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-type</code></dt>
32 <dd>An identifier for the switch type, such as
33 <code>XenServer</code> or <code>KVM</code>.</dd>
34 <dt><code>system-version</code></dt>
35 <dd>The version of the switch software, such as
36 <code>5.6.0</code> on XenServer.</dd>
37 <dt><code>system-id</code></dt>
38 <dd>A unique identifier for the Open vSwitch's physical host.
39 The form of the identifier depends on the type of the host.
40 On a Citrix XenServer, this will likely be the same as
41 <code>xs-system-uuid</code>.</dd>
42 <dt><code>xs-system-uuid</code></dt>
43 <dd>The Citrix XenServer universally unique identifier for the
44 physical host as displayed by <code>xe host-list</code>.</dd>
49 <group title="Status">
50 <column name="next_cfg">
51 Sequence number for client to increment. When a client modifies
52 any part of the database configuration and wishes to wait for
53 Open vSwitch to finish applying the changes, it may increment
57 <column name="cur_cfg">
58 Sequence number that Open vSwitch sets to the current value of
59 <ref column="next_cfg"/> after it finishes applying a set of
60 configuration changes.
63 <column name="capabilities">
64 Describes functionality supported by the hardware and software platform
65 on which this Open vSwitch is based. Clients should not modify this
66 column. See the <ref table="Capability"/> description for defined
67 capability categories and the meaning of associated
68 <ref table="Capability"/> records.
71 <column name="statistics">
73 Key-value pairs that report statistics about a system running an Open
74 vSwitch. These are updated periodically (currently, every 5
75 seconds). Key-value pairs that cannot be determined or that do not
76 apply to a platform are omitted.
80 <dt><code>cpu</code></dt>
83 Number of CPU processors, threads, or cores currently online and
84 available to the operating system on which Open vSwitch is
85 running, as an integer. This may be less than the number
86 installed, if some are not online or if they are not available to
90 Open vSwitch userspace processes are not multithreaded, but the
91 Linux kernel-based datapath is.
95 <dt><code>load_average</code></dt>
98 A comma-separated list of three floating-point numbers,
99 representing the system load average over the last 1, 5, and 15
100 minutes, respectively.
104 <dt><code>memory</code></dt>
107 A comma-separated list of integers, each of which represents a
108 quantity of memory in kilobytes that describes the operating
109 system on which Open vSwitch is running. In respective order,
114 <li>Total amount of RAM allocated to the OS.</li>
115 <li>RAM allocated to the OS that is in use.</li>
116 <li>RAM that can be flushed out to disk or otherwise discarded
117 if that space is needed for another purpose. This number is
118 necessarily less than or equal to the previous value.</li>
119 <li>Total disk space allocated for swap.</li>
120 <li>Swap space currently in use.</li>
124 On Linux, all five values can be determined and are included. On
125 other operating systems, only the first two values can be
126 determined, so the list will only have two values.
130 <dt><code>process_</code><var>name</var></dt>
133 One such key-value pair will exist for each running Open vSwitch
134 daemon process, with <var>name</var> replaced by the daemon's
135 name (e.g. <code>process_ovs-vswitchd</code>). The value is a
136 comma-separated list of integers. The integers represent the
137 following, with memory measured in kilobytes and durations in
142 <li>The process's virtual memory size.</li>
143 <li>The process's resident set size.</li>
144 <li>The amount of user and system CPU time consumed by the
146 <li>The number of times that the process has crashed and been
147 automatically restarted by the monitor.</li>
148 <li>The duration since the process was started.</li>
149 <li>The duration for which the process has been running.</li>
153 The interpretation of some of these values depends on whether the
154 process was started with the <option>--monitor</option>. If it
155 was not, then the crash count will always be 0 and the two
156 durations will always be the same. If <option>--monitor</option>
157 was given, then the crash count may be positive; if it is, the
158 latter duration is the amount of time since the most recent crash
163 There will be one key-value pair for each file in Open vSwitch's
164 ``run directory'' (usually <code>/var/run/openvswitch</code>)
165 whose name ends in <code>.pid</code>, whose contents are a
166 process ID, and which is locked by a running process. The
167 <var>name</var> is taken from the pidfile's name.
171 Currently Open vSwitch is only able to obtain all of the above
172 detail on Linux systems. On other systems, the same key-value
173 pairs will be present but the values will always be the empty
178 <dt><code>file_systems</code></dt>
181 A space-separated list of information on local, writable file
182 systems. Each item in the list describes one file system and
183 consists in turn of a comma-separated list of the following:
187 <li>Mount point, e.g. <code>/</code> or <code>/var/log</code>.
188 Any spaces or commas in the mount point are replaced by
190 <li>Total size, in kilobytes, as an integer.</li>
191 <li>Amount of storage in use, in kilobytes, as an integer.</li>
195 This key-value pair is omitted if there are no local, writable
196 file systems or if Open vSwitch cannot obtain the needed
204 <group title="Database Configuration">
206 These columns primarily configure the Open vSwitch database
207 (<code>ovsdb-server</code>), not the Open vSwitch switch
208 (<code>ovs-vswitchd</code>). The OVSDB database also uses the <ref
209 column="ssl"/> settings.
213 The Open vSwitch switch does read the database configuration to
214 determine remote IP addresses to which in-band control should apply.
217 <column name="manager_options">
218 Database clients to which the Open vSwitch database server should
219 connect or to which it should listen, along with options for how these
220 connection should be configured. See the <ref table="Manager"/> table
221 for more information.
224 <column name="managers">
226 Remote database clients to which the Open vSwitch's database server
227 should connect or to which it should listen. Adding an OVSDB target
228 to this set is equivalent to adding it to <ref
229 column="manager_options"/> with all of the default options.
233 Use of this column is deprecated and may be removed sometime in the
234 future. New applications should use and set <ref
235 column="manager_options"/> instead.
241 <table name="Bridge">
243 Configuration for a bridge within an
244 <ref table="Open_vSwitch"/>.
247 A <ref table="Bridge"/> record represents an Ethernet switch with one or
248 more ``ports,'' which are the <ref table="Port"/> records pointed to by
249 the <ref table="Bridge"/>'s <ref column="ports"/> column.
252 <group title="Core Features">
254 Bridge identifier. Should be alphanumeric and no more than about 8
255 bytes long. Must be unique among the names of ports, interfaces, and
259 <column name="ports">
260 Ports included in the bridge.
263 <column name="mirrors">
264 Port mirroring configuration.
267 <column name="netflow">
268 NetFlow configuration.
271 <column name="sflow">
275 <column name="flood_vlans">
276 VLAN IDs of VLANs on which MAC address learning should be disabled, so
277 that packets are flooded instead of being sent to specific ports that
278 are believed to contain packets' destination MACs. This should
279 ordinarily be used to disable MAC learning on VLANs used for mirroring
280 (RSPAN VLANs). It may also be useful for debugging.
284 <group title="OpenFlow Configuration">
285 <column name="controller">
286 OpenFlow controller set. If unset, then no OpenFlow controllers
290 <column name="fail_mode">
291 <p>When a controller is configured, it is, ordinarily, responsible
292 for setting up all flows on the switch. Thus, if the connection to
293 the controller fails, no new network connections can be set up.
