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
372 <dt><code>in-band-queue</code></dt>
374 A queue ID as a nonnegative integer. This sets the OpenFlow queue
375 ID that will be used by flows set up by in-band control on this
376 bridge. If unset, or if the port used by an in-band control flow
377 does not have QoS configured, or if the port does not have a queue
378 with the specified ID, the default queue is used instead.
385 <table name="Port" table="Port or bond configuration.">
386 <p>A port within a <ref table="Bridge"/>.</p>
387 <p>Most commonly, a port has exactly one ``interface,'' pointed to by its
388 <ref column="interfaces"/> column. Such a port logically
389 corresponds to a port on a physical Ethernet switch. A port
390 with more than one interface is a ``bonded port'' (see
391 <ref group="Bonding Configuration"/>).</p>
392 <p>Some properties that one might think as belonging to a port are actually
393 part of the port's <ref table="Interface"/> members.</p>
396 Port name. Should be alphanumeric and no more than about 8
397 bytes long. May be the same as the interface name, for
398 non-bonded ports. Must otherwise be unique among the names of
399 ports, interfaces, and bridges on a host.
402 <column name="interfaces">
403 The port's interfaces. If there is more than one, this is a
407 <group title="VLAN Configuration">
408 <p>A bridge port must be configured for VLANs in one of two
409 mutually exclusive ways:
411 <li>A ``trunk port'' has an empty value for <ref
412 column="tag"/>. Its <ref column="trunks"/> value may be
413 empty or non-empty.</li>
414 <li>An ``implicitly tagged VLAN port'' or ``access port''
415 has an nonempty value for <ref column="tag"/>. Its
416 <ref column="trunks"/> value must be empty.</li>
418 If <ref column="trunks"/> and <ref column="tag"/> are both
419 nonempty, the configuration is ill-formed.
424 If this is an access port (see above), the port's implicitly
425 tagged VLAN. Must be empty if this is a trunk port.
428 Frames arriving on trunk ports will be forwarded to this
429 port only if they are tagged with the given VLAN (or, if
430 <ref column="tag"/> is 0, then if they lack a VLAN header).
431 Frames arriving on other access ports will be forwarded to
432 this port only if they have the same <ref column="tag"/>
433 value. Frames forwarded to this port will not have an
437 When a frame with a 802.1Q header that indicates a nonzero
438 VLAN is received on an access port, it is discarded.
442 <column name="trunks">
444 If this is a trunk port (see above), the 802.1Q VLAN(s) that
445 this port trunks; if it is empty, then the port trunks all
446 VLANs. Must be empty if this is an access port.
449 Frames arriving on trunk ports are dropped if they are not
450 in one of the specified VLANs. For this purpose, packets
451 that have no VLAN header are treated as part of VLAN 0.
456 <group title="Bonding Configuration">
457 <p>A port that has more than one interface is a ``bonded port.''
458 Bonding allows for load balancing and fail-over. Open vSwitch
459 supports ``source load balancing'' (SLB) bonding, which
460 assigns flows to slaves based on source MAC address and output VLAN,
461 with periodic rebalancing as traffic patterns change. This form of
462 bonding does not require 802.3ad or other special support from the
463 upstream switch to which the slave devices are connected.</p>
465 <p>These columns apply only to bonded ports. Their values are
466 otherwise ignored.</p>
468 <column name="bond_updelay">
469 <p>For a bonded port, the number of milliseconds for which carrier must
470 stay up on an interface before the interface is considered to be up.
471 Specify <code>0</code> to enable the interface immediately.</p>
472 <p>This setting is honored only when at least one bonded interface is
473 already enabled. When no interfaces are enabled, then the first bond
474 interface to come up is enabled immediately.</p>
477 <column name="bond_downdelay">
478 For a bonded port, the number of milliseconds for which carrier must
479 stay down on an interface before the interface is considered to be
480 down. Specify <code>0</code> to disable the interface immediately.
483 <column name="bond_fake_iface">
484 For a bonded port, whether to create a fake internal interface with the
485 name of the port. Use only for compatibility with legacy software that
490 <group title="Other Features">
492 Quality of Service configuration for this port.
496 The MAC address to use for this port for the purpose of choosing the
497 bridge's MAC address. This column does not necessarily reflect the
498 port's actual MAC address, nor will setting it change the port's actual
502 <column name="fake_bridge">
503 Does this port represent a sub-bridge for its tagged VLAN within the
504 Bridge? See ovs-vsctl(8) for more information.
507 <column name="external_ids">
509 Key-value pairs for use by external frameworks that integrate with
510 Open vSwitch, rather than by Open vSwitch itself. System integrators
511 should either use the Open vSwitch development mailing list to
512 coordinate on common key-value definitions, or choose key names that
513 are likely to be unique.
516 No key-value pairs native to <ref table="Port"/> are currently
517 defined. For fake bridges (see the <ref column="fake_bridge"/>
518 column), external IDs for the fake bridge are defined here by
519 prefixing a <ref table="Bridge"/> <ref table="Bridge"
520 column="external_ids"/> key with <code>fake-bridge-</code>,
521 e.g. <code>fake-bridge-xs-network-uuids</code>.
