interface immediately.
544 <column name="bond_fake_iface">
545 For a bonded port, whether to create a fake internal interface with the
546 name of the port. Use only for compatibility with legacy software that
551 <group title="Other Features">
553 Quality of Service configuration for this port.
557 The MAC address to use for this port for the purpose of choosing the
558 bridge's MAC address. This column does not necessarily reflect the
559 port's actual MAC address, nor will setting it change the port's actual
563 <column name="fake_bridge">
564 Does this port represent a sub-bridge for its tagged VLAN within the
565 Bridge? See ovs-vsctl(8) for more information.
568 <column name="external_ids">
570 Key-value pairs for use by external frameworks that integrate with
571 Open vSwitch, rather than by Open vSwitch itself. System integrators
572 should either use the Open vSwitch development mailing list to
573 coordinate on common key-value definitions, or choose key names that
574 are likely to be unique.
577 No key-value pairs native to <ref table="Port"/> are currently
578 defined. For fake bridges (see the <ref column="fake_bridge"/>
579 column), external IDs for the fake bridge are defined here by
580 prefixing a <ref table="Bridge"/> <ref table="Bridge"
581 column="external_ids"/> key with <code>fake-bridge-</code>,
582 e.g. <code>fake-bridge-xs-network-uuids</code>.
586 <column name="other_config">
587 Key-value pairs for configuring rarely used port features. The
588 currently defined key-value pairs are:
590 <dt><code>hwaddr</code></dt>
591 <dd>An Ethernet address in the form
592 <code><var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var></code>.</dd>
593 <dt><code>bond-rebalance-interval</code></dt>
594 <dd>For an SLB bonded port, the number of milliseconds between
595 successive attempts to rebalance the bond, that is, to
596 move source MACs and their flows from one interface on
597 the bond to another in an attempt to keep usage of each
598 interface roughly equal. The default is 10000 (10
599 seconds), and the minimum is 1000 (1 second).</dd>
600 <dt><code>bond-detect-mode</code></dt>
601 <dd> Sets the method used to detect link failures in a bonded port.
602 Options are <code>carrier</code> and <code>miimon</code>. Defaults
603 to <code>carrier</code> which uses each interface's carrier to detect
604 failures. When set to <code>miimon</code>, will check for failures
605 by polling each interface's MII. </dd>
606 <dt><code>bond-miimon-interval</code></dt>
607 <dd> The number of milliseconds between successive attempts to
608 poll each interface's MII. Only relevant on ports which use
609 <code>miimon</code> to detect failures. </dd>
615 <table name="Interface" title="One physical network device in a Port.">
616 An interface within a <ref table="Port"/>.
618 <group title="Core Features">
620 Interface name. Should be alphanumeric and no more than about 8 bytes
621 long. May be the same as the port name, for non-bonded ports. Must
622 otherwise be unique among the names of ports, interfaces, and bridges
627 <p>Ethernet address to set for this interface. If unset then the
628 default MAC address is used:</p>
630 <li>For the local interface, the default is the lowest-numbered MAC
631 address among the other bridge ports, either the value of the
632 <ref table="Port" column="mac"/> in its <ref table="Port"/> record,
633 if set, or its actual MAC (for bonded ports, the MAC of its slave
634 whose name is first in alphabetical order). Internal ports and
635 bridge ports that are used as port mirroring destinations (see the
636 <ref table="Mirror"/> table) are ignored.</li>
637 <li>For other internal interfaces, the default MAC is randomly
639 <li>External interfaces typically have a MAC address associated with
642 <p>Some interfaces may not have a software-controllable MAC
646 <column name="ofport">
647 <p>OpenFlow port number for this interface. Unlike most columns, this
648 column's value should be set only by Open vSwitch itself. Other
649 clients should set this column to an empty set (the default) when
650 creating an <ref table="Interface"/>.</p>
651 <p>Open vSwitch populates this column when the port number becomes
652 known. If the interface is successfully added,
653 <ref column="ofport"/> will be set to a number between 1 and 65535
654 (generally either in the range 1 to 65279, inclusive, or 65534, the
655 port number for the OpenFlow ``local port''). If the interface
656 cannot be added then Open vSwitch sets this column
661 <group title="System-Specific Details">
663 The interface type, one of:
665 <dt><code>system</code></dt>
666 <dd>An ordinary network device, e.g. <code>eth0</code> on Linux.
667 Sometimes referred to as ``external interfaces'' since they are
668 generally connected to hardware external to that on which the Open
669 vSwitch is running. The empty string is a synonym for
670 <code>system</code>.</dd>
671 <dt><code>internal</code></dt>
672 <dd>A simulated network device that sends and receives traffic. An
673 internal interface whose <ref column="name"/> is the same as its
674 bridge's <ref table="Open_vSwitch" column="name"/> is called the
675 ``local interface.'' It does not make sense to bond an internal
676 interface, so the terms ``port'' and ``interface'' are often used
677 imprecisely for internal interfaces.</dd>
678 <dt><code>tap</code></dt>
679 <dd>A TUN/TAP device managed by Open vSwitch.</dd>
680 <dt><code>gre</code></dt>
681 <dd>An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
682 tunnel. Each tunnel must be uniquely identified by the
683 combination of <code>remote_ip</code>, <code>local_ip</code>, and
684 <code>in_key</code>. Note that if two ports are defined that are
685 the same except one has an optional identifier and the other does
686 not, the more specific one is matched first. <code>in_key</code>
687 is considered more specific than <code>local_ip</code> if a port
688 defines one and another port defines the other. The following
689 options may be specified in the <ref column="options"/> column:
691 <dt><code>remote_ip</code></dt>
692 <dd>Required. The tunnel endpoint.</dd>
695 <dt><code>local_ip</code></dt>
696 <dd>Optional. The destination IP that received packets must
697 match. Default is to match all addresses.</dd>
700 <dt><code>in_key</code></dt>
701 <dd>Optional. The GRE key that received packets must contain.
702 It may either be a 32-bit number (no key and a key of 0 are
703 treated as equivalent) or the word <code>flow</code>. If
704 <code>flow</code> is specified then any key will be accepted
705 and the key will be placed in the <code>tun_id</code> field
706 for matching in the flow table. The ovs-ofctl manual page
707 contains additional information about matching fields in
708 OpenFlow flows. Default is no key.</dd>
711 <dt><code>out_key</code></dt>
712 <dd>Optional. The GRE key to be set on outgoing packets. It may
713 either be a 32-bit number or the word <code>flow</code>. If
714 <code>flow</code> is specified then the key may be set using
715 the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0
716 is used in the absence of an action). The ovs-ofctl manual
717 page contains additional information about the Nicira OpenFlow
718 vendor extensions. Default is no key.</dd>
721 <dt><code>key</code></dt>
722 <dd>Optional. Shorthand to set <code>in_key</code> and
723 <code>out_key</code> at the same time.</dd>
726 <dt><code>tos</code></dt>
727 <dd>Optional. The value of the ToS bits to be set on the
728 encapsulating packet. It may also be the word
729 <code>inherit</code>, in which case the ToS will be copied from
730 the inner packet if it is IPv4 or IPv6 (otherwise it will be
731 0). Note that the ECN fields are always inherited. Default is
735 <dt><code>ttl</code></dt>
736 <dd>Optional. The TTL to be set on the encapsulating packet.