294 If the connection to the controller stays down long enough,
295 no packets can pass through the switch at all. This setting
296 determines the switch's response to such a situation. It may be set
297 to one of the following:
299 <dt><code>standalone</code></dt>
300 <dd>If no message is received from the controller for three
301 times the inactivity probe interval
302 (see <ref column="inactivity_probe"/>), then Open vSwitch
303 will take over responsibility for setting up flows. In
304 this mode, Open vSwitch causes the bridge to act like an
305 ordinary MAC-learning switch. Open vSwitch will continue
306 to retry connecting to the controller in the background
307 and, when the connection succeeds, it will discontinue its
308 standalone behavior.</dd>
309 <dt><code>secure</code></dt>
310 <dd>Open vSwitch will not set up flows on its own when the
311 controller connection fails or when no controllers are
312 defined. The bridge will continue to retry connecting to
313 any defined controllers forever.</dd>
316 <p>If this value is unset, the default is implementation-specific.</p>
317 <p>When more than one controller is configured,
318 <ref column="fail_mode"/> is considered only when none of the
319 configured controllers can be contacted.</p>
322 <column name="datapath_id">
323 Reports the OpenFlow datapath ID in use. Exactly 16 hex
324 digits. (Setting this column will have no useful effect. Set
325 <ref column="other_config"/>:<code>other-config</code>
330 <group title="Other Features">
331 <column name="datapath_type">
332 Name of datapath provider. The kernel datapath has
333 type <code>system</code>. The userspace datapath has
334 type <code>netdev</code>.
337 <column name="external_ids">
338 Key-value pairs for use by external frameworks that integrate
339 with Open vSwitch, rather than by Open vSwitch itself. System
340 integrators should either use the Open vSwitch development
341 mailing list to coordinate on common key-value definitions, or
342 choose key names that are likely to be unique. The currently
343 defined key-value pairs are:
345 <dt><code>bridge-id</code></dt>
346 <dd>A unique identifier of the bridge. On Citrix XenServer this
347 will commonly be the same as <code>xs-network-uuids</code>.</dd>
348 <dt><code>xs-network-uuids</code></dt>
349 <dd>Semicolon-delimited set of universally unique identifier(s) for
350 the network with which this bridge is associated on a Citrix
351 XenServer host. The network identifiers are RFC 4122 UUIDs as
352 displayed by, e.g., <code>xe network-list</code>.</dd>
356 <column name="other_config">
357 Key-value pairs for configuring rarely used bridge
358 features. The currently defined key-value pairs are:
360 <dt><code>datapath-id</code></dt>
362 digits to set the OpenFlow datapath ID to a specific
363 value. May not be all-zero.</dd>
364 <dt><code>disable-in-band</code></dt>
365 <dd>If set to <code>true</code>, disable in-band control on
366 the bridge regardless of controller and manager settings.</dd>
367 <dt><code>hwaddr</code></dt>
368 <dd>An Ethernet address in the form
369 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>
370 to set the hardware address of the local port and influence the
377 <table name="Port" table="Port or bond configuration.">
378 <p>A port within a <ref table="Bridge"/>.</p>
379 <p>Most commonly, a port has exactly one ``interface,'' pointed to by its
380 <ref column="interfaces"/> column. Such a port logically
381 corresponds to a port on a physical Ethernet switch. A port
382 with more than one interface is a ``bonded port'' (see
383 <ref group="Bonding Configuration"/>).</p>
384 <p>Some properties that one might think as belonging to a port are actually
385 part of the port's <ref table="Interface"/> members.</p>
388 Port name. Should be alphanumeric and no more than about 8
389 bytes long. May be the same as the interface name, for
390 non-bonded ports. Must otherwise be unique among the names of
391 ports, interfaces, and bridges on a host.
394 <column name="interfaces">
395 The port's interfaces. If there is more than one, this is a
399 <group title="VLAN Configuration">
400 <p>A bridge port must be configured for VLANs in one of two
401 mutually exclusive ways:
403 <li>A ``trunk port'' has an empty value for <ref
404 column="tag"/>. Its <ref column="trunks"/> value may be
405 empty or non-empty.</li>
406 <li>An ``implicitly tagged VLAN port'' or ``access port''
407 has an nonempty value for <ref column="tag"/>. Its
408 <ref column="trunks"/> value must be empty.</li>
410 If <ref column="trunks"/> and <ref column="tag"/> are both
411 nonempty, the configuration is ill-formed.
416 If this is an access port (see above), the port's implicitly
417 tagged VLAN. Must be empty if this is a trunk port.
420 Frames arriving on trunk ports will be forwarded to this
421 port only if they are tagged with the given VLAN (or, if
422 <ref column="tag"/> is 0, then if they lack a VLAN header).
423 Frames arriving on other access ports will be forwarded to
424 this port only if they have the same <ref column="tag"/>
425 value. Frames forwarded to this port will not have an
429 When a frame with a 802.1Q header that indicates a nonzero
430 VLAN is received on an access port, it is discarded.
434 <column name="trunks">
436 If this is a trunk port (see above), the 802.1Q VLAN(s) that
437 this port trunks; if it is empty, then the port trunks all
438 VLANs. Must be empty if this is an access port.
441 Frames arriving on trunk ports are dropped if they are not
442 in one of the specified VLANs. For this purpose, packets
443 that have no VLAN header are treated as part of VLAN 0.
448 <group title="Bonding Configuration">
449 <p>A port that has more than one interface is a ``bonded port.''
450 Bonding allows for load balancing and fail-over. Open vSwitch
451 supports ``source load balancing'' (SLB) bonding, which
452 assigns flows to slaves based on source MAC address, with
453 periodic rebalancing as traffic patterns change. This form of
454 bonding does not require 802.3ad or other special support from
455 the upstream switch to which the slave devices are
458 <p>These columns apply only to bonded ports. Their values are
459 otherwise ignored.</p>
461 <column name="bond_updelay">
462 <p>For a bonded port, the number of milliseconds for which carrier must
463 stay up on an interface before the interface is considered to be up.
464 Specify <code>0</code> to enable the interface immediately.</p>
465 <p>This setting is honored only when at least one bonded interface is
466 already enabled. When no interfaces are enabled, then the first bond
467 interface to come up is enabled immediately.</p>
470 <column name="bond_downdelay">
471 For a bonded port, the number of milliseconds for which carrier must
472 stay down on an interface before the interface is considered to be
473 down. Specify <code>0</code> to disable the interface immediately.
476 <column name="bond_fake_iface">
477 For a bonded port, whether to create a fake internal interface with the
478 name of the port. Use only for compatibility with legacy software that
483 <group title="Other Features">
485 Quality of Service configuration for this port.
489 The MAC address to use for this port for the purpose of choosing the
490 bridge's MAC address. This column does not necessarily reflect the
491 port's actual MAC address, nor will setting it change the port's actual
495 <column name="fake_bridge">
496 Does this port represent a sub-bridge for its tagged VLAN within the
497 Bridge? See ovs-vsctl(8) for more information.
500 <column name="external_ids">
502 Key-value pairs for use by external frameworks that integrate with
503 Open vSwitch, rather than by Open vSwitch itself. System integrators
504 should either use the Open vSwitch development mailing list to
505 coordinate on common key-value definitions, or choose key names that
506 are likely to be unique.
509 No key-value pairs native to <ref table="Port"/> are currently
510 defined. For fake bridges (see the <ref column="fake_bridge"/>
511 column), external IDs for the fake bridge are defined here by
512 prefixing a <ref table="Bridge"/> <ref table="Bridge"
513 column="external_ids"/> key with <code>fake-bridge-</code>,
514 e.g. <code>fake-bridge-xs-network-uuids</code>.