525 <column name="other_config">
526 Key-value pairs for configuring rarely used port features. The
527 currently defined key-value pairs are:
529 <dt><code>hwaddr</code></dt>
530 <dd>An Ethernet address in the form
531 <code><var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var></code>.</dd>
532 <dt><code>bond-rebalance-interval</code></dt>
533 <dd>For a bonded port, the number of milliseconds between
534 successive attempts to rebalance the bond, that is, to
535 move source MACs and their flows from one interface on
536 the bond to another in an attempt to keep usage of each
537 interface roughly equal. The default is 10000 (10
538 seconds), and the minimum is 1000 (1 second).</dd>
544 <table name="Interface" title="One physical network device in a Port.">
545 An interface within a <ref table="Port"/>.
547 <group title="Core Features">
549 Interface name. Should be alphanumeric and no more than about 8 bytes
550 long. May be the same as the port name, for non-bonded ports. Must
551 otherwise be unique among the names of ports, interfaces, and bridges
556 <p>Ethernet address to set for this interface. If unset then the
557 default MAC address is used:</p>
559 <li>For the local interface, the default is the lowest-numbered MAC
560 address among the other bridge ports, either the value of the
561 <ref table="Port" column="mac"/> in its <ref table="Port"/> record,
562 if set, or its actual MAC (for bonded ports, the MAC of its slave
563 whose name is first in alphabetical order). Internal ports and
564 bridge ports that are used as port mirroring destinations (see the
565 <ref table="Mirror"/> table) are ignored.</li>
566 <li>For other internal interfaces, the default MAC is randomly
568 <li>External interfaces typically have a MAC address associated with
571 <p>Some interfaces may not have a software-controllable MAC
575 <column name="ofport">
576 <p>OpenFlow port number for this interface. Unlike most columns, this
577 column's value should be set only by Open vSwitch itself. Other
578 clients should set this column to an empty set (the default) when
579 creating an <ref table="Interface"/>.</p>
580 <p>Open vSwitch populates this column when the port number becomes
581 known. If the interface is successfully added,
582 <ref column="ofport"/> will be set to a number between 1 and 65535
583 (generally either in the range 1 to 65279, inclusive, or 65534, the
584 port number for the OpenFlow ``local port''). If the interface
585 cannot be added then Open vSwitch sets this column
590 <group title="System-Specific Details">
592 The interface type, one of:
594 <dt><code>system</code></dt>
595 <dd>An ordinary network device, e.g. <code>eth0</code> on Linux.
596 Sometimes referred to as ``external interfaces'' since they are
597 generally connected to hardware external to that on which the Open
598 vSwitch is running. The empty string is a synonym for
599 <code>system</code>.</dd>
600 <dt><code>internal</code></dt>
601 <dd>A simulated network device that sends and receives traffic. An
602 internal interface whose <ref column="name"/> is the same as its
603 bridge's <ref table="Open_vSwitch" column="name"/> is called the
604 ``local interface.'' It does not make sense to bond an internal
605 interface, so the terms ``port'' and ``interface'' are often used
606 imprecisely for internal interfaces.</dd>
607 <dt><code>tap</code></dt>
608 <dd>A TUN/TAP device managed by Open vSwitch.</dd>
609 <dt><code>gre</code></dt>
610 <dd>An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
611 tunnel. Each tunnel must be uniquely identified by the
612 combination of <code>remote_ip</code>, <code>local_ip</code>, and
613 <code>in_key</code>. Note that if two ports are defined that are
614 the same except one has an optional identifier and the other does
615 not, the more specific one is matched first. <code>in_key</code>
616 is considered more specific than <code>local_ip</code> if a port
617 defines one and another port defines the other. The following
618 options may be specified in the <ref column="options"/> column:
620 <dt><code>remote_ip</code></dt>
621 <dd>Required. The tunnel endpoint.</dd>
624 <dt><code>local_ip</code></dt>
625 <dd>Optional. The destination IP that received packets must
626 match. Default is to match all addresses.</dd>
629 <dt><code>in_key</code></dt>
630 <dd>Optional. The GRE key that received packets must contain.
631 It may either be a 32-bit number (no key and a key of 0 are
632 treated as equivalent) or the word <code>flow</code>. If
633 <code>flow</code> is specified then any key will be accepted
634 and the key will be placed in the <code>tun_id</code> field
635 for matching in the flow table. The ovs-ofctl manual page
636 contains additional information about matching fields in
637 OpenFlow flows. Default is no key.</dd>
640 <dt><code>out_key</code></dt>
641 <dd>Optional. The GRE key to be set on outgoing packets. It may
642 either be a 32-bit number or the word <code>flow</code>. If
643 <code>flow</code> is specified then the key may be set using
644 the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0
645 is used in the absence of an action). The ovs-ofctl manual
646 page contains additional information about the Nicira OpenFlow
647 vendor extensions. Default is no key.</dd>
650 <dt><code>key</code></dt>
651 <dd>Optional. Shorthand to set <code>in_key</code> and
652 <code>out_key</code> at the same time.</dd>
655 <dt><code>tos</code></dt>
656 <dd>Optional. The value of the ToS bits to be set on the
657 encapsulating packet. It may also be the word
658 <code>inherit</code>, in which case the ToS will be copied from
659 the inner packet if it is IPv4 or IPv6 (otherwise it will be
660 0). Note that the ECN fields are always inherited. Default is
664 <dt><code>ttl</code></dt>
665 <dd>Optional. The TTL to be set on the encapsulating packet.