737 It may also be the word <code>inherit</code>, in which case the
738 TTL will be copied from the inner packet if it is IPv4 or IPv6
739 (otherwise it will be the system default, typically 64).
740 Default is the system default TTL.</dd>
743 <dt><code>csum</code></dt>
744 <dd>Optional. Compute GRE checksums on outgoing packets.
745 Checksums present on incoming packets will be validated
746 regardless of this setting. Note that GRE checksums
747 impose a significant performance penalty as they cover the
748 entire packet. As the contents of the packet is typically
749 covered by L3 and L4 checksums, this additional checksum only
750 adds value for the GRE and encapsulated Ethernet headers.
751 Default is disabled, set to <code>true</code> to enable.</dd>
754 <dt><code>pmtud</code></dt>
755 <dd>Optional. Enable tunnel path MTU discovery. If enabled
756 ``ICMP destination unreachable - fragmentation'' needed
757 messages will be generated for IPv4 packets with the DF bit set
758 and IPv6 packets above the minimum MTU if the packet size
759 exceeds the path MTU minus the size of the tunnel headers. It
760 also forces the encapsulating packet DF bit to be set (it is
761 always set if the inner packet implies path MTU discovery).
762 Note that this option causes behavior that is typically
763 reserved for routers and therefore is not entirely in
764 compliance with the IEEE 802.1D specification for bridges.
765 Default is enabled, set to <code>false</code> to disable.</dd>
768 <dt><code>header_cache</code></dt>
769 <dd>Optional. Enable caching of tunnel headers and the output
770 path. This can lead to a significant performance increase
771 without changing behavior. In general it should not be
772 necessary to adjust this setting. However, the caching can
773 bypass certain components of the IP stack (such as IP tables)
774 and it may be useful to disable it if these features are
775 required or as a debugging measure. Default is enabled, set to
776 <code>false</code> to disable.</dd>
779 <dt><code>ipsec_gre</code></dt>
780 <dd>An Ethernet over RFC 2890 Generic Routing Encapsulation
781 over IPv4 IPsec tunnel. Each tunnel (including those of type
782 <code>gre</code>) must be uniquely identified by the
783 combination of <code>remote_ip</code> and
784 <code>local_ip</code>. Note that if two ports are defined
785 that are the same except one has an optional identifier and
786 the other does not, the more specific one is matched first.
787 An authentication method of <code>peer_cert</code> or
788 <code>psk</code> must be defined. The following options may
789 be specified in the <ref column="options"/> column:
791 <dt><code>remote_ip</code></dt>
792 <dd>Required. The tunnel endpoint.</dd>
795 <dt><code>local_ip</code></dt>
796 <dd>Optional. The destination IP that received packets must
797 match. Default is to match all addresses.</dd>
800 <dt><code>peer_cert</code></dt>
801 <dd>Required for certificate authentication. A string
802 containing the peer's certificate in PEM format.
803 Additionally the host's certificate must be specified
804 with the <code>certificate</code> option.</dd>
807 <dt><code>certificate</code></dt>
808 <dd>Required for certificate authentication. The name of a
809 PEM file containing a certificate that will be presented
810 to the peer during authentication.</dd>
813 <dt><code>private_key</code></dt>
814 <dd>Optional for certificate authentication. The name of
815 a PEM file containing the private key associated with
816 <code>certificate</code>. If <code>certificate</code>
817 contains the private key, this option may be omitted.</dd>
820 <dt><code>psk</code></dt>
821 <dd>Required for pre-shared key authentication. Specifies a
822 pre-shared key for authentication that must be identical on
823 both sides of the tunnel.</dd>
826 <dt><code>in_key</code></dt>
827 <dd>Optional. The GRE key that received packets must contain.
828 It may either be a 32-bit number (no key and a key of 0 are
829 treated as equivalent) or the word <code>flow</code>. If
830 <code>flow</code> is specified then any key will be accepted
831 and the key will be placed in the <code>tun_id</code> field
832 for matching in the flow table. The ovs-ofctl manual page
833 contains additional information about matching fields in
834 OpenFlow flows. Default is no key.</dd>
837 <dt><code>out_key</code></dt>
838 <dd>Optional. The GRE key to be set on outgoing packets. It may
839 either be a 32-bit number or the word <code>flow</code>. If
840 <code>flow</code> is specified then the key may be set using
841 the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0
842 is used in the absence of an action). The ovs-ofctl manual
843 page contains additional information about the Nicira OpenFlow
844 vendor extensions. Default is no key.</dd>
847 <dt><code>key</code></dt>
848 <dd>Optional. Shorthand to set <code>in_key</code> and
849 <code>out_key</code> at the same time.</dd>
852 <dt><code>tos</code></dt>
853 <dd>Optional. The value of the ToS bits to be set on the
854 encapsulating packet. It may also be the word
855 <code>inherit</code>, in which case the ToS will be copied from
856 the inner packet if it is IPv4 or IPv6 (otherwise it will be
857 0). Note that the ECN fields are always inherited. Default is
861 <dt><code>ttl</code></dt>
862 <dd>Optional. The TTL to be set on the encapsulating packet.
863 It may also be the word <code>inherit</code>, in which case the
864 TTL will be copied from the inner packet if it is IPv4 or IPv6
865 (otherwise it will be the system default, typically 64).
866 Default is the system default TTL.</dd>
869 <dt><code>csum</code></dt>
870 <dd>Optional. Compute GRE checksums on outgoing packets.
871 Checksums present on incoming packets will be validated
872 regardless of this setting. Note that GRE checksums
873 impose a significant performance penalty as they cover the
874 entire packet. As the contents of the packet is typically
875 covered by L3 and L4 checksums, this additional checksum only
876 adds value for the GRE and encapsulated Ethernet headers.
877 Default is disabled, set to <code>true</code> to enable.</dd>
880 <dt><code>pmtud</code></dt>
881 <dd>Optional. Enable tunnel path MTU discovery. If enabled
882 ``ICMP destination unreachable - fragmentation'' needed
883 messages will be generated for IPv4 packets with the DF bit set
884 and IPv6 packets above the minimum MTU if the packet size
885 exceeds the path MTU minus the size of the tunnel headers. It
886 also forces the encapsulating packet DF bit to be set (it is
887 always set if the inner packet implies path MTU discovery).
888 Note that this option causes behavior that is typically
889 reserved for routers and therefore is not entirely in
890 compliance with the IEEE 802.1D specification for bridges.
891 Default is enabled, set to <code>false</code> to disable.</dd>
894 <dt><code>capwap</code></dt>
895 <dd>Ethernet tunneling over the UDP transport portion of CAPWAP
896 (RFC 5415). This allows interoperability with certain switches
897 where GRE is not available. Note that only the tunneling component
898 of the protocol is implemented. Due to the non-standard use of
899 CAPWAP, UDP ports 58881 and 58882 are used as the source and
900 destinations ports respectivedly. Each tunnel must be uniquely
901 identified by the combination of <code>remote_ip</code> and
902 <code>local_ip</code>. If two ports are defined that are the same
903 except one includes <code>local_ip</code> and the other does not,
904 the more specific one is matched first. CAPWAP support is not
905 available on all platforms. Currently it is only supported in the
906 Linux kernel module with kernel versions >= 2.6.25. The following
907 options may be specified in the <ref column="options"/> column:
909 <dt><code>remote_ip</code></dt>
910 <dd>Required. The tunnel endpoint.</dd>
913 <dt><code>local_ip</code></dt>
914 <dd>Optional. The destination IP that received packets must
915 match. Default is to match all addresses.</dd>
918 <dt><code>tos</code></dt>
919 <dd>Optional. The value of the ToS bits to be set on the
920 encapsulating packet. It may also be the word
921 <code>inherit</code>, in which case the ToS will be copied from
922 the inner packet if it is IPv4 or IPv6 (otherwise it will be
923 0). Note that the ECN fields are always inherited. Default is
927 <dt><code>ttl</code></dt>
928 <dd>Optional. The TTL to be set on the encapsulating packet.