518 <column name="other_config">
519 Key-value pairs for configuring rarely used port features. The
520 currently defined key-value pairs are:
522 <dt><code>hwaddr</code></dt>
523 <dd>An Ethernet address in the form
524 <code><var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var></code>.</dd>
525 <dt><code>bond-rebalance-interval</code></dt>
526 <dd>For a bonded port, the number of milliseconds between
527 successive attempts to rebalance the bond, that is, to
528 move source MACs and their flows from one interface on
529 the bond to another in an attempt to keep usage of each
530 interface roughly equal. The default is 10000 (10
531 seconds), and the minimum is 1000 (1 second).</dd>
537 <table name="Interface" title="One physical network device in a Port.">
538 An interface within a <ref table="Port"/>.
540 <group title="Core Features">
542 Interface name. Should be alphanumeric and no more than about 8 bytes
543 long. May be the same as the port name, for non-bonded ports. Must
544 otherwise be unique among the names of ports, interfaces, and bridges
549 <p>Ethernet address to set for this interface. If unset then the
550 default MAC address is used:</p>
552 <li>For the local interface, the default is the lowest-numbered MAC
553 address among the other bridge ports, either the value of the
554 <ref table="Port" column="mac"/> in its <ref table="Port"/> record,
555 if set, or its actual MAC (for bonded ports, the MAC of its slave
556 whose name is first in alphabetical order). Internal ports and
557 bridge ports that are used as port mirroring destinations (see the
558 <ref table="Mirror"/> table) are ignored.</li>
559 <li>For other internal interfaces, the default MAC is randomly
561 <li>External interfaces typically have a MAC address associated with
564 <p>Some interfaces may not have a software-controllable MAC
568 <column name="ofport">
569 <p>OpenFlow port number for this interface. Unlike most columns, this
570 column's value should be set only by Open vSwitch itself. Other
571 clients should set this column to an empty set (the default) when
572 creating an <ref table="Interface"/>.</p>
573 <p>Open vSwitch populates this column when the port number becomes
574 known. If the interface is successfully added,
575 <ref column="ofport"/> will be set to a number between 1 and 65535
576 (generally either in the range 1 to 65279, inclusive, or 65534, the
577 port number for the OpenFlow ``local port''). If the interface
578 cannot be added then Open vSwitch sets this column
583 <group title="System-Specific Details">
585 The interface type, one of:
587 <dt><code>system</code></dt>
588 <dd>An ordinary network device, e.g. <code>eth0</code> on Linux.
589 Sometimes referred to as ``external interfaces'' since they are
590 generally connected to hardware external to that on which the Open
591 vSwitch is running. The empty string is a synonym for
592 <code>system</code>.</dd>
593 <dt><code>internal</code></dt>
594 <dd>A simulated network device that sends and receives traffic. An
595 internal interface whose <ref column="name"/> is the same as its
596 bridge's <ref table="Open_vSwitch" column="name"/> is called the
597 ``local interface.'' It does not make sense to bond an internal
598 interface, so the terms ``port'' and ``interface'' are often used
599 imprecisely for internal interfaces.</dd>
600 <dt><code>tap</code></dt>
601 <dd>A TUN/TAP device managed by Open vSwitch.</dd>
602 <dt><code>gre</code></dt>
603 <dd>An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
604 tunnel. Each tunnel must be uniquely identified by the
605 combination of <code>remote_ip</code>, <code>local_ip</code>, and
606 <code>in_key</code>. Note that if two ports are defined that are
607 the same except one has an optional identifier and the other does
608 not, the more specific one is matched first. <code>in_key</code>
609 is considered more specific than <code>local_ip</code> if a port
610 defines one and another port defines the other. The following
611 options may be specified in the <ref column="options"/> column:
613 <dt><code>remote_ip</code></dt>
614 <dd>Required. The tunnel endpoint.</dd>
617 <dt><code>local_ip</code></dt>
618 <dd>Optional. The destination IP that received packets must
619 match. Default is to match all addresses.</dd>
622 <dt><code>in_key</code></dt>
623 <dd>Optional. The GRE key that received packets must contain.
624 It may either be a 32-bit number (no key and a key of 0 are
625 treated as equivalent) or the word <code>flow</code>. If
626 <code>flow</code> is specified then any key will be accepted
627 and the key will be placed in the <code>tun_id</code> field
628 for matching in the flow table. The ovs-ofctl manual page
629 contains additional information about matching fields in
630 OpenFlow flows. Default is no key.</dd>
633 <dt><code>out_key</code></dt>
634 <dd>Optional. The GRE key to be set on outgoing packets. It may
635 either be a 32-bit number or the word <code>flow</code>. If
636 <code>flow</code> is specified then the key may be set using
637 the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0
638 is used in the absence of an action). The ovs-ofctl manual
639 page contains additional information about the Nicira OpenFlow
640 vendor extensions. Default is no key.</dd>
643 <dt><code>key</code></dt>
644 <dd>Optional. Shorthand to set <code>in_key</code> and
645 <code>out_key</code> at the same time.</dd>
648 <dt><code>tos</code></dt>
649 <dd>Optional. The value of the ToS bits to be set on the
650 encapsulating packet. It may also be the word
651 <code>inherit</code>, in which case the ToS will be copied from
652 the inner packet if it is IPv4 or IPv6 (otherwise it will be
653 0). Note that the ECN fields are always inherited. Default is
657 <dt><code>ttl</code></dt>
658 <dd>Optional. The TTL to be set on the encapsulating packet.
659 It may also be the word <code>inherit</code>, in which case the
660 TTL will be copied from the inner packet if it is IPv4 or IPv6
661 (otherwise it will be the system default, typically 64).
662 Default is the system default TTL.</dd>
665 <dt><code>csum</code></dt>
666 <dd>Optional. Compute GRE checksums on outgoing packets.
667 Checksums present on incoming packets will be validated
668 regardless of this setting. Note that GRE checksums
669 impose a significant performance penalty as they cover the
670 entire packet. As the contents of the packet is typically
671 covered by L3 and L4 checksums, this additional checksum only
672 adds value for the GRE and encapsulated Ethernet headers.
673 Default is disabled, set to <code>true</code> to enable.</dd>
676 <dt><code>pmtud</code></dt>
677 <dd>Optional. Enable tunnel path MTU discovery. If enabled
678 ``ICMP destination unreachable - fragmentation'' needed
679 messages will be generated for IPv4 packets with the DF bit set
680 and IPv6 packets above the minimum MTU if the packet size
681 exceeds the path MTU minus the size of the tunnel headers. It
682 also forces the encapsulating packet DF bit to be set (it is
683 always set if the inner packet implies path MTU discovery).
684 Note that this option causes behavior that is typically
685 reserved for routers and therefore is not entirely in
686 compliance with the IEEE 802.1D specification for bridges.
687 Default is enabled, set to <code>false</code> to disable.</dd>
690 <dt><code>header_cache</code></dt>
691 <dd>Optional. Enable caching of tunnel headers and the output
692 path. This can lead to a significant performance increase
693 without changing behavior. In general it should not be
694 necessary to adjust this setting. However, the caching can
695 bypass certain components of the IP stack (such as IP tables)
696 and it may be useful to disable it if these features are
697 required or as a debugging measure. Default is enabled, set to
698 <code>false</code> to disable. If IPsec is enabled through the
699 <ref column="other_config"/> parameters, header caching will be
700 automatically disabled.</dd>
703 <dt><code>capwap</code></dt>
704 <dd>Ethernet tunneling over the UDP transport portion of CAPWAP
705 (RFC 5415). This allows interoperability with certain switches
706 where GRE is not available. Note that only the tunneling component
707 of the protocol is implemented. Due to the non-standard use of
708 CAPWAP, UDP ports 58881 and 58882 are used as the source and
709 destinations ports respectivedly. Each tunnel must be uniquely
710 identified by the combination of <code>remote_ip</code> and
711 <code>local_ip</code>. If two ports are defined that are the same
712 except one includes <code>local_ip</code> and the other does not,
713 the more specific one is matched first. CAPWAP support is not
714 available on all platforms. Currently it is only supported in the
715 Linux kernel module with kernel versions >= 2.6.25. The following
716 options may be specified in the <ref column="options"/> column:
718 <dt><code>remote_ip</code></dt>
719 <dd>Required. The tunnel endpoint.</dd>
722 <dt><code>local_ip</code></dt>
723 <dd>Optional. The destination IP that received packets must
724 match. Default is to match all addresses.</dd>
727 <dt><code>tos</code></dt>
728 <dd>Optional. The value of the ToS bits to be set on the
729 encapsulating packet. It may also be the word
730 <code>inherit</code>, in which case the ToS will be copied from
731 the inner packet if it is IPv4 or IPv6 (otherwise it will be
732 0). Note that the ECN fields are always inherited. Default is
736 <dt><code>ttl</code></dt>
737 <dd>Optional. The TTL to be set on the encapsulating packet.