666 It may also be the word <code>inherit</code>, in which case the
667 TTL will be copied from the inner packet if it is IPv4 or IPv6
668 (otherwise it will be the system default, typically 64).
669 Default is the system default TTL.</dd>
672 <dt><code>csum</code></dt>
673 <dd>Optional. Compute GRE checksums on outgoing packets.
674 Checksums present on incoming packets will be validated
675 regardless of this setting. Note that GRE checksums
676 impose a significant performance penalty as they cover the
677 entire packet. As the contents of the packet is typically
678 covered by L3 and L4 checksums, this additional checksum only
679 adds value for the GRE and encapsulated Ethernet headers.
680 Default is disabled, set to <code>true</code> to enable.</dd>
683 <dt><code>pmtud</code></dt>
684 <dd>Optional. Enable tunnel path MTU discovery. If enabled
685 ``ICMP destination unreachable - fragmentation'' needed
686 messages will be generated for IPv4 packets with the DF bit set
687 and IPv6 packets above the minimum MTU if the packet size
688 exceeds the path MTU minus the size of the tunnel headers. It
689 also forces the encapsulating packet DF bit to be set (it is
690 always set if the inner packet implies path MTU discovery).
691 Note that this option causes behavior that is typically
692 reserved for routers and therefore is not entirely in
693 compliance with the IEEE 802.1D specification for bridges.
694 Default is enabled, set to <code>false</code> to disable.</dd>
697 <dt><code>header_cache</code></dt>
698 <dd>Optional. Enable caching of tunnel headers and the output
699 path. This can lead to a significant performance increase
700 without changing behavior. In general it should not be
701 necessary to adjust this setting. However, the caching can
702 bypass certain components of the IP stack (such as IP tables)
703 and it may be useful to disable it if these features are
704 required or as a debugging measure. Default is enabled, set to
705 <code>false</code> to disable. If IPsec is enabled through the
706 <ref column="other_config"/> parameters, header caching will be
707 automatically disabled.</dd>
710 <dt><code>capwap</code></dt>
711 <dd>Ethernet tunneling over the UDP transport portion of CAPWAP
712 (RFC 5415). This allows interoperability with certain switches
713 where GRE is not available. Note that only the tunneling component
714 of the protocol is implemented. Due to the non-standard use of
715 CAPWAP, UDP ports 58881 and 58882 are used as the source and
716 destinations ports respectivedly. Each tunnel must be uniquely
717 identified by the combination of <code>remote_ip</code> and
718 <code>local_ip</code>. If two ports are defined that are the same
719 except one includes <code>local_ip</code> and the other does not,
720 the more specific one is matched first. CAPWAP support is not
721 available on all platforms. Currently it is only supported in the
722 Linux kernel module with kernel versions >= 2.6.25. The following
723 options may be specified in the <ref column="options"/> column:
725 <dt><code>remote_ip</code></dt>
726 <dd>Required. The tunnel endpoint.</dd>
729 <dt><code>local_ip</code></dt>
730 <dd>Optional. The destination IP that received packets must
731 match. Default is to match all addresses.</dd>
734 <dt><code>tos</code></dt>
735 <dd>Optional. The value of the ToS bits to be set on the
736 encapsulating packet. It may also be the word
737 <code>inherit</code>, in which case the ToS will be copied from
738 the inner packet if it is IPv4 or IPv6 (otherwise it will be
739 0). Note that the ECN fields are always inherited. Default is
743 <dt><code>ttl</code></dt>
744 <dd>Optional. The TTL to be set on the encapsulating packet.
745 It may also be the word <code>inherit</code>, in which case the
746 TTL will be copied from the inner packet if it is IPv4 or IPv6
747 (otherwise it will be the system default, typically 64).
748 Default is the system default TTL.</dd>
751 <dt><code>pmtud</code></dt>
752 <dd>Optional. Enable tunnel path MTU discovery. If enabled
753 ``ICMP destination unreachable - fragmentation'' needed
754 messages will be generated for IPv4 packets with the DF bit set
755 and IPv6 packets above the minimum MTU if the packet size
756 exceeds the path MTU minus the size of the tunnel headers. It
757 also forces the encapsulating packet DF bit to be set (it is
758 always set if the inner packet implies path MTU discovery).
759 Note that this option causes behavior that is typically
760 reserved for routers and therefore is not entirely in
761 compliance with the IEEE 802.1D specification for bridges.
762 Default is enabled, set to <code>false</code> to disable.</dd>
765 <dt><code>header_cache</code></dt>
766 <dd>Optional. Enable caching of tunnel headers and the output
767 path. This can lead to a significant performance increase
768 without changing behavior. In general it should not be
769 necessary to adjust this setting. However, the caching can
770 bypass certain components of the IP stack (such as IP tables)
771 and it may be useful to disable it if these features are
772 required or as a debugging measure. Default is enabled, set to
773 <code>false</code> to disable.</dd>
776 <dt><code>patch</code></dt>
779 A pair of virtual devices that act as a patch cable. The <ref
780 column="options"/> column must have the following key-value pair:
783 <dt><code>peer</code></dt>
785 The <ref column="name"/> of the <ref table="Interface"/> for
786 the other side of the patch. The named <ref
787 table="Interface"/>'s own <code>peer</code> option must specify
788 this <ref table="Interface"/>'s name. That is, the two patch
789 interfaces must have reversed <ref column="name"/> and
790 <code>peer</code> values.