929 It may also be the word <code>inherit</code>, in which case the
930 TTL will be copied from the inner packet if it is IPv4 or IPv6
931 (otherwise it will be the system default, typically 64).
932 Default is the system default TTL.</dd>
935 <dt><code>pmtud</code></dt>
936 <dd>Optional. Enable tunnel path MTU discovery. If enabled
937 ``ICMP destination unreachable - fragmentation'' needed
938 messages will be generated for IPv4 packets with the DF bit set
939 and IPv6 packets above the minimum MTU if the packet size
940 exceeds the path MTU minus the size of the tunnel headers. It
941 also forces the encapsulating packet DF bit to be set (it is
942 always set if the inner packet implies path MTU discovery).
943 Note that this option causes behavior that is typically
944 reserved for routers and therefore is not entirely in
945 compliance with the IEEE 802.1D specification for bridges.
946 Default is enabled, set to <code>false</code> to disable.</dd>
949 <dt><code>header_cache</code></dt>
950 <dd>Optional. Enable caching of tunnel headers and the output
951 path. This can lead to a significant performance increase
952 without changing behavior. In general it should not be
953 necessary to adjust this setting. However, the caching can
954 bypass certain components of the IP stack (such as IP tables)
955 and it may be useful to disable it if these features are
956 required or as a debugging measure. Default is enabled, set to
957 <code>false</code> to disable.</dd>
960 <dt><code>patch</code></dt>
963 A pair of virtual devices that act as a patch cable. The <ref
964 column="options"/> column must have the following key-value pair:
967 <dt><code>peer</code></dt>
969 The <ref column="name"/> of the <ref table="Interface"/> for
970 the other side of the patch. The named <ref
971 table="Interface"/>'s own <code>peer</code> option must specify
972 this <ref table="Interface"/>'s name. That is, the two patch
973 interfaces must have reversed <ref column="name"/> and
974 <code>peer</code> values.
981 <column name="options">
982 Configuration options whose interpretation varies based on
983 <ref column="type"/>.
987 <group title="Interface Status">
989 Status information about interfaces attached to bridges, updated every
990 5 seconds. Not all interfaces have all of these properties; virtual
991 interfaces don't have a link speed, for example. Non-applicable
992 columns will have empty values.
994 <column name="admin_state">
996 The administrative state of the physical network link.
1000 <column name="link_state">
1002 The observed state of the physical network link;
1003 i.e. whether a carrier is detected by the interface.
1007 <column name="link_speed">
1009 The negotiated speed of the physical network link.
1010 Valid values are positive integers greater than 0.
1014 <column name="duplex">
1016 The duplex mode of the physical network link.
1022 The MTU (maximum transmission unit); i.e. the largest
1023 amount of data that can fit into a single Ethernet frame.
1024 The standard Ethernet MTU is 1500 bytes. Some physical media
1025 and many kinds of virtual interfaces can be configured with
1030 <column name="status">
1032 Key-value pairs that report port status. Supported status
1033 values are <code>type</code>-dependent; some interfaces may not have
1034 a valid <code>driver_name</code>, for example.
1036 <p>The currently defined key-value pairs are:</p>
1038 <dt><code>driver_name</code></dt>
1039 <dd>The name of the device driver controlling the network
1043 <dt><code>driver_version</code></dt>
1044 <dd>The version string of the device driver controlling the
1045 network adapter.</dd>
1048 <dt><code>firmware_version</code></dt>
1049 <dd>The version string of the network adapter's firmware, if
1053 <dt><code>source_ip</code></dt>
1054 <dd>The source IP address used for an IPv4 tunnel end-point,
1055 such as <code>gre</code> or <code>capwap</code>.</dd>
1058 <dt><code>tunnel_egress_iface</code></dt>
1059 <dd>Egress interface for tunnels. Currently only relevant for GRE
1060 and CAPWAP tunnels. On Linux systems, this column will show
1061 the name of the interface which is responsible for routing
1062 traffic destined for the configured <code>remote_ip</code>.
1063 This could be an internal interface such as a bridge port.</dd>
1066 <dt><code>tunnel_egress_iface_carrier</code></dt>
1067 <dd>Whether a carrier is detected on <ref
1068 column="tunnel_egress_iface"/>. Valid values are <code>down</code>
1069 and <code>up</code>.</dd>
1074 <group title="Ingress Policing">
1076 These settings control ingress policing for packets received on this
1077 interface. On a physical interface, this limits the rate at which
1078 traffic is allowed into the system from the outside; on a virtual
1079 interface (one connected to a virtual machine), this limits the rate at
1080 which the VM is able to transmit.
1083 Policing is a simple form of quality-of-service that simply drops
1084 packets received in excess of the configured rate. Due to its
1085 simplicity, policing is usually less accurate and less effective than
1086 egress QoS (which is configured using the <ref table="QoS"/> and <ref
1087 table="Queue"/> tables).
1090 Policing is currently implemented only on Linux. The Linux
1091 implementation uses a simple ``token bucket'' approach:
1095 The size of the bucket corresponds to <ref
1096 column="ingress_policing_burst"/>. Initially the bucket is full.
1099 Whenever a packet is received, its size (converted to tokens) is
1100 compared to the number of tokens currently in the bucket. If the
1101 required number of tokens are available, they are removed and the
1102 packet is forwarded. Otherwise, the packet is dropped.
1105 Whenever it is not full, the bucket is refilled with tokens at the
1106 rate specified by <ref column="ingress_policing_rate"/>.
1110 Policing interacts badly with some network protocols, and especially
1111 with fragmented IP packets. Suppose that there is enough network
1112 activity to keep the bucket nearly empty all the time. Then this token
1113 bucket algorithm will forward a single packet every so often, with the
1114 period depending on packet size and on the configured rate. All of the
1115 fragments of an IP packets are normally transmitted back-to-back, as a
1116 group. In such a situation, therefore, only one of these fragments
1117 will be forwarded and the rest will be dropped. IP does not provide
1118 any way for the intended recipient to ask for only the remaining
1119 fragments. In such a case there are two likely possibilities for what
1120 will happen next: either all of the fragments will eventually be
1121 retransmitted (as TCP will do), in which case the same problem will
1122 recur, or the sender will not realize that its packet has been dropped
1123 and data will simply be lost (as some UDP-based protocols will do).
1124 Either way, it is possible that no forward progress will ever occur.
1126 <column name="ingress_policing_rate">
1128 Maximum rate for data received on this interface, in kbps. Data
1129 received faster than this rate is dropped. Set to <code>0</code>
1130 (the default) to disable policing.