738 It may also be the word <code>inherit</code>, in which case the
739 TTL will be copied from the inner packet if it is IPv4 or IPv6
740 (otherwise it will be the system default, typically 64).
741 Default is the system default TTL.</dd>
744 <dt><code>pmtud</code></dt>
745 <dd>Optional. Enable tunnel path MTU discovery. If enabled
746 ``ICMP destination unreachable - fragmentation'' needed
747 messages will be generated for IPv4 packets with the DF bit set
748 and IPv6 packets above the minimum MTU if the packet size
749 exceeds the path MTU minus the size of the tunnel headers. It
750 also forces the encapsulating packet DF bit to be set (it is
751 always set if the inner packet implies path MTU discovery).
752 Note that this option causes behavior that is typically
753 reserved for routers and therefore is not entirely in
754 compliance with the IEEE 802.1D specification for bridges.
755 Default is enabled, set to <code>false</code> to disable.</dd>
758 <dt><code>header_cache</code></dt>
759 <dd>Optional. Enable caching of tunnel headers and the output
760 path. This can lead to a significant performance increase
761 without changing behavior. In general it should not be
762 necessary to adjust this setting. However, the caching can
763 bypass certain components of the IP stack (such as IP tables)
764 and it may be useful to disable it if these features are
765 required or as a debugging measure. Default is enabled, set to
766 <code>false</code> to disable.</dd>
769 <dt><code>patch</code></dt>
772 A pair of virtual devices that act as a patch cable. The <ref
773 column="options"/> column must have the following key-value pair:
776 <dt><code>peer</code></dt>
778 The <ref column="name"/> of the <ref table="Interface"/> for
779 the other side of the patch. The named <ref
780 table="Interface"/>'s own <code>peer</code> option must specify
781 this <ref table="Interface"/>'s name. That is, the two patch
782 interfaces must have reversed <ref column="name"/> and
783 <code>peer</code> values.
790 <column name="options">
791 Configuration options whose interpretation varies based on
792 <ref column="type"/>.
795 <column name="status">
797 Key-value pairs that report port status. Supported status
798 values are <code>type</code>-dependent.
800 <p>The only currently defined key-value pair is:</p>
802 <dt><code>source_ip</code></dt>
803 <dd>The source IP address used for an IPv4 tunnel end-point,
804 such as <code>gre</code> or <code>capwap</code>. Not
805 supported by all implementations.</dd>
810 <group title="Ingress Policing">
812 These settings control ingress policing for packets received on this
813 interface. On a physical interface, this limits the rate at which
814 traffic is allowed into the system from the outside; on a virtual
815 interface (one connected to a virtual machine), this limits the rate at
816 which the VM is able to transmit.
819 Policing is a simple form of quality-of-service that simply drops
820 packets received in excess of the configured rate. Due to its
821 simplicity, policing is usually less accurate and less effective than
822 egress QoS (which is configured using the <ref table="QoS"/> and <ref
823 table="Queue"/> tables).
826 Policing is currently implemented only on Linux. The Linux
827 implementation uses a simple ``token bucket'' approach:
831 The size of the bucket corresponds to <ref
832 column="ingress_policing_burst"/>. Initially the bucket is full.
835 Whenever a packet is received, its size (converted to tokens) is
836 compared to the number of tokens currently in the bucket. If the
837 required number of tokens are available, they are removed and the
838 packet is forwarded. Otherwise, the packet is dropped.
841 Whenever it is not full, the bucket is refilled with tokens at the
842 rate specified by <ref column="ingress_policing_rate"/>.
846 Policing interacts badly with some network protocols, and especially
847 with fragmented IP packets. Suppose that there is enough network
848 activity to keep the bucket nearly empty all the time. Then this token
849 bucket algorithm will forward a single packet every so often, with the
850 period depending on packet size and on the configured rate. All of the
851 fragments of an IP packets are normally transmitted back-to-back, as a
852 group. In such a situation, therefore, only one of these fragments
853 will be forwarded and the rest will be dropped. IP does not provide
854 any way for the intended recipient to ask for only the remaining
855 fragments. In such a case there are two likely possibilities for what
856 will happen next: either all of the fragments will eventually be
857 retransmitted (as TCP will do), in which case the same problem will
858 recur, or the sender will not realize that its packet has been dropped
859 and data will simply be lost (as some UDP-based protocols will do).
860 Either way, it is possible that no forward progress will ever occur.
862 <column name="ingress_policing_rate">
864 Maximum rate for data received on this interface, in kbps. Data
865 received faster than this rate is dropped. Set to <code>0</code>
866 (the default) to disable policing.
870 <column name="ingress_policing_burst">
871 <p>Maximum burst size for data received on this interface, in kb. The
872 default burst size if set to <code>0</code> is 1000 kb. This value
873 has no effect if <ref column="ingress_policing_rate"/>
874 is <code>0</code>.</p>
876 Specifying a larger burst size lets the algorithm be more forgiving,
877 which is important for protocols like TCP that react severely to
878 dropped packets. The burst size should be at least the size of the
879 interface's MTU. Specifying a value that is numerically at least as
880 large as 10% of <ref column="ingress_policing_rate"/> helps TCP come
881 closer to achieving the full rate.
886 <group title="Other Features">
887 <column name="external_ids">
888 Key-value pairs for use by external frameworks that integrate
889 with Open vSwitch, rather than by Open vSwitch itself. System
890 integrators should either use the Open vSwitch development
891 mailing list to coordinate on common key-value definitions, or
892 choose key names that are likely to be unique. The currently
893 defined common key-value pairs are:
895 <dt><code>attached-mac</code></dt>
897 The MAC address programmed into the ``virtual hardware'' for this
898 interface, in the form
899 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>.