797 <column name="options">
798 Configuration options whose interpretation varies based on
799 <ref column="type"/>.
802 <column name="status">
804 Key-value pairs that report port status. Supported status
805 values are <code>type</code>-dependent.
807 <p>The only currently defined key-value pair is:</p>
809 <dt><code>source_ip</code></dt>
810 <dd>The source IP address used for an IPv4 tunnel end-point,
811 such as <code>gre</code> or <code>capwap</code>. Not
812 supported by all implementations.</dd>
817 <group title="Ingress Policing">
819 These settings control ingress policing for packets received on this
820 interface. On a physical interface, this limits the rate at which
821 traffic is allowed into the system from the outside; on a virtual
822 interface (one connected to a virtual machine), this limits the rate at
823 which the VM is able to transmit.
826 Policing is a simple form of quality-of-service that simply drops
827 packets received in excess of the configured rate. Due to its
828 simplicity, policing is usually less accurate and less effective than
829 egress QoS (which is configured using the <ref table="QoS"/> and <ref
830 table="Queue"/> tables).
833 Policing is currently implemented only on Linux. The Linux
834 implementation uses a simple ``token bucket'' approach:
838 The size of the bucket corresponds to <ref
839 column="ingress_policing_burst"/>. Initially the bucket is full.
842 Whenever a packet is received, its size (converted to tokens) is
843 compared to the number of tokens currently in the bucket. If the
844 required number of tokens are available, they are removed and the
845 packet is forwarded. Otherwise, the packet is dropped.
848 Whenever it is not full, the bucket is refilled with tokens at the
849 rate specified by <ref column="ingress_policing_rate"/>.
853 Policing interacts badly with some network protocols, and especially
854 with fragmented IP packets. Suppose that there is enough network
855 activity to keep the bucket nearly empty all the time. Then this token
856 bucket algorithm will forward a single packet every so often, with the
857 period depending on packet size and on the configured rate. All of the
858 fragments of an IP packets are normally transmitted back-to-back, as a
859 group. In such a situation, therefore, only one of these fragments
860 will be forwarded and the rest will be dropped. IP does not provide
861 any way for the intended recipient to ask for only the remaining
862 fragments. In such a case there are two likely possibilities for what
863 will happen next: either all of the fragments will eventually be
864 retransmitted (as TCP will do), in which case the same problem will
865 recur, or the sender will not realize that its packet has been dropped
866 and data will simply be lost (as some UDP-based protocols will do).
867 Either way, it is possible that no forward progress will ever occur.
869 <column name="ingress_policing_rate">
871 Maximum rate for data received on this interface, in kbps. Data
872 received faster than this rate is dropped. Set to <code>0</code>
873 (the default) to disable policing.
877 <column name="ingress_policing_burst">
878 <p>Maximum burst size for data received on this interface, in kb. The
879 default burst size if set to <code>0</code> is 1000 kb. This value
880 has no effect if <ref column="ingress_policing_rate"/>
881 is <code>0</code>.</p>
883 Specifying a larger burst size lets the algorithm be more forgiving,
884 which is important for protocols like TCP that react severely to
885 dropped packets. The burst size should be at least the size of the
886 interface's MTU. Specifying a value that is numerically at least as
887 large as 10% of <ref column="ingress_policing_rate"/> helps TCP come
888 closer to achieving the full rate.
893 <group title="Other Features">
895 <column name="monitor">
896 Connectivity monitor configuration for this interface.
899 <column name="external_ids">
900 Key-value pairs for use by external frameworks that integrate
901 with Open vSwitch, rather than by Open vSwitch itself. System
902 integrators should either use the Open vSwitch development
903 mailing list to coordinate on common key-value definitions, or
904 choose key names that are likely to be unique. The currently
905 defined common key-value pairs are:
907 <dt><code>attached-mac</code></dt>
909 The MAC address programmed into the ``virtual hardware'' for this
910 interface, in the form
911 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>.