1134 <column name="ingress_policing_burst">
1135 <p>Maximum burst size for data received on this interface, in kb. The
1136 default burst size if set to <code>0</code> is 1000 kb. This value
1137 has no effect if <ref column="ingress_policing_rate"/>
1138 is <code>0</code>.</p>
1140 Specifying a larger burst size lets the algorithm be more forgiving,
1141 which is important for protocols like TCP that react severely to
1142 dropped packets. The burst size should be at least the size of the
1143 interface's MTU. Specifying a value that is numerically at least as
1144 large as 10% of <ref column="ingress_policing_rate"/> helps TCP come
1145 closer to achieving the full rate.
1150 <group title="Other Features">
1152 <column name="monitor">
1153 Connectivity monitor configuration for this interface.
1156 <column name="external_ids">
1157 Key-value pairs for use by external frameworks that integrate
1158 with Open vSwitch, rather than by Open vSwitch itself. System
1159 integrators should either use the Open vSwitch development
1160 mailing list to coordinate on common key-value definitions, or
1161 choose key names that are likely to be unique. The currently
1162 defined common key-value pairs are:
1164 <dt><code>attached-mac</code></dt>
1166 The MAC address programmed into the ``virtual hardware'' for this
1167 interface, in the form
1168 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>.
1169 For Citrix XenServer, this is the value of the <code>MAC</code>
1170 field in the VIF record for this interface.</dd>
1171 <dt><code>iface-id</code></dt>
1172 <dd>A system-unique identifier for the interface. On XenServer,
1173 this will commonly be the same as <code>xs-vif-uuid</code>.</dd>
1176 Additionally the following key-value pairs specifically
1177 apply to an interface that represents a virtual Ethernet interface
1178 connected to a virtual machine. These key-value pairs should not be
1179 present for other types of interfaces. Keys whose names end
1180 in <code>-uuid</code> have values that uniquely identify the entity
1181 in question. For a Citrix XenServer hypervisor, these values are
1182 UUIDs in RFC 4122 format. Other hypervisors may use other
1185 <p>The currently defined key-value pairs for XenServer are:</p>
1187 <dt><code>xs-vif-uuid</code></dt>
1188 <dd>The virtual interface associated with this interface.</dd>
1189 <dt><code>xs-network-uuid</code></dt>
1190 <dd>The virtual network to which this interface is attached.</dd>
1191 <dt><code>xs-vm-uuid</code></dt>
1192 <dd>The VM to which this interface belongs.</dd>
1196 <column name="other_config">
1197 Key-value pairs for rarely used interface features. Currently,
1198 there are none defined.
1201 <column name="statistics">
1203 Key-value pairs that report interface statistics. The current
1204 implementation updates these counters periodically. In the future,
1205 we plan to, instead, update them when an interface is created, when
1206 they are queried (e.g. using an OVSDB <code>select</code> operation),
1207 and just before an interface is deleted due to virtual interface
1208 hot-unplug or VM shutdown, and perhaps at other times, but not on any
1209 regular periodic basis.</p>
1211 The currently defined key-value pairs are listed below. These are
1212 the same statistics reported by OpenFlow in its <code>struct
1213 ofp_port_stats</code> structure. If an interface does not support a
1214 given statistic, then that pair is omitted.</p>
1217 Successful transmit and receive counters:
1219 <dt><code>rx_packets</code></dt>
1220 <dd>Number of received packets.</dd>
1221 <dt><code>rx_bytes</code></dt>
1222 <dd>Number of received bytes.</dd>
1223 <dt><code>tx_packets</code></dt>
1224 <dd>Number of transmitted packets.</dd>
1225 <dt><code>tx_bytes</code></dt>
1226 <dd>Number of transmitted bytes.</dd>
1232 <dt><code>rx_dropped</code></dt>
1233 <dd>Number of packets dropped by RX.</dd>
1234 <dt><code>rx_frame_err</code></dt>
1235 <dd>Number of frame alignment errors.</dd>
1236 <dt><code>rx_over_err</code></dt>
1237 <dd>Number of packets with RX overrun.</dd>
1238 <dt><code>rx_crc_err</code></dt>
1239 <dd>Number of CRC errors.</dd>
1240 <dt><code>rx_errors</code></dt>
1242 Total number of receive errors, greater than or equal
1243 to the sum of the above.
1250 <dt><code>tx_dropped</code></dt>
1251 <dd>Number of packets dropped by TX.</dd>
1252 <dt><code>collisions</code></dt>
1253 <dd>Number of collisions.</dd>
1254 <dt><code>tx_errors</code></dt>
1256 Total number of transmit errors, greater
1257 than or equal to the sum of the above.
1266 <table name="QoS" title="Quality of Service configuration">
1267 <p>Quality of Service (QoS) configuration for each Port that
1270 <column name="type">
1271 <p>The type of QoS to implement. The <ref table="Open_vSwitch"
1272 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
1273 identifies the types that a switch actually supports. The currently
1274 defined types are listed below:</p>
1276 <dt><code>linux-htb</code></dt>
1278 Linux ``hierarchy token bucket'' classifier. See tc-htb(8) (also at
1279 <code>http://linux.die.net/man/8/tc-htb</code>) and the HTB manual
1280 (<code>http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm</code>)
1281 for information on how this classifier works and how to configure it.
1285 <dt><code>linux-hfsc</code></dt>
1287 Linux "Hierarchical Fair Service Curve" classifier.
1288 See <code>http://linux-ip.net/articles/hfsc.en/</code> for
1289 information on how this classifier works.
1294 <column name="queues">
1295 <p>A map from queue numbers to <ref table="Queue"/> records. The
1296 supported range of queue numbers depend on <ref column="type"/>. The
1297 queue numbers are the same as the <code>queue_id</code> used in
1298 OpenFlow in <code>struct ofp_action_enqueue</code> and other
1299 structures. Queue 0 is used by OpenFlow output actions that do not
1300 specify a specific queue.</p>
1303 <column name="other_config">
1304 <p>Key-value pairs for configuring QoS features that depend on
1305 <ref column="type"/>.</p>
1306 <p>The <code>linux-htb</code> and <code>linux-hfsc</code> classes support
1307 the following key-value pairs:</p>
1309 <dt><code>max-rate</code></dt>
1310 <dd>Maximum rate shared by all queued traffic, in bit/s.
1311 Optional. If not specified, for physical interfaces, the
1312 default is the link rate. For other interfaces or if the
1313 link rate cannot be determined, the default is currently 100
1318 <column name="external_ids">
1319 Key-value pairs for use by external frameworks that integrate with Open
1320 vSwitch, rather than by Open vSwitch itself. System integrators should
1321 either use the Open vSwitch development mailing list to coordinate on
1322 common key-value definitions, or choose key names that are likely to be
1323 unique. No common key-value pairs are currently defined.