900 For Citrix XenServer, this is the value of the <code>MAC</code>
901 field in the VIF record for this interface.</dd>
902 <dt><code>iface-id</code></dt>
903 <dd>A system-unique identifier for the interface. On XenServer,
904 this will commonly be the same as <code>xs-vif-uuid</code>.</dd>
907 Additionally the following key-value pairs specifically
908 apply to an interface that represents a virtual Ethernet interface
909 connected to a virtual machine. These key-value pairs should not be
910 present for other types of interfaces. Keys whose names end
911 in <code>-uuid</code> have values that uniquely identify the entity
912 in question. For a Citrix XenServer hypervisor, these values are
913 UUIDs in RFC 4122 format. Other hypervisors may use other
916 <p>The currently defined key-value pairs for XenServer are:</p>
918 <dt><code>xs-vif-uuid</code></dt>
919 <dd>The virtual interface associated with this interface.</dd>
920 <dt><code>xs-network-uuid</code></dt>
921 <dd>The virtual network to which this interface is attached.</dd>
922 <dt><code>xs-vm-uuid</code></dt>
923 <dd>The VM to which this interface belongs.</dd>
927 <column name="other_config">
928 Key-value pairs for rarely used interface features. Currently,
929 the only keys are for configuring GRE-over-IPsec, which is only
930 available through the <code>openvswitch-ipsec</code> package for
931 Debian. The currently defined key-value pairs are:
933 <dt><code>ipsec_local_ip</code></dt>
934 <dd>Required key for GRE-over-IPsec interfaces. Additionally,
935 the <ref column="type"/> must be <code>gre</code> and the
936 <code>ipsec_psk</code> <ref column="other_config"/> key must
937 be set. The <code>in_key</code>, <code>out_key</code>, and
938 <code>key</code> <ref column="options"/> must not be
940 <dt><code>ipsec_psk</code></dt>
941 <dd>Required key for GRE-over-IPsec interfaces. Specifies a
942 pre-shared key for authentication that must be identical on
943 both sides of the tunnel. Additionally, the
944 <code>ipsec_local_ip</code> key must also be set.</dd>
948 <column name="statistics">
950 Key-value pairs that report interface statistics. The current
951 implementation updates these counters periodically. In the future,
952 we plan to, instead, update them when an interface is created, when
953 they are queried (e.g. using an OVSDB <code>select</code> operation),
954 and just before an interface is deleted due to virtual interface
955 hot-unplug or VM shutdown, and perhaps at other times, but not on any
956 regular periodic basis.</p>
958 The currently defined key-value pairs are listed below. These are
959 the same statistics reported by OpenFlow in its <code>struct
960 ofp_port_stats</code> structure. If an interface does not support a
961 given statistic, then that pair is omitted.</p>
964 Successful transmit and receive counters:
966 <dt><code>rx_packets</code></dt>
967 <dd>Number of received packets.</dd>
968 <dt><code>rx_bytes</code></dt>
969 <dd>Number of received bytes.</dd>
970 <dt><code>tx_packets</code></dt>
971 <dd>Number of transmitted packets.</dd>
972 <dt><code>tx_bytes</code></dt>
973 <dd>Number of transmitted bytes.</dd>
979 <dt><code>rx_dropped</code></dt>
980 <dd>Number of packets dropped by RX.</dd>
981 <dt><code>rx_frame_err</code></dt>
982 <dd>Number of frame alignment errors.</dd>
983 <dt><code>rx_over_err</code></dt>
984 <dd>Number of packets with RX overrun.</dd>
985 <dt><code>rx_crc_err</code></dt>
986 <dd>Number of CRC errors.</dd>
987 <dt><code>rx_errors</code></dt>
989 Total number of receive errors, greater than or equal
990 to the sum of the above.
997 <dt><code>tx_dropped</code></dt>
998 <dd>Number of packets dropped by TX.</dd>
999 <dt><code>collisions</code></dt>
1000 <dd>Number of collisions.</dd>
1001 <dt><code>tx_errors</code></dt>
1003 Total number of transmit errors, greater
1004 than or equal to the sum of the above.
1013 <table name="QoS" title="Quality of Service configuration">
1014 <p>Quality of Service (QoS) configuration for each Port that
1017 <column name="type">
1018 <p>The type of QoS to implement. The <ref table="Open_vSwitch"
1019 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
1020 identifies the types that a switch actually supports. The currently
1021 defined types are listed below:</p>
1023 <dt><code>linux-htb</code></dt>
1025 Linux ``hierarchy token bucket'' classifier. See tc-htb(8) (also at
1026 <code>http://linux.die.net/man/8/tc-htb</code>) and the HTB manual
1027 (<code>http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm</code>)
1028 for information on how this classifier works and how to configure it.
1032 <dt><code>linux-hfsc</code></dt>
1034 Linux "Hierarchical Fair Service Curve" classifier.
1035 See <code>http://linux-ip.net/articles/hfsc.en/</code> for
1036 information on how this classifier works.
1041 <column name="queues">
1042 <p>A map from queue numbers to <ref table="Queue"/> records. The
1043 supported range of queue numbers depend on <ref column="type"/>. The
1044 queue numbers are the same as the <code>queue_id</code> used in
1045 OpenFlow in <code>struct ofp_action_enqueue</code> and other
1046 structures. Queue 0 is used by OpenFlow output actions that do not
1047 specify a specific queue.</p>
1050 <column name="other_config">
1051 <p>Key-value pairs for configuring QoS features that depend on
1052 <ref column="type"/>.</p>
1053 <p>The <code>linux-htb</code> and <code>linux-hfsc</code> classes support
1054 the following key-value pairs:</p>
1056 <dt><code>max-rate</code></dt>
1057 <dd>Maximum rate shared by all queued traffic, in bit/s.
1058 Optional. If not specified, for physical interfaces, the
1059 default is the link rate. For other interfaces or if the
1060 link rate cannot be determined, the default is currently 100
1065 <column name="external_ids">
1066 Key-value pairs for use by external frameworks that integrate with Open
1067 vSwitch, rather than by Open vSwitch itself. System integrators should
1068 either use the Open vSwitch development mailing list to coordinate on
1069 common key-value definitions, or choose key names that are likely to be
1070 unique. No common key-value pairs are currently defined.
1074 <table name="Queue" title="QoS output queue.">
1075 <p>A configuration for a port output queue, used in configuring Quality of
1076 Service (QoS) features. May be referenced by <ref column="queues"
1077 table="QoS"/> column in <ref table="QoS"/> table.</p>
1079 <column name="other_config">
1080 <p>Key-value pairs for configuring the output queue. The supported
1081 key-value pairs and their meanings depend on the <ref column="type"/>
1082 of the <ref column="QoS"/> records that reference this row.</p>
1083 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1084 column="type"/> of <code>min-rate</code> are:</p>
1086 <dt><code>min-rate</code></dt>
1087 <dd>Minimum guaranteed bandwidth, in bit/s. Required. The
1088 floor value is 1500 bytes/s (12,000 bit/s).</dd>
1090 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1091 column="type"/> of <code>linux-htb</code> are:</p>
1093 <dt><code>min-rate</code></dt>
1094 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1095 <dt><code>max-rate</code></dt>
1096 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1097 queue's rate will not be allowed to exceed the specified value, even
1098 if excess bandwidth is available. If unspecified, defaults to no
1100 <dt><code>burst</code></dt>
1101 <dd>Burst size, in bits. This is the maximum amount of ``credits''
1102 that a queue can accumulate while it is idle. Optional. Details of
1103 the <code>linux-htb</code> implementation require a minimum burst
1104 size, so a too-small <code>burst</code> will be silently
1106 <dt><code>priority</code></dt>
1107 <dd>A nonnegative 32-bit integer. Defaults to 0 if
1108 unspecified. A queue with a smaller <code>priority</code>
1109 will receive all the excess bandwidth that it can use before
1110 a queue with a larger value receives any. Specific priority
1111 values are unimportant; only relative ordering matters.</dd>
1113 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1114 column="type"/> of <code>linux-hfsc</code> are:</p>
1116 <dt><code>min-rate</code></dt>
1117 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1118 <dt><code>max-rate</code></dt>
1119 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1120 queue's rate will not be allowed to exceed the specified value, even
1121 if excess bandwidth is available. If unspecified, defaults to no
1126 <column name="external_ids">
1127 Key-value pairs for use by external frameworks that integrate with Open
1128 vSwitch, rather than by Open vSwitch itself. System integrators should
1129 either use the Open vSwitch development mailing list to coordinate on
1130 common key-value definitions, or choose key names that are likely to be
1131 unique. No common key-value pairs are currently defined.
1135 <table name="Mirror" title="Port mirroring (SPAN/RSPAN).">
1136 <p>A port mirror within a <ref table="Bridge"/>.</p>
1137 <p>A port mirror configures a bridge to send selected frames to special
1138 ``mirrored'' ports, in addition to their normal destinations. Mirroring
1139 traffic may also be referred to as SPAN or RSPAN, depending on the
1140 mechanism used for delivery.</p>
1142 <column name="name">
1143 Arbitrary identifier for the <ref table="Mirror"/>.
1146 <group title="Selecting Packets for Mirroring">
1147 <column name="select_all">
1148 If true, every packet arriving or departing on any port is
1149 selected for mirroring.