912 For Citrix XenServer, this is the value of the <code>MAC</code>
913 field in the VIF record for this interface.</dd>
914 <dt><code>iface-id</code></dt>
915 <dd>A system-unique identifier for the interface. On XenServer,
916 this will commonly be the same as <code>xs-vif-uuid</code>.</dd>
919 Additionally the following key-value pairs specifically
920 apply to an interface that represents a virtual Ethernet interface
921 connected to a virtual machine. These key-value pairs should not be
922 present for other types of interfaces. Keys whose names end
923 in <code>-uuid</code> have values that uniquely identify the entity
924 in question. For a Citrix XenServer hypervisor, these values are
925 UUIDs in RFC 4122 format. Other hypervisors may use other
928 <p>The currently defined key-value pairs for XenServer are:</p>
930 <dt><code>xs-vif-uuid</code></dt>
931 <dd>The virtual interface associated with this interface.</dd>
932 <dt><code>xs-network-uuid</code></dt>
933 <dd>The virtual network to which this interface is attached.</dd>
934 <dt><code>xs-vm-uuid</code></dt>
935 <dd>The VM to which this interface belongs.</dd>
939 <column name="other_config">
940 Key-value pairs for rarely used interface features. Currently,
941 the only keys are for configuring GRE-over-IPsec, which is only
942 available through the <code>openvswitch-ipsec</code> package for
943 Debian. The currently defined key-value pairs are:
945 <dt><code>ipsec_local_ip</code></dt>
946 <dd>Required key for GRE-over-IPsec interfaces. Additionally,
947 the <ref column="type"/> must be <code>gre</code> and the
948 <code>ipsec_psk</code> <ref column="other_config"/> key must
949 be set. The <code>in_key</code>, <code>out_key</code>, and
950 <code>key</code> <ref column="options"/> must not be
952 <dt><code>ipsec_psk</code></dt>
953 <dd>Required key for GRE-over-IPsec interfaces. Specifies a
954 pre-shared key for authentication that must be identical on
955 both sides of the tunnel. Additionally, the
956 <code>ipsec_local_ip</code> key must also be set.</dd>
960 <column name="statistics">
962 Key-value pairs that report interface statistics. The current
963 implementation updates these counters periodically. In the future,
964 we plan to, instead, update them when an interface is created, when
965 they are queried (e.g. using an OVSDB <code>select</code> operation),
966 and just before an interface is deleted due to virtual interface
967 hot-unplug or VM shutdown, and perhaps at other times, but not on any
968 regular periodic basis.</p>
970 The currently defined key-value pairs are listed below. These are
971 the same statistics reported by OpenFlow in its <code>struct
972 ofp_port_stats</code> structure. If an interface does not support a
973 given statistic, then that pair is omitted.</p>
976 Successful transmit and receive counters:
978 <dt><code>rx_packets</code></dt>
979 <dd>Number of received packets.</dd>
980 <dt><code>rx_bytes</code></dt>
981 <dd>Number of received bytes.</dd>
982 <dt><code>tx_packets</code></dt>
983 <dd>Number of transmitted packets.</dd>
984 <dt><code>tx_bytes</code></dt>
985 <dd>Number of transmitted bytes.</dd>
991 <dt><code>rx_dropped</code></dt>
992 <dd>Number of packets dropped by RX.</dd>
993 <dt><code>rx_frame_err</code></dt>
994 <dd>Number of frame alignment errors.</dd>
995 <dt><code>rx_over_err</code></dt>
996 <dd>Number of packets with RX overrun.</dd>
997 <dt><code>rx_crc_err</code></dt>
998 <dd>Number of CRC errors.</dd>
999 <dt><code>rx_errors</code></dt>
1001 Total number of receive errors, greater than or equal
1002 to the sum of the above.
1009 <dt><code>tx_dropped</code></dt>
1010 <dd>Number of packets dropped by TX.</dd>
1011 <dt><code>collisions</code></dt>
1012 <dd>Number of collisions.</dd>
1013 <dt><code>tx_errors</code></dt>
1015 Total number of transmit errors, greater
1016 than or equal to the sum of the above.
1025 <table name="QoS" title="Quality of Service configuration">
1026 <p>Quality of Service (QoS) configuration for each Port that
1029 <column name="type">
1030 <p>The type of QoS to implement. The <ref table="Open_vSwitch"
1031 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
1032 identifies the types that a switch actually supports. The currently
1033 defined types are listed below:</p>
1035 <dt><code>linux-htb</code></dt>
1037 Linux ``hierarchy token bucket'' classifier. See tc-htb(8) (also at
1038 <code>http://linux.die.net/man/8/tc-htb</code>) and the HTB manual
1039 (<code>http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm</code>)
1040 for information on how this classifier works and how to configure it.
1044 <dt><code>linux-hfsc</code></dt>
1046 Linux "Hierarchical Fair Service Curve" classifier.
1047 See <code>http://linux-ip.net/articles/hfsc.en/</code> for
1048 information on how this classifier works.
1053 <column name="queues">
1054 <p>A map from queue numbers to <ref table="Queue"/> records. The
1055 supported range of queue numbers depend on <ref column="type"/>. The
1056 queue numbers are the same as the <code>queue_id</code> used in
1057 OpenFlow in <code>struct ofp_action_enqueue</code> and other
1058 structures. Queue 0 is used by OpenFlow output actions that do not
1059 specify a specific queue.</p>
1062 <column name="other_config">
1063 <p>Key-value pairs for configuring QoS features that depend on
1064 <ref column="type"/>.</p>
1065 <p>The <code>linux-htb</code> and <code>linux-hfsc</code> classes support
1066 the following key-value pairs:</p>
1068 <dt><code>max-rate</code></dt>
1069 <dd>Maximum rate shared by all queued traffic, in bit/s.
1070 Optional. If not specified, for physical interfaces, the
1071 default is the link rate. For other interfaces or if the
1072 link rate cannot be determined, the default is currently 100
1077 <column name="external_ids">
1078 Key-value pairs for use by external frameworks that integrate with Open
1079 vSwitch, rather than by Open vSwitch itself. System integrators should
1080 either use the Open vSwitch development mailing list to coordinate on
1081 common key-value definitions, or choose key names that are likely to be
1082 unique. No common key-value pairs are currently defined.