1327 <table name="Queue" title="QoS output queue.">
1328 <p>A configuration for a port output queue, used in configuring Quality of
1329 Service (QoS) features. May be referenced by <ref column="queues"
1330 table="QoS"/> column in <ref table="QoS"/> table.</p>
1332 <column name="other_config">
1333 <p>Key-value pairs for configuring the output queue. The supported
1334 key-value pairs and their meanings depend on the <ref column="type"/>
1335 of the <ref column="QoS"/> records that reference this row.</p>
1336 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1337 column="type"/> of <code>min-rate</code> are:</p>
1339 <dt><code>min-rate</code></dt>
1340 <dd>Minimum guaranteed bandwidth, in bit/s. Required. The
1341 floor value is 1500 bytes/s (12,000 bit/s).</dd>
1343 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1344 column="type"/> of <code>linux-htb</code> are:</p>
1346 <dt><code>min-rate</code></dt>
1347 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1348 <dt><code>max-rate</code></dt>
1349 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1350 queue's rate will not be allowed to exceed the specified value, even
1351 if excess bandwidth is available. If unspecified, defaults to no
1353 <dt><code>burst</code></dt>
1354 <dd>Burst size, in bits. This is the maximum amount of ``credits''
1355 that a queue can accumulate while it is idle. Optional. Details of
1356 the <code>linux-htb</code> implementation require a minimum burst
1357 size, so a too-small <code>burst</code> will be silently
1359 <dt><code>priority</code></dt>
1360 <dd>A nonnegative 32-bit integer. Defaults to 0 if
1361 unspecified. A queue with a smaller <code>priority</code>
1362 will receive all the excess bandwidth that it can use before
1363 a queue with a larger value receives any. Specific priority
1364 values are unimportant; only relative ordering matters.</dd>
1366 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1367 column="type"/> of <code>linux-hfsc</code> are:</p>
1369 <dt><code>min-rate</code></dt>
1370 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1371 <dt><code>max-rate</code></dt>
1372 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1373 queue's rate will not be allowed to exceed the specified value, even
1374 if excess bandwidth is available. If unspecified, defaults to no
1379 <column name="external_ids">
1380 Key-value pairs for use by external frameworks that integrate with Open
1381 vSwitch, rather than by Open vSwitch itself. System integrators should
1382 either use the Open vSwitch development mailing list to coordinate on
1383 common key-value definitions, or choose key names that are likely to be
1384 unique. No common key-value pairs are currently defined.
1388 <table name="Monitor" title="Connectivity Monitor configuration">
1390 A <ref table="Monitor"/> attaches to an <ref table="Interface"/> to
1391 implement 802.1ag Connectivity Fault Management (CFM). CFM allows a
1392 group of Maintenance Points (MPs) called a Maintenance Association (MA)
1393 to detect connectivity problems with each other. MPs within a MA should
1394 have complete and exclusive interconnectivity. This is verified by
1395 occasionally broadcasting Continuity Check Messages (CCMs) at a
1396 configurable transmission interval. A <ref table="Monitor"/> is
1397 responsible for collecting data about other MPs in its MA and
1401 <group title="Monitor Configuration">
1402 <column name="mpid">
1403 A Maintenance Point ID (MPID) uniquely identifies each endpoint within
1404 a Maintenance Association (see <ref column="ma_name"/>). The MPID is
1405 used to identify this <ref table="Monitor"/> to other endpoints in the
1409 <column name="remote_mps">
1410 A set of <ref table="Maintenance_Points"/> which this
1411 <ref table="Monitor"/> should have connectivity to. If this
1412 <ref table="Monitor"/> does not have connectivity to any MPs in this
1413 set, or has connectivity to any MPs not in this set, a fault is
1417 <column name="ma_name">
1418 A Maintenance Association (MA) name pairs with a Maintenance Domain
1419 (MD) name to uniquely identify a MA. A MA is a group of endpoints who
1420 have complete and exclusive interconnectivity. Defaults to
1421 <code>ovs</code> if unset.
1424 <column name="md_name">
1425 A Maintenance Domain name pairs with a Maintenance Association name to
1426 uniquely identify a MA. Defaults to <code>ovs</code> if unset.
1429 <column name="interval">
1430 The transmission interval of CCMs in milliseconds. Three missed CCMs
1431 indicate a connectivity fault. Defaults to 1000ms.
1435 <group title="Monitor Status">
1436 <column name="unexpected_remote_mpids">
1437 A set of MPIDs representing MPs to which this <ref table="Monitor"/>
1438 has detected connectivity that are not in the
1439 <ref column="remote_mps"/> set. This <ref table="Monitor"/> should not
1440 have connectivity to any MPs not listed in <ref column="remote_mps"/>.
1441 Thus, if this set is non-empty a fault is indicated.
1444 <column name="unexpected_remote_maids">
1445 A set of MAIDs representing foreign Maintenance Associations (MAs)
1446 which this <ref table="Monitor"/> has detected connectivity to. A
1447 <ref table="Monitor"/> should not have connectivity to a Maintenance
1448 Association other than its own. Thus, if this set is non-empty a fault
1452 <column name="fault">
1453 Indicates a Connectivity Fault caused by a configuration error, a down
1454 remote MP, or unexpected connectivity to a remote MAID or remote MP.
1459 <table name="Maintenance_Point" title="Maintenance Point configuration">
1461 A <ref table="Maintenance_Point"/> represents a MP which a
1462 <ref table="Monitor"/> has or should have connectivity to.
1465 <group title="Maintenance_Point Configuration">
1466 <column name="mpid">
1467 A Maintenance Point ID (MPID) uniquely identifies each endpoint within
1468 a Maintenance Association. All MPs within a MA should have a unique
1473 <group title="Maintenance_Point Status">
1474 <column name="fault">
1475 Indicates a connectivity fault.
1480 <table name="Mirror" title="Port mirroring (SPAN/RSPAN).">
1481 <p>A port mirror within a <ref table="Bridge"/>.</p>
1482 <p>A port mirror configures a bridge to send selected frames to special
1483 ``mirrored'' ports, in addition to their normal destinations. Mirroring
1484 traffic may also be referred to as SPAN or RSPAN, depending on the
1485 mechanism used for delivery.</p>
1487 <column name="name">
1488 Arbitrary identifier for the <ref table="Mirror"/>.
1491 <group title="Selecting Packets for Mirroring">
1492 <column name="select_all">
1493 If true, every packet arriving or departing on any port is
1494 selected for mirroring.
1497 <column name="select_dst_port">
1498 Ports on which departing packets are selected for mirroring.
1501 <column name="select_src_port">
1502 Ports on which arriving packets are selected for mirroring.
1505 <column name="select_vlan">
1506 VLANs on which packets are selected for mirroring. An empty set
1507 selects packets on all VLANs.