1152 <column name="select_dst_port">
1153 Ports on which departing packets are selected for mirroring.
1156 <column name="select_src_port">
1157 Ports on which arriving packets are selected for mirroring.
1160 <column name="select_vlan">
1161 VLANs on which packets are selected for mirroring. An empty set
1162 selects packets on all VLANs.
1166 <group title="Mirroring Destination Configuration">
1167 <column name="output_port">
1168 <p>Output port for selected packets, if nonempty. Mutually exclusive
1169 with <ref column="output_vlan"/>.</p>
1170 <p>Specifying a port for mirror output reserves that port exclusively
1171 for mirroring. No frames other than those selected for mirroring
1172 will be forwarded to the port, and any frames received on the port
1173 will be discarded.</p>
1174 <p>This type of mirroring is sometimes called SPAN.</p>
1177 <column name="output_vlan">
1178 <p>Output VLAN for selected packets, if nonempty. Mutually exclusive
1179 with <ref column="output_port"/>.</p>
1180 <p>The frames will be sent out all ports that trunk
1181 <ref column="output_vlan"/>, as well as any ports with implicit VLAN
1182 <ref column="output_vlan"/>. When a mirrored frame is sent out a
1183 trunk port, the frame's VLAN tag will be set to
1184 <ref column="output_vlan"/>, replacing any existing tag; when it is
1185 sent out an implicit VLAN port, the frame will not be tagged. This
1186 type of mirroring is sometimes called RSPAN.</p>
1187 <p><em>Please note:</em> Mirroring to a VLAN can disrupt a network that
1188 contains unmanaged switches. Consider an unmanaged physical switch
1189 with two ports: port 1, connected to an end host, and port 2,
1190 connected to an Open vSwitch configured to mirror received packets
1191 into VLAN 123 on port 2. Suppose that the end host sends a packet on
1192 port 1 that the physical switch forwards to port 2. The Open vSwitch
1193 forwards this packet to its destination and then reflects it back on
1194 port 2 in VLAN 123. This reflected packet causes the unmanaged
1195 physical switch to replace the MAC learning table entry, which
1196 correctly pointed to port 1, with one that incorrectly points to port
1197 2. Afterward, the physical switch will direct packets destined for
1198 the end host to the Open vSwitch on port 2, instead of to the end
1199 host on port 1, disrupting connectivity. If mirroring to a VLAN is
1200 desired in this scenario, then the physical switch must be replaced
1201 by one that learns Ethernet addresses on a per-VLAN basis. In
1202 addition, learning should be disabled on the VLAN containing mirrored
1203 traffic. If this is not done then intermediate switches will learn
1204 the MAC address of each end host from the mirrored traffic. If
1205 packets being sent to that end host are also mirrored, then they will
1206 be dropped since the switch will attempt to send them out the input
1207 port. Disabling learning for the VLAN will cause the switch to
1208 correctly send the packet out all ports configured for that VLAN. If
1209 Open vSwitch is being used as an intermediate switch, learning can be
1210 disabled by adding the mirrored VLAN to <ref column="flood_vlans"/>
1211 in the appropriate <ref table="Bridge"/> table or tables.</p>
1215 <group title="Other Features">
1216 <column name="external_ids">
1217 Key-value pairs for use by external frameworks that integrate with Open
1218 vSwitch, rather than by Open vSwitch itself. System integrators should
1219 either use the Open vSwitch development mailing list to coordinate on
1220 common key-value definitions, or choose key names that are likely to be
1221 unique. No common key-value pairs are currently defined.
1226 <table name="Controller" title="OpenFlow controller configuration.">
1227 <p>An OpenFlow controller.</p>
1230 Open vSwitch supports two kinds of OpenFlow controllers:
1234 <dt>Primary controllers</dt>
1237 This is the kind of controller envisioned by the OpenFlow 1.0
1238 specification. Usually, a primary controller implements a network
1239 policy by taking charge of the switch's flow table.
1243 Open vSwitch initiates and maintains persistent connections to
1244 primary controllers, retrying the connection each time it fails or
1245 drops. The <ref table="Bridge" column="fail_mode"/> column in the
1246 <ref table="Bridge"/> table applies to primary controllers.
1250 Open vSwitch permits a bridge to have any number of primary
1251 controllers. When multiple controllers are configured, Open
1252 vSwitch connects to all of them simultaneously. Because
1253 OpenFlow 1.0 does not specify how multiple controllers
1254 coordinate in interacting with a single switch, more than
1255 one primary controller should be specified only if the
1256 controllers are themselves designed to coordinate with each
1257 other. (The Nicira-defined <code>NXT_ROLE</code> OpenFlow
1258 vendor extension may be useful for this.)
1261 <dt>Service controllers</dt>
1264 These kinds of OpenFlow controller connections are intended for
1265 occasional support and maintenance use, e.g. with
1266 <code>ovs-ofctl</code>. Usually a service controller connects only
1267 briefly to inspect or modify some of a switch's state.
1271 Open vSwitch listens for incoming connections from service
1272 controllers. The service controllers initiate and, if necessary,
1273 maintain the connections from their end. The <ref table="Bridge"
1274 column="fail_mode"/> column in the <ref table="Bridge"/> table does
1275 not apply to service controllers.
1279 Open vSwitch supports configuring any number of service controllers.
1285 The <ref column="target"/> determines the type of controller.
1288 <group title="Core Features">
1289 <column name="target">
1290 <p>Connection method for controller.</p>
1292 The following connection methods are currently supported for primary
1296 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1298 <p>The specified SSL <var>port</var> (default: 6633) on the host at
1299 the given <var>ip</var>, which must be expressed as an IP address
1300 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1301 column in the <ref table="Open_vSwitch"/> table must point to a
1302 valid SSL configuration when this form is used.</p>
1303 <p>SSL support is an optional feature that is not always built as
1304 part of Open vSwitch.</p>
1306 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1307 <dd>The specified TCP <var>port</var> (default: 6633) on the host at
1308 the given <var>ip</var>, which must be expressed as an IP address
1309 (not a DNS name).</dd>
1310 <dt><code>discover</code></dt>
1312 <p>Enables controller discovery.</p>
1313 <p>In controller discovery mode, Open vSwitch broadcasts a DHCP
1314 request with vendor class identifier <code>OpenFlow</code> across
1315 all of the bridge's network devices. It will accept any valid
1316 DHCP reply that has the same vendor class identifier and includes
1317 a vendor-specific option with code 1 whose contents are a string
1318 specifying the location of the controller in the same format as
1319 <ref column="target"/>.</p>
1320 <p>The DHCP reply may also, optionally, include a vendor-specific
1321 option with code 2 whose contents are a string specifying the URI
1322 to the base of the OpenFlow PKI
1323 (e.g. <code>http://192.168.0.1/openflow/pki</code>). This URI is
1324 used only for bootstrapping the OpenFlow PKI at initial switch
1325 setup; <code>ovs-vswitchd</code> does not use it at all.</p>
1329 The following connection methods are currently supported for service
1333 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1336 Listens for SSL connections on the specified TCP <var>port</var>
1337 (default: 6633). If <var>ip</var>, which must be expressed as an
1338 IP address (not a DNS name), is specified, then connections are
1339 restricted to the specified local IP address.
1342 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1343 table="Open_vSwitch"/> table must point to a valid SSL
1344 configuration when this form is used.
1346 <p>SSL support is an optional feature that is not always built as
1347 part of Open vSwitch.</p>
1349 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1351 Listens for connections on the specified TCP <var>port</var>
1352 (default: 6633). If <var>ip</var>, which must be expressed as an
1353 IP address (not a DNS name), is specified, then connections are
1354 restricted to the specified local IP address.