1086 <table name="Queue" title="QoS output queue.">
1087 <p>A configuration for a port output queue, used in configuring Quality of
1088 Service (QoS) features. May be referenced by <ref column="queues"
1089 table="QoS"/> column in <ref table="QoS"/> table.</p>
1091 <column name="other_config">
1092 <p>Key-value pairs for configuring the output queue. The supported
1093 key-value pairs and their meanings depend on the <ref column="type"/>
1094 of the <ref column="QoS"/> records that reference this row.</p>
1095 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1096 column="type"/> of <code>min-rate</code> are:</p>
1098 <dt><code>min-rate</code></dt>
1099 <dd>Minimum guaranteed bandwidth, in bit/s. Required. The
1100 floor value is 1500 bytes/s (12,000 bit/s).</dd>
1102 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1103 column="type"/> of <code>linux-htb</code> are:</p>
1105 <dt><code>min-rate</code></dt>
1106 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1107 <dt><code>max-rate</code></dt>
1108 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1109 queue's rate will not be allowed to exceed the specified value, even
1110 if excess bandwidth is available. If unspecified, defaults to no
1112 <dt><code>burst</code></dt>
1113 <dd>Burst size, in bits. This is the maximum amount of ``credits''
1114 that a queue can accumulate while it is idle. Optional. Details of
1115 the <code>linux-htb</code> implementation require a minimum burst
1116 size, so a too-small <code>burst</code> will be silently
1118 <dt><code>priority</code></dt>
1119 <dd>A nonnegative 32-bit integer. Defaults to 0 if
1120 unspecified. A queue with a smaller <code>priority</code>
1121 will receive all the excess bandwidth that it can use before
1122 a queue with a larger value receives any. Specific priority
1123 values are unimportant; only relative ordering matters.</dd>
1125 <p>The key-value pairs defined for <ref table="QoS"/> <ref table="QoS"
1126 column="type"/> of <code>linux-hfsc</code> are:</p>
1128 <dt><code>min-rate</code></dt>
1129 <dd>Minimum guaranteed bandwidth, in bit/s. Required.</dd>
1130 <dt><code>max-rate</code></dt>
1131 <dd>Maximum allowed bandwidth, in bit/s. Optional. If specified, the
1132 queue's rate will not be allowed to exceed the specified value, even
1133 if excess bandwidth is available. If unspecified, defaults to no
1138 <column name="external_ids">
1139 Key-value pairs for use by external frameworks that integrate with Open
1140 vSwitch, rather than by Open vSwitch itself. System integrators should
1141 either use the Open vSwitch development mailing list to coordinate on
1142 common key-value definitions, or choose key names that are likely to be
1143 unique. No common key-value pairs are currently defined.
1147 <table name="Monitor" title="Connectivity Monitor configuration">
1149 A <ref table="Monitor"/> attaches to an <ref table="Interface"/> to
1150 implement 802.1ag Connectivity Fault Management (CFM). CFM allows a
1151 group of Maintenance Points (MPs) called a Maintenance Association (MA)
1152 to detect connectivity problems with each other. MPs within a MA should
1153 have complete and exclusive interconnectivity. This is verified by
1154 occasionally broadcasting Continuity Check Messages (CCMs) at a
1155 configurable transmission interval. A <ref table="Monitor"/> is
1156 responsible for collecting data about other MPs in its MA and
1160 <group title="Monitor Configuration">
1161 <column name="mpid">
1162 A Maintenance Point ID (MPID) uniquely identifies each endpoint within
1163 a Maintenance Association (see <ref column="ma_name"/>). The MPID is
1164 used to identify this <ref table="Monitor"/> to other endpoints in the
1168 <column name="remote_mps">
1169 A set of <ref table="Maintenance_Points"/> which this
1170 <ref table="Monitor"/> should have connectivity to. If this
1171 <ref table="Monitor"/> does not have connectivity to any MPs in this
1172 set, or has connectivity to any MPs not in this set, a fault is
1176 <column name="ma_name">
1177 A Maintenance Association (MA) name pairs with a Maintenance Domain
1178 (MD) name to uniquely identify a MA. A MA is a group of endpoints who
1179 have complete and exclusive interconnectivity. Defaults to
1180 <code>ovs</code> if unset.
1183 <column name="md_name">
1184 A Maintenance Domain name pairs with a Maintenance Association name to
1185 uniquely identify a MA. Defaults to <code>ovs</code> if unset.
1188 <column name="interval">
1189 The transmission interval of CCMs in milliseconds. Three missed CCMs
1190 indicate a connectivity fault. Defaults to 1000ms.
1194 <group title="Monitor Status">
1195 <column name="unexpected_remote_mpids">
1196 A set of MPIDs representing MPs to which this <ref table="Monitor"/>
1197 has detected connectivity that are not in the
1198 <ref column="remote_mps"/> set. This <ref table="Monitor"/> should not
1199 have connectivity to any MPs not listed in <ref column="remote_mps"/>.
1200 Thus, if this set is non-empty a fault is indicated.
1203 <column name="unexpected_remote_maids">
1204 A set of MAIDs representing foreign Maintenance Associations (MAs)
1205 which this <ref table="Monitor"/> has detected connectivity to. A
1206 <ref table="Monitor"/> should not have connectivity to a Maintenance
1207 Association other than its own. Thus, if this set is non-empty a fault
1211 <column name="fault">
1212 Indicates a Connectivity Fault caused by a configuration error, a down
1213 remote MP, or unexpected connectivity to a remote MAID or remote MP.
1218 <table name="Maintenance_Point" title="Maintenance Point configuration">
1220 A <ref table="Maintenance_Point"/> represents a MP which a
1221 <ref table="Monitor"/> has or should have connectivity to.