1511 <group title="Mirroring Destination Configuration">
1512 <column name="output_port">
1513 <p>Output port for selected packets, if nonempty. Mutually exclusive
1514 with <ref column="output_vlan"/>.</p>
1515 <p>Specifying a port for mirror output reserves that port exclusively
1516 for mirroring. No frames other than those selected for mirroring
1517 will be forwarded to the port, and any frames received on the port
1518 will be discarded.</p>
1519 <p>This type of mirroring is sometimes called SPAN.</p>
1522 <column name="output_vlan">
1523 <p>Output VLAN for selected packets, if nonempty. Mutually exclusive
1524 with <ref column="output_port"/>.</p>
1525 <p>The frames will be sent out all ports that trunk
1526 <ref column="output_vlan"/>, as well as any ports with implicit VLAN
1527 <ref column="output_vlan"/>. When a mirrored frame is sent out a
1528 trunk port, the frame's VLAN tag will be set to
1529 <ref column="output_vlan"/>, replacing any existing tag; when it is
1530 sent out an implicit VLAN port, the frame will not be tagged. This
1531 type of mirroring is sometimes called RSPAN.</p>
1532 <p><em>Please note:</em> Mirroring to a VLAN can disrupt a network that
1533 contains unmanaged switches. Consider an unmanaged physical switch
1534 with two ports: port 1, connected to an end host, and port 2,
1535 connected to an Open vSwitch configured to mirror received packets
1536 into VLAN 123 on port 2. Suppose that the end host sends a packet on
1537 port 1 that the physical switch forwards to port 2. The Open vSwitch
1538 forwards this packet to its destination and then reflects it back on
1539 port 2 in VLAN 123. This reflected packet causes the unmanaged
1540 physical switch to replace the MAC learning table entry, which
1541 correctly pointed to port 1, with one that incorrectly points to port
1542 2. Afterward, the physical switch will direct packets destined for
1543 the end host to the Open vSwitch on port 2, instead of to the end
1544 host on port 1, disrupting connectivity. If mirroring to a VLAN is
1545 desired in this scenario, then the physical switch must be replaced
1546 by one that learns Ethernet addresses on a per-VLAN basis. In
1547 addition, learning should be disabled on the VLAN containing mirrored
1548 traffic. If this is not done then intermediate switches will learn
1549 the MAC address of each end host from the mirrored traffic. If
1550 packets being sent to that end host are also mirrored, then they will
1551 be dropped since the switch will attempt to send them out the input
1552 port. Disabling learning for the VLAN will cause the switch to
1553 correctly send the packet out all ports configured for that VLAN. If
1554 Open vSwitch is being used as an intermediate switch, learning can be
1555 disabled by adding the mirrored VLAN to <ref column="flood_vlans"/>
1556 in the appropriate <ref table="Bridge"/> table or tables.</p>
1560 <group title="Other Features">
1561 <column name="external_ids">
1562 Key-value pairs for use by external frameworks that integrate with Open
1563 vSwitch, rather than by Open vSwitch itself. System integrators should
1564 either use the Open vSwitch development mailing list to coordinate on
1565 common key-value definitions, or choose key names that are likely to be
1566 unique. No common key-value pairs are currently defined.
1571 <table name="Controller" title="OpenFlow controller configuration.">
1572 <p>An OpenFlow controller.</p>
1575 Open vSwitch supports two kinds of OpenFlow controllers:
1579 <dt>Primary controllers</dt>
1582 This is the kind of controller envisioned by the OpenFlow 1.0
1583 specification. Usually, a primary controller implements a network
1584 policy by taking charge of the switch's flow table.
1588 Open vSwitch initiates and maintains persistent connections to
1589 primary controllers, retrying the connection each time it fails or
1590 drops. The <ref table="Bridge" column="fail_mode"/> column in the
1591 <ref table="Bridge"/> table applies to primary controllers.
1595 Open vSwitch permits a bridge to have any number of primary
1596 controllers. When multiple controllers are configured, Open
1597 vSwitch connects to all of them simultaneously. Because
1598 OpenFlow 1.0 does not specify how multiple controllers
1599 coordinate in interacting with a single switch, more than
1600 one primary controller should be specified only if the
1601 controllers are themselves designed to coordinate with each
1602 other. (The Nicira-defined <code>NXT_ROLE</code> OpenFlow
1603 vendor extension may be useful for this.)
1606 <dt>Service controllers</dt>
1609 These kinds of OpenFlow controller connections are intended for
1610 occasional support and maintenance use, e.g. with
1611 <code>ovs-ofctl</code>. Usually a service controller connects only
1612 briefly to inspect or modify some of a switch's state.
1616 Open vSwitch listens for incoming connections from service
1617 controllers. The service controllers initiate and, if necessary,
1618 maintain the connections from their end. The <ref table="Bridge"
1619 column="fail_mode"/> column in the <ref table="Bridge"/> table does
1620 not apply to service controllers.
1624 Open vSwitch supports configuring any number of service controllers.
1630 The <ref column="target"/> determines the type of controller.
1633 <group title="Core Features">
1634 <column name="target">
1635 <p>Connection method for controller.</p>
1637 The following connection methods are currently supported for primary
1641 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1643 <p>The specified SSL <var>port</var> (default: 6633) on the host at
1644 the given <var>ip</var>, which must be expressed as an IP address
1645 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1646 column in the <ref table="Open_vSwitch"/> table must point to a
1647 valid SSL configuration when this form is used.</p>
1648 <p>SSL support is an optional feature that is not always built as
1649 part of Open vSwitch.</p>
1651 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1652 <dd>The specified TCP <var>port</var> (default: 6633) on the host at
1653 the given <var>ip</var>, which must be expressed as an IP address
1654 (not a DNS name).</dd>
1655 <dt><code>discover</code></dt>
1657 <p>Enables controller discovery.</p>
1658 <p>In controller discovery mode, Open vSwitch broadcasts a DHCP
1659 request with vendor class identifier <code>OpenFlow</code> across
1660 all of the bridge's network devices. It will accept any valid
1661 DHCP reply that has the same vendor class identifier and includes
1662 a vendor-specific option with code 1 whose contents are a string
1663 specifying the location of the controller in the same format as
1664 <ref column="target"/>.</p>
1665 <p>The DHCP reply may also, optionally, include a vendor-specific
1666 option with code 2 whose contents are a string specifying the URI
1667 to the base of the OpenFlow PKI
1668 (e.g. <code>http://192.168.0.1/openflow/pki</code>). This URI is
1669 used only for bootstrapping the OpenFlow PKI at initial switch
1670 setup; <code>ovs-vswitchd</code> does not use it at all.</p>
1674 The following connection methods are currently supported for service
1678 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1681 Listens for SSL connections on the specified TCP <var>port</var>
1682 (default: 6633). If <var>ip</var>, which must be expressed as an
1683 IP address (not a DNS name), is specified, then connections are
1684 restricted to the specified local IP address.
1687 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1688 table="Open_vSwitch"/> table must point to a valid SSL
1689 configuration when this form is used.
1691 <p>SSL support is an optional feature that is not always built as
1692 part of Open vSwitch.</p>
1694 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1696 Listens for connections on the specified TCP <var>port</var>
1697 (default: 6633). If <var>ip</var>, which must be expressed as an
1698 IP address (not a DNS name), is specified, then connections are
1699 restricted to the specified local IP address.
1702 <p>When multiple controllers are configured for a single bridge, the
1703 <ref column="target"/> values must be unique. Duplicate
1704 <ref column="target"/> values yield unspecified results.</p>
1707 <column name="connection_mode">
1708 <p>If it is specified, this setting must be one of the following
1709 strings that describes how Open vSwitch contacts this OpenFlow
1710 controller over the network:</p>
1713 <dt><code>in-band</code></dt>
1714 <dd>In this mode, this controller's OpenFlow traffic travels over the
1715 bridge associated with the controller. With this setting, Open
1716 vSwitch allows traffic to and from the controller regardless of the
1717 contents of the OpenFlow flow table. (Otherwise, Open vSwitch
1718 would never be able to connect to the controller, because it did
1719 not have a flow to enable it.) This is the most common connection
1720 mode because it is not necessary to maintain two independent
1722 <dt><code>out-of-band</code></dt>
1723 <dd>In this mode, OpenFlow traffic uses a control network separate
1724 from the bridge associated with this controller, that is, the
1725 bridge does not use any of its own network devices to communicate
1726 with the controller. The control network must be configured
1727 separately, before or after <code>ovs-vswitchd</code> is started.