1357 <p>When multiple controllers are configured for a single bridge, the
1358 <ref column="target"/> values must be unique. Duplicate
1359 <ref column="target"/> values yield unspecified results.</p>
1362 <column name="connection_mode">
1363 <p>If it is specified, this setting must be one of the following
1364 strings that describes how Open vSwitch contacts this OpenFlow
1365 controller over the network:</p>
1368 <dt><code>in-band</code></dt>
1369 <dd>In this mode, this controller's OpenFlow traffic travels over the
1370 bridge associated with the controller. With this setting, Open
1371 vSwitch allows traffic to and from the controller regardless of the
1372 contents of the OpenFlow flow table. (Otherwise, Open vSwitch
1373 would never be able to connect to the controller, because it did
1374 not have a flow to enable it.) This is the most common connection
1375 mode because it is not necessary to maintain two independent
1377 <dt><code>out-of-band</code></dt>
1378 <dd>In this mode, OpenFlow traffic uses a control network separate
1379 from the bridge associated with this controller, that is, the
1380 bridge does not use any of its own network devices to communicate
1381 with the controller. The control network must be configured
1382 separately, before or after <code>ovs-vswitchd</code> is started.
1386 <p>If not specified, the default is implementation-specific. If
1387 <ref column="target"/> is <code>discover</code>, the connection mode
1388 is always treated as <code>in-band</code> regardless of the actual
1393 <group title="Controller Failure Detection and Handling">
1394 <column name="max_backoff">
1395 Maximum number of milliseconds to wait between connection attempts.
1396 Default is implementation-specific.
1399 <column name="inactivity_probe">
1400 Maximum number of milliseconds of idle time on connection to
1401 controller before sending an inactivity probe message. If Open
1402 vSwitch does not communicate with the controller for the specified
1403 number of seconds, it will send a probe. If a response is not
1404 received for the same additional amount of time, Open vSwitch
1405 assumes the connection has been broken and attempts to reconnect.
1406 Default is implementation-specific.
1410 <group title="OpenFlow Rate Limiting">
1411 <column name="controller_rate_limit">
1412 <p>The maximum rate at which packets in unknown flows will be
1413 forwarded to the OpenFlow controller, in packets per second. This
1414 feature prevents a single bridge from overwhelming the controller.
1415 If not specified, the default is implementation-specific.</p>
1416 <p>In addition, when a high rate triggers rate-limiting, Open
1417 vSwitch queues controller packets for each port and transmits
1418 them to the controller at the configured rate. The number of
1419 queued packets is limited by
1420 the <ref column="controller_burst_limit"/> value. The packet
1421 queue is shared fairly among the ports on a bridge.</p><p>Open
1422 vSwitch maintains two such packet rate-limiters per bridge.
1423 One of these applies to packets sent up to the controller
1424 because they do not correspond to any flow. The other applies
1425 to packets sent up to the controller by request through flow
1426 actions. When both rate-limiters are filled with packets, the
1427 actual rate that packets are sent to the controller is up to
1428 twice the specified rate.</p>
1431 <column name="controller_burst_limit">
1432 In conjunction with <ref column="controller_rate_limit"/>,
1433 the maximum number of unused packet credits that the bridge will
1434 allow to accumulate, in packets. If not specified, the default
1435 is implementation-specific.
1439 <group title="Additional Discovery Configuration">
1440 <p>These values are considered only when <ref column="target"/>
1441 is <code>discover</code>.</p>
1443 <column name="discover_accept_regex">
1445 extended regular expression against which the discovered controller
1446 location is validated. The regular expression is implicitly
1447 anchored at the beginning of the controller location string, as
1448 if it begins with <code>^</code>. If not specified, the default
1449 is implementation-specific.
1452 <column name="discover_update_resolv_conf">
1453 Whether to update <code>/etc/resolv.conf</code> when the
1454 controller is discovered. If not specified, the default
1455 is implementation-specific. Open vSwitch will only modify
1456 <code>/etc/resolv.conf</code> if the DHCP response that it receives
1457 specifies one or more DNS servers.
1461 <group title="Additional In-Band Configuration">
1462 <p>These values are considered only in in-band control mode (see
1463 <ref column="connection_mode"/>) and only when <ref column="target"/>
1464 is not <code>discover</code>. (For controller discovery, the network
1465 configuration obtained via DHCP is used instead.)</p>
1467 <p>When multiple controllers are configured on a single bridge, there
1468 should be only one set of unique values in these columns. If different
1469 values are set for these columns in different controllers, the effect
1472 <column name="local_ip">
1473 The IP address to configure on the local port,
1474 e.g. <code>192.168.0.123</code>. If this value is unset, then
1475 <ref column="local_netmask"/> and <ref column="local_gateway"/> are
1479 <column name="local_netmask">
1480 The IP netmask to configure on the local port,
1481 e.g. <code>255.255.255.0</code>. If <ref column="local_ip"/> is set
1482 but this value is unset, then the default is chosen based on whether
1483 the IP address is class A, B, or C.
1486 <column name="local_gateway">
1487 The IP address of the gateway to configure on the local port, as a
1488 string, e.g. <code>192.168.0.1</code>. Leave this column unset if
1489 this network has no gateway.
1493 <group title="Other Features">
1494 <column name="external_ids">
1495 Key-value pairs for use by external frameworks that integrate with Open
1496 vSwitch, rather than by Open vSwitch itself. System integrators should
1497 either use the Open vSwitch development mailing list to coordinate on
1498 common key-value definitions, or choose key names that are likely to be
1499 unique. No common key-value pairs are currently defined.
1504 <table name="Manager" title="OVSDB management connection.">
1506 Configuration for a database connection to an Open vSwitch database
1511 This table primarily configures the Open vSwitch database
1512 (<code>ovsdb-server</code>), not the Open vSwitch switch
1513 (<code>ovs-vswitchd</code>). The switch does read the table to determine
1514 what connections should be treated as in-band.
1518 The Open vSwitch database server can initiate and maintain active
1519 connections to remote clients. It can also listen for database
1523 <group title="Core Features">
1524 <column name="target">
1525 <p>Connection method for managers.</p>
1527 The following connection methods are currently supported:
1530 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1533 The specified SSL <var>port</var> (default: 6632) on the host at
1534 the given <var>ip</var>, which must be expressed as an IP address
1535 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1536 column in the <ref table="Open_vSwitch"/> table must point to a
1537 valid SSL configuration when this form is used.
1540 SSL support is an optional feature that is not always built as
1541 part of Open vSwitch.
1545 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1547 The specified TCP <var>port</var> (default: 6632) on the host at
1548 the given <var>ip</var>, which must be expressed as an IP address
1551 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1554 Listens for SSL connections on the specified TCP <var>port</var>
1555 (default: 6632). If <var>ip</var>, which must be expressed as an
1556 IP address (not a DNS name), is specified, then connections are
1557 restricted to the specified local IP address.
1560 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1561 table="Open_vSwitch"/> table must point to a valid SSL
1562 configuration when this form is used.
1565 SSL support is an optional feature that is not always built as
1566 part of Open vSwitch.
1569 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1571 Listens for connections on the specified TCP <var>port</var>
1572 (default: 6632). If <var>ip</var>, which must be expressed as an
1573 IP address (not a DNS name), is specified, then connections are
1574 restricted to the specified local IP address.
1577 <p>When multiple managers are configured, the <ref column="target"/>
1578 values must be unique. Duplicate <ref column="target"/> values yield
1579 unspecified results.</p>
1582 <column name="connection_mode">
1584 If it is specified, this setting must be one of the following strings
1585 that describes how Open vSwitch contacts this OVSDB client over the
1590 <dt><code>in-band</code></dt>
1592 In this mode, this connection's traffic travels over a bridge
1593 managed by Open vSwitch. With this setting, Open vSwitch allows
1594 traffic to and from the client regardless of the contents of the
1595 OpenFlow flow table. (Otherwise, Open vSwitch would never be able
1596 to connect to the client, because it did not have a flow to enable
1597 it.) This is the most common connection mode because it is not
1598 necessary to maintain two independent networks.