1224 <group title="Maintenance_Point Configuration">
1225 <column name="mpid">
1226 A Maintenance Point ID (MPID) uniquely identifies each endpoint within
1227 a Maintenance Association. All MPs within a MA should have a unique
1232 <group title="Maintenance_Point Status">
1233 <column name="fault">
1234 Indicates a connectivity fault.
1239 <table name="Mirror" title="Port mirroring (SPAN/RSPAN).">
1240 <p>A port mirror within a <ref table="Bridge"/>.</p>
1241 <p>A port mirror configures a bridge to send selected frames to special
1242 ``mirrored'' ports, in addition to their normal destinations. Mirroring
1243 traffic may also be referred to as SPAN or RSPAN, depending on the
1244 mechanism used for delivery.</p>
1246 <column name="name">
1247 Arbitrary identifier for the <ref table="Mirror"/>.
1250 <group title="Selecting Packets for Mirroring">
1251 <column name="select_all">
1252 If true, every packet arriving or departing on any port is
1253 selected for mirroring.
1256 <column name="select_dst_port">
1257 Ports on which departing packets are selected for mirroring.
1260 <column name="select_src_port">
1261 Ports on which arriving packets are selected for mirroring.
1264 <column name="select_vlan">
1265 VLANs on which packets are selected for mirroring. An empty set
1266 selects packets on all VLANs.
1270 <group title="Mirroring Destination Configuration">
1271 <column name="output_port">
1272 <p>Output port for selected packets, if nonempty. Mutually exclusive
1273 with <ref column="output_vlan"/>.</p>
1274 <p>Specifying a port for mirror output reserves that port exclusively
1275 for mirroring. No frames other than those selected for mirroring
1276 will be forwarded to the port, and any frames received on the port
1277 will be discarded.</p>
1278 <p>This type of mirroring is sometimes called SPAN.</p>
1281 <column name="output_vlan">
1282 <p>Output VLAN for selected packets, if nonempty. Mutually exclusive
1283 with <ref column="output_port"/>.</p>
1284 <p>The frames will be sent out all ports that trunk
1285 <ref column="output_vlan"/>, as well as any ports with implicit VLAN
1286 <ref column="output_vlan"/>. When a mirrored frame is sent out a
1287 trunk port, the frame's VLAN tag will be set to
1288 <ref column="output_vlan"/>, replacing any existing tag; when it is
1289 sent out an implicit VLAN port, the frame will not be tagged. This
1290 type of mirroring is sometimes called RSPAN.</p>
1291 <p><em>Please note:</em> Mirroring to a VLAN can disrupt a network that
1292 contains unmanaged switches. Consider an unmanaged physical switch
1293 with two ports: port 1, connected to an end host, and port 2,
1294 connected to an Open vSwitch configured to mirror received packets
1295 into VLAN 123 on port 2. Suppose that the end host sends a packet on
1296 port 1 that the physical switch forwards to port 2. The Open vSwitch
1297 forwards this packet to its destination and then reflects it back on
1298 port 2 in VLAN 123. This reflected packet causes the unmanaged
1299 physical switch to replace the MAC learning table entry, which
1300 correctly pointed to port 1, with one that incorrectly points to port
1301 2. Afterward, the physical switch will direct packets destined for
1302 the end host to the Open vSwitch on port 2, instead of to the end
1303 host on port 1, disrupting connectivity. If mirroring to a VLAN is
1304 desired in this scenario, then the physical switch must be replaced
1305 by one that learns Ethernet addresses on a per-VLAN basis. In
1306 addition, learning should be disabled on the VLAN containing mirrored
1307 traffic. If this is not done then intermediate switches will learn
1308 the MAC address of each end host from the mirrored traffic. If
1309 packets being sent to that end host are also mirrored, then they will
1310 be dropped since the switch will attempt to send them out the input
1311 port. Disabling learning for the VLAN will cause the switch to
1312 correctly send the packet out all ports configured for that VLAN. If
1313 Open vSwitch is being used as an intermediate switch, learning can be
1314 disabled by adding the mirrored VLAN to <ref column="flood_vlans"/>
1315 in the appropriate <ref table="Bridge"/> table or tables.</p>
1319 <group title="Other Features">
1320 <column name="external_ids">
1321 Key-value pairs for use by external frameworks that integrate with Open
1322 vSwitch, rather than by Open vSwitch itself. System integrators should
1323 either use the Open vSwitch development mailing list to coordinate on
1324 common key-value definitions, or choose key names that are likely to be
1325 unique. No common key-value pairs are currently defined.
1330 <table name="Controller" title="OpenFlow controller configuration.">
1331 <p>An OpenFlow controller.</p>
1334 Open vSwitch supports two kinds of OpenFlow controllers:
1338 <dt>Primary controllers</dt>
1341 This is the kind of controller envisioned by the OpenFlow 1.0
1342 specification. Usually, a primary controller implements a network
1343 policy by taking charge of the switch's flow table.
1347 Open vSwitch initiates and maintains persistent connections to
1348 primary controllers, retrying the connection each time it fails or
1349 drops. The <ref table="Bridge" column="fail_mode"/> column in the
1350 <ref table="Bridge"/> table applies to primary controllers.