1731 <p>If not specified, the default is implementation-specific. If
1732 <ref column="target"/> is <code>discover</code>, the connection mode
1733 is always treated as <code>in-band</code> regardless of the actual
1738 <group title="Controller Failure Detection and Handling">
1739 <column name="max_backoff">
1740 Maximum number of milliseconds to wait between connection attempts.
1741 Default is implementation-specific.
1744 <column name="inactivity_probe">
1745 Maximum number of milliseconds of idle time on connection to
1746 controller before sending an inactivity probe message. If Open
1747 vSwitch does not communicate with the controller for the specified
1748 number of seconds, it will send a probe. If a response is not
1749 received for the same additional amount of time, Open vSwitch
1750 assumes the connection has been broken and attempts to reconnect.
1751 Default is implementation-specific.
1755 <group title="OpenFlow Rate Limiting">
1756 <column name="controller_rate_limit">
1757 <p>The maximum rate at which packets in unknown flows will be
1758 forwarded to the OpenFlow controller, in packets per second. This
1759 feature prevents a single bridge from overwhelming the controller.
1760 If not specified, the default is implementation-specific.</p>
1761 <p>In addition, when a high rate triggers rate-limiting, Open
1762 vSwitch queues controller packets for each port and transmits
1763 them to the controller at the configured rate. The number of
1764 queued packets is limited by
1765 the <ref column="controller_burst_limit"/> value. The packet
1766 queue is shared fairly among the ports on a bridge.</p><p>Open
1767 vSwitch maintains two such packet rate-limiters per bridge.
1768 One of these applies to packets sent up to the controller
1769 because they do not correspond to any flow. The other applies
1770 to packets sent up to the controller by request through flow
1771 actions. When both rate-limiters are filled with packets, the
1772 actual rate that packets are sent to the controller is up to
1773 twice the specified rate.</p>
1776 <column name="controller_burst_limit">
1777 In conjunction with <ref column="controller_rate_limit"/>,
1778 the maximum number of unused packet credits that the bridge will
1779 allow to accumulate, in packets. If not specified, the default
1780 is implementation-specific.
1784 <group title="Additional Discovery Configuration">
1785 <p>These values are considered only when <ref column="target"/>
1786 is <code>discover</code>.</p>
1788 <column name="discover_accept_regex">
1790 extended regular expression against which the discovered controller
1791 location is validated. The regular expression is implicitly
1792 anchored at the beginning of the controller location string, as
1793 if it begins with <code>^</code>. If not specified, the default
1794 is implementation-specific.
1797 <column name="discover_update_resolv_conf">
1798 Whether to update <code>/etc/resolv.conf</code> when the
1799 controller is discovered. If not specified, the default
1800 is implementation-specific. Open vSwitch will only modify
1801 <code>/etc/resolv.conf</code> if the DHCP response that it receives
1802 specifies one or more DNS servers.
1806 <group title="Additional In-Band Configuration">
1807 <p>These values are considered only in in-band control mode (see
1808 <ref column="connection_mode"/>) and only when <ref column="target"/>
1809 is not <code>discover</code>. (For controller discovery, the network
1810 configuration obtained via DHCP is used instead.)</p>
1812 <p>When multiple controllers are configured on a single bridge, there
1813 should be only one set of unique values in these columns. If different
1814 values are set for these columns in different controllers, the effect
1817 <column name="local_ip">
1818 The IP address to configure on the local port,
1819 e.g. <code>192.168.0.123</code>. If this value is unset, then
1820 <ref column="local_netmask"/> and <ref column="local_gateway"/> are
1824 <column name="local_netmask">
1825 The IP netmask to configure on the local port,
1826 e.g. <code>255.255.255.0</code>. If <ref column="local_ip"/> is set
1827 but this value is unset, then the default is chosen based on whether
1828 the IP address is class A, B, or C.
1831 <column name="local_gateway">
1832 The IP address of the gateway to configure on the local port, as a
1833 string, e.g. <code>192.168.0.1</code>. Leave this column unset if
1834 this network has no gateway.
1838 <group title="Other Features">
1839 <column name="external_ids">
1840 Key-value pairs for use by external frameworks that integrate with Open
1841 vSwitch, rather than by Open vSwitch itself. System integrators should
1842 either use the Open vSwitch development mailing list to coordinate on
1843 common key-value definitions, or choose key names that are likely to be
1844 unique. No common key-value pairs are currently defined.
1849 <table name="Manager" title="OVSDB management connection.">
1851 Configuration for a database connection to an Open vSwitch database
1856 This table primarily configures the Open vSwitch database
1857 (<code>ovsdb-server</code>), not the Open vSwitch switch
1858 (<code>ovs-vswitchd</code>). The switch does read the table to determine
1859 what connections should be treated as in-band.
1863 The Open vSwitch database server can initiate and maintain active
1864 connections to remote clients. It can also listen for database
1868 <group title="Core Features">
1869 <column name="target">
1870 <p>Connection method for managers.</p>
1872 The following connection methods are currently supported:
1875 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1878 The specified SSL <var>port</var> (default: 6632) on the host at
1879 the given <var>ip</var>, which must be expressed as an IP address
1880 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1881 column in the <ref table="Open_vSwitch"/> table must point to a
1882 valid SSL configuration when this form is used.
1885 SSL support is an optional feature that is not always built as
1886 part of Open vSwitch.
1890 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1892 The specified TCP <var>port</var> (default: 6632) on the host at
1893 the given <var>ip</var>, which must be expressed as an IP address
1896 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1899 Listens for SSL connections on the specified TCP <var>port</var>
1900 (default: 6632). If <var>ip</var>, which must be expressed as an
1901 IP address (not a DNS name), is specified, then connections are
1902 restricted to the specified local IP address.
1905 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1906 table="Open_vSwitch"/> table must point to a valid SSL
1907 configuration when this form is used.
1910 SSL support is an optional feature that is not always built as
1911 part of Open vSwitch.
1914 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1916 Listens for connections on the specified TCP <var>port</var>
1917 (default: 6632). If <var>ip</var>, which must be expressed as an
1918 IP address (not a DNS name), is specified, then connections are
1919 restricted to the specified local IP address.
1922 <p>When multiple managers are configured, the <ref column="target"/>
1923 values must be unique. Duplicate <ref column="target"/> values yield
1924 unspecified results.</p>
1927 <column name="connection_mode">
1929 If it is specified, this setting must be one of the following strings
1930 that describes how Open vSwitch contacts this OVSDB client over the
1935 <dt><code>in-band</code></dt>
1937 In this mode, this connection's traffic travels over a bridge
1938 managed by Open vSwitch. With this setting, Open vSwitch allows
1939 traffic to and from the client regardless of the contents of the
1940 OpenFlow flow table. (Otherwise, Open vSwitch would never be able
1941 to connect to the client, because it did not have a flow to enable
1942 it.) This is the most common connection mode because it is not
1943 necessary to maintain two independent networks.
1945 <dt><code>out-of-band</code></dt>
1947 In this mode, the client's traffic uses a control network separate
1948 from that managed by Open vSwitch, that is, Open vSwitch does not
1949 use any of its own network devices to communicate with the client.