1600 <dt><code>out-of-band</code></dt>
1602 In this mode, the client's traffic uses a control network separate
1603 from that managed by Open vSwitch, that is, Open vSwitch does not
1604 use any of its own network devices to communicate with the client.
1605 The control network must be configured separately, before or after
1606 <code>ovs-vswitchd</code> is started.
1611 If not specified, the default is implementation-specific.
1616 <group title="Client Failure Detection and Handling">
1617 <column name="max_backoff">
1618 Maximum number of milliseconds to wait between connection attempts.
1619 Default is implementation-specific.
1622 <column name="inactivity_probe">
1623 Maximum number of milliseconds of idle time on connection to the client
1624 before sending an inactivity probe message. If Open vSwitch does not
1625 communicate with the client for the specified number of seconds, it
1626 will send a probe. If a response is not received for the same
1627 additional amount of time, Open vSwitch assumes the connection has been
1628 broken and attempts to reconnect. Default is implementation-specific.
1632 <group title="Other Features">
1633 <column name="external_ids">
1634 Key-value pairs for use by external frameworks that integrate with Open
1635 vSwitch, rather than by Open vSwitch itself. System integrators should
1636 either use the Open vSwitch development mailing list to coordinate on
1637 common key-value definitions, or choose key names that are likely to be
1638 unique. No common key-value pairs are currently defined.
1643 <table name="NetFlow">
1644 A NetFlow target. NetFlow is a protocol that exports a number of
1645 details about terminating IP flows, such as the principals involved
1648 <column name="targets">
1649 NetFlow targets in the form
1650 <code><var>ip</var>:<var>port</var></code>. The <var>ip</var>
1651 must be specified numerically, not as a DNS name.
1654 <column name="engine_id">
1655 Engine ID to use in NetFlow messages. Defaults to datapath index
1659 <column name="engine_type">
1660 Engine type to use in NetFlow messages. Defaults to datapath
1661 index if not specified.
1664 <column name="active_timeout">
1665 The interval at which NetFlow records are sent for flows that are
1666 still active, in seconds. A value of <code>0</code> requests the
1667 default timeout (currently 600 seconds); a value of <code>-1</code>
1668 disables active timeouts.
1671 <column name="add_id_to_interface">
1672 <p>If this column's value is <code>false</code>, the ingress and egress
1673 interface fields of NetFlow flow records are derived from OpenFlow port
1674 numbers. When it is <code>true</code>, the 7 most significant bits of
1675 these fields will be replaced by the least significant 7 bits of the
1676 engine id. This is useful because many NetFlow collectors do not
1677 expect multiple switches to be sending messages from the same host, so
1678 they do not store the engine information which could be used to
1679 disambiguate the traffic.</p>
1680 <p>When this option is enabled, a maximum of 508 ports are supported.</p>
1683 <column name="external_ids">
1684 Key-value pairs for use by external frameworks that integrate with Open
1685 vSwitch, rather than by Open vSwitch itself. System integrators should
1686 either use the Open vSwitch development mailing list to coordinate on
1687 common key-value definitions, or choose key names that are likely to be
1688 unique. No common key-value pairs are currently defined.
1693 SSL configuration for an Open_vSwitch.
1695 <column name="private_key">
1696 Name of a PEM file containing the private key used as the switch's
1697 identity for SSL connections to the controller.
1700 <column name="certificate">
1701 Name of a PEM file containing a certificate, signed by the
1702 certificate authority (CA) used by the controller and manager,
1703 that certifies the switch's private key, identifying a trustworthy
1707 <column name="ca_cert">
1708 Name of a PEM file containing the CA certificate used to verify
1709 that the switch is connected to a trustworthy controller.
1712 <column name="bootstrap_ca_cert">
1713 If set to <code>true</code>, then Open vSwitch will attempt to
1714 obtain the CA certificate from the controller on its first SSL
1715 connection and save it to the named PEM file. If it is successful,
1716 it will immediately drop the connection and reconnect, and from then
1717 on all SSL connections must be authenticated by a certificate signed
1718 by the CA certificate thus obtained. <em>This option exposes the
1719 SSL connection to a man-in-the-middle attack obtaining the initial
1720 CA certificate.</em> It may still be useful for bootstrapping.
1723 <column name="external_ids">
1724 Key-value pairs for use by external frameworks that integrate with Open
1725 vSwitch, rather than by Open vSwitch itself. System integrators should
1726 either use the Open vSwitch development mailing list to coordinate on
1727 common key-value definitions, or choose key names that are likely to be
1728 unique. No common key-value pairs are currently defined.
1732 <table name="sFlow">
1733 <p>An sFlow(R) target. sFlow is a protocol for remote monitoring
1736 <column name="agent">
1737 Name of the network device whose IP address should be reported as the
1738 ``agent address'' to collectors. If not specified, the IP address
1739 defaults to the <ref table="Controller" column="local_ip"/> in the
1740 collector's <ref table="Controller"/>. If an agent IP address cannot be
1741 determined either way, sFlow is disabled.
1744 <column name="header">
1745 Number of bytes of a sampled packet to send to the collector.
1746 If not specified, the default is 128 bytes.
1749 <column name="polling">
1750 Polling rate in seconds to send port statistics to the collector.
1751 If not specified, defaults to 30 seconds.
1754 <column name="sampling">
1755 Rate at which packets should be sampled and sent to the collector.
1756 If not specified, defaults to 400, which means one out of 400
1757 packets, on average, will be sent to the collector.
1760 <column name="targets">
1761 sFlow targets in the form
1762 <code><var>ip</var>:<var>port</var></code>.
1765 <column name="external_ids">
1766 Key-value pairs for use by external frameworks that integrate with Open
1767 vSwitch, rather than by Open vSwitch itself. System integrators should
1768 either use the Open vSwitch development mailing list to coordinate on
1769 common key-value definitions, or choose key names that are likely to be
1770 unique. No common key-value pairs are currently defined.
1774 <table name="Capability">
1775 <p>Records in this table describe functionality supported by the hardware
1776 and software platform on which this Open vSwitch is based. Clients
1777 should not modify this table.</p>
1779 <p>A record in this table is meaningful only if it is referenced by the
1780 <ref table="Open_vSwitch" column="capabilities"/> column in the
1781 <ref table="Open_vSwitch"/> table. The key used to reference it, called
1782 the record's ``category,'' determines the meanings of the
1783 <ref column="details"/> column. The following general forms of
1784 categories are currently defined:</p>
1787 <dt><code>qos-<var>type</var></code></dt>
1788 <dd><var>type</var> is supported as the value for
1789 <ref column="type" table="QoS"/> in the <ref table="QoS"/> table.
1793 <column name="details">
1794 <p>Key-value pairs that describe capabilities. The meaning of the pairs
1795 depends on the category key that the <ref table="Open_vSwitch"
1796 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
1797 uses to reference this record, as described above.</p>
1799 <p>The presence of a record for category <code>qos-<var>type</var></code>
1800 indicates that the switch supports <var>type</var> as the value of
1801 the <ref table="QoS" column="type"/> column in the <ref table="QoS"/>
1802 table. The following key-value pairs are defined to further describe
1803 QoS capabilities:</p>
1806 <dt><code>n-queues</code></dt>
1807 <dd>Number of supported queues, as a positive integer. Keys in the
1808 <ref table="QoS" column="queues"/> column for <ref table="QoS"/>
1809 records whose <ref table="QoS" column="type"/> value
1810 equals <var>type</var> must range between 0 and this value minus one,