1950 The control network must be configured separately, before or after
1951 <code>ovs-vswitchd</code> is started.
1956 If not specified, the default is implementation-specific.
1961 <group title="Client Failure Detection and Handling">
1962 <column name="max_backoff">
1963 Maximum number of milliseconds to wait between connection attempts.
1964 Default is implementation-specific.
1967 <column name="inactivity_probe">
1968 Maximum number of milliseconds of idle time on connection to the client
1969 before sending an inactivity probe message. If Open vSwitch does not
1970 communicate with the client for the specified number of seconds, it
1971 will send a probe. If a response is not received for the same
1972 additional amount of time, Open vSwitch assumes the connection has been
1973 broken and attempts to reconnect. Default is implementation-specific.
1977 <group title="Other Features">
1978 <column name="external_ids">
1979 Key-value pairs for use by external frameworks that integrate with Open
1980 vSwitch, rather than by Open vSwitch itself. System integrators should
1981 either use the Open vSwitch development mailing list to coordinate on
1982 common key-value definitions, or choose key names that are likely to be
1983 unique. No common key-value pairs are currently defined.
1988 <table name="NetFlow">
1989 A NetFlow target. NetFlow is a protocol that exports a number of
1990 details about terminating IP flows, such as the principals involved
1993 <column name="targets">
1994 NetFlow targets in the form
1995 <code><var>ip</var>:<var>port</var></code>. The <var>ip</var>
1996 must be specified numerically, not as a DNS name.
1999 <column name="engine_id">
2000 Engine ID to use in NetFlow messages. Defaults to datapath index
2004 <column name="engine_type">
2005 Engine type to use in NetFlow messages. Defaults to datapath
2006 index if not specified.
2009 <column name="active_timeout">
2010 The interval at which NetFlow records are sent for flows that are
2011 still active, in seconds. A value of <code>0</code> requests the
2012 default timeout (currently 600 seconds); a value of <code>-1</code>
2013 disables active timeouts.
2016 <column name="add_id_to_interface">
2017 <p>If this column's value is <code>false</code>, the ingress and egress
2018 interface fields of NetFlow flow records are derived from OpenFlow port
2019 numbers. When it is <code>true</code>, the 7 most significant bits of
2020 these fields will be replaced by the least significant 7 bits of the
2021 engine id. This is useful because many NetFlow collectors do not
2022 expect multiple switches to be sending messages from the same host, so
2023 they do not store the engine information which could be used to
2024 disambiguate the traffic.</p>
2025 <p>When this option is enabled, a maximum of 508 ports are supported.</p>
2028 <column name="external_ids">
2029 Key-value pairs for use by external frameworks that integrate with Open
2030 vSwitch, rather than by Open vSwitch itself. System integrators should
2031 either use the Open vSwitch development mailing list to coordinate on
2032 common key-value definitions, or choose key names that are likely to be
2033 unique. No common key-value pairs are currently defined.
2038 SSL configuration for an Open_vSwitch.
2040 <column name="private_key">
2041 Name of a PEM file containing the private key used as the switch's
2042 identity for SSL connections to the controller.
2045 <column name="certificate">
2046 Name of a PEM file containing a certificate, signed by the
2047 certificate authority (CA) used by the controller and manager,
2048 that certifies the switch's private key, identifying a trustworthy
2052 <column name="ca_cert">
2053 Name of a PEM file containing the CA certificate used to verify
2054 that the switch is connected to a trustworthy controller.
2057 <column name="bootstrap_ca_cert">
2058 If set to <code>true</code>, then Open vSwitch will attempt to
2059 obtain the CA certificate from the controller on its first SSL
2060 connection and save it to the named PEM file. If it is successful,
2061 it will immediately drop the connection and reconnect, and from then
2062 on all SSL connections must be authenticated by a certificate signed
2063 by the CA certificate thus obtained. <em>This option exposes the
2064 SSL connection to a man-in-the-middle attack obtaining the initial
2065 CA certificate.</em> It may still be useful for bootstrapping.
2068 <column name="external_ids">
2069 Key-value pairs for use by external frameworks that integrate with Open
2070 vSwitch, rather than by Open vSwitch itself. System integrators should
2071 either use the Open vSwitch development mailing list to coordinate on
2072 common key-value definitions, or choose key names that are likely to be
2073 unique. No common key-value pairs are currently defined.
2077 <table name="sFlow">
2078 <p>An sFlow(R) target. sFlow is a protocol for remote monitoring
2081 <column name="agent">
2082 Name of the network device whose IP address should be reported as the
2083 ``agent address'' to collectors. If not specified, the IP address
2084 defaults to the <ref table="Controller" column="local_ip"/> in the
2085 collector's <ref table="Controller"/>. If an agent IP address cannot be
2086 determined either way, sFlow is disabled.
2089 <column name="header">
2090 Number of bytes of a sampled packet to send to the collector.
2091 If not specified, the default is 128 bytes.
2094 <column name="polling">
2095 Polling rate in seconds to send port statistics to the collector.
2096 If not specified, defaults to 30 seconds.
2099 <column name="sampling">
2100 Rate at which packets should be sampled and sent to the collector.
2101 If not specified, defaults to 400, which means one out of 400
2102 packets, on average, will be sent to the collector.
2105 <column name="targets">
2106 sFlow targets in the form
2107 <code><var>ip</var>:<var>port</var></code>.
2110 <column name="external_ids">
2111 Key-value pairs for use by external frameworks that integrate with Open
2112 vSwitch, rather than by Open vSwitch itself. System integrators should
2113 either use the Open vSwitch development mailing list to coordinate on
2114 common key-value definitions, or choose key names that are likely to be
2115 unique. No common key-value pairs are currently defined.
2119 <table name="Capability">
2120 <p>Records in this table describe functionality supported by the hardware
2121 and software platform on which this Open vSwitch is based. Clients
2122 should not modify this table.</p>
2124 <p>A record in this table is meaningful only if it is referenced by the
2125 <ref table="Open_vSwitch" column="capabilities"/> column in the
2126 <ref table="Open_vSwitch"/> table. The key used to reference it, called
2127 the record's ``category,'' determines the meanings of the
2128 <ref column="details"/> column. The following general forms of
2129 categories are currently defined:</p>
2132 <dt><code>qos-<var>type</var></code></dt>
2133 <dd><var>type</var> is supported as the value for
2134 <ref column="type" table="QoS"/> in the <ref table="QoS"/> table.
2138 <column name="details">
2139 <p>Key-value pairs that describe capabilities. The meaning of the pairs
2140 depends on the category key that the <ref table="Open_vSwitch"
2141 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
2142 uses to reference this record, as described above.</p>
2144 <p>The presence of a record for category <code>qos-<var>type</var></code>
2145 indicates that the switch supports <var>type</var> as the value of
2146 the <ref table="QoS" column="type"/> column in the <ref table="QoS"/>
2147 table. The following key-value pairs are defined to further describe
2148 QoS capabilities:</p>
2151 <dt><code>n-queues</code></dt>
2152 <dd>Number of supported queues, as a positive integer. Keys in the
2153 <ref table="QoS" column="queues"/> column for <ref table="QoS"/>
2154 records whose <ref table="QoS" column="type"/> value
2155 equals <var>type</var> must range between 0 and this value minus one,