1354 Open vSwitch permits a bridge to have any number of primary
1355 controllers. When multiple controllers are configured, Open
1356 vSwitch connects to all of them simultaneously. Because
1357 OpenFlow 1.0 does not specify how multiple controllers
1358 coordinate in interacting with a single switch, more than
1359 one primary controller should be specified only if the
1360 controllers are themselves designed to coordinate with each
1361 other. (The Nicira-defined <code>NXT_ROLE</code> OpenFlow
1362 vendor extension may be useful for this.)
1365 <dt>Service controllers</dt>
1368 These kinds of OpenFlow controller connections are intended for
1369 occasional support and maintenance use, e.g. with
1370 <code>ovs-ofctl</code>. Usually a service controller connects only
1371 briefly to inspect or modify some of a switch's state.
1375 Open vSwitch listens for incoming connections from service
1376 controllers. The service controllers initiate and, if necessary,
1377 maintain the connections from their end. The <ref table="Bridge"
1378 column="fail_mode"/> column in the <ref table="Bridge"/> table does
1379 not apply to service controllers.
1383 Open vSwitch supports configuring any number of service controllers.
1389 The <ref column="target"/> determines the type of controller.
1392 <group title="Core Features">
1393 <column name="target">
1394 <p>Connection method for controller.</p>
1396 The following connection methods are currently supported for primary
1400 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1402 <p>The specified SSL <var>port</var> (default: 6633) on the host at
1403 the given <var>ip</var>, which must be expressed as an IP address
1404 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1405 column in the <ref table="Open_vSwitch"/> table must point to a
1406 valid SSL configuration when this form is used.</p>
1407 <p>SSL support is an optional feature that is not always built as
1408 part of Open vSwitch.</p>
1410 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1411 <dd>The specified TCP <var>port</var> (default: 6633) on the host at
1412 the given <var>ip</var>, which must be expressed as an IP address
1413 (not a DNS name).</dd>
1414 <dt><code>discover</code></dt>
1416 <p>Enables controller discovery.</p>
1417 <p>In controller discovery mode, Open vSwitch broadcasts a DHCP
1418 request with vendor class identifier <code>OpenFlow</code> across
1419 all of the bridge's network devices. It will accept any valid
1420 DHCP reply that has the same vendor class identifier and includes
1421 a vendor-specific option with code 1 whose contents are a string
1422 specifying the location of the controller in the same format as
1423 <ref column="target"/>.</p>
1424 <p>The DHCP reply may also, optionally, include a vendor-specific
1425 option with code 2 whose contents are a string specifying the URI
1426 to the base of the OpenFlow PKI
1427 (e.g. <code>http://192.168.0.1/openflow/pki</code>). This URI is
1428 used only for bootstrapping the OpenFlow PKI at initial switch
1429 setup; <code>ovs-vswitchd</code> does not use it at all.</p>
1433 The following connection methods are currently supported for service
1437 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1440 Listens for SSL connections on the specified TCP <var>port</var>
1441 (default: 6633). If <var>ip</var>, which must be expressed as an
1442 IP address (not a DNS name), is specified, then connections are
1443 restricted to the specified local IP address.
1446 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1447 table="Open_vSwitch"/> table must point to a valid SSL
1448 configuration when this form is used.
1450 <p>SSL support is an optional feature that is not always built as
1451 part of Open vSwitch.</p>
1453 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1455 Listens for connections on the specified TCP <var>port</var>
1456 (default: 6633). If <var>ip</var>, which must be expressed as an
1457 IP address (not a DNS name), is specified, then connections are
1458 restricted to the specified local IP address.
1461 <p>When multiple controllers are configured for a single bridge, the
1462 <ref column="target"/> values must be unique. Duplicate
1463 <ref column="target"/> values yield unspecified results.</p>
1466 <column name="connection_mode">
1467 <p>If it is specified, this setting must be one of the following
1468 strings that describes how Open vSwitch contacts this OpenFlow
1469 controller over the network:</p>
1472 <dt><code>in-band</code></dt>
1473 <dd>In this mode, this controller's OpenFlow traffic travels over the
1474 bridge associated with the controller. With this setting, Open
1475 vSwitch allows traffic to and from the controller regardless of the
1476 contents of the OpenFlow flow table. (Otherwise, Open vSwitch
1477 would never be able to connect to the controller, because it did
1478 not have a flow to enable it.) This is the most common connection
1479 mode because it is not necessary to maintain two independent
1481 <dt><code>out-of-band</code></dt>
1482 <dd>In this mode, OpenFlow traffic uses a control network separate
1483 from the bridge associated with this controller, that is, the
1484 bridge does not use any of its own network devices to communicate
1485 with the controller. The control network must be configured
1486 separately, before or after <code>ovs-vswitchd</code> is started.
1490 <p>If not specified, the default is implementation-specific. If
1491 <ref column="target"/> is <code>discover</code>, the connection mode
1492 is always treated as <code>in-band</code> regardless of the actual
1497 <group title="Controller Failure Detection and Handling">
1498 <column name="max_backoff">
1499 Maximum number of milliseconds to wait between connection attempts.
1500 Default is implementation-specific.
1503 <column name="inactivity_probe">
1504 Maximum number of milliseconds of idle time on connection to
1505 controller before sending an inactivity probe message. If Open
1506 vSwitch does not communicate with the controller for the specified
1507 number of seconds, it will send a probe. If a response is not
1508 received for the same additional amount of time, Open vSwitch
1509 assumes the connection has been broken and attempts to reconnect.
1510 Default is implementation-specific.
1514 <group title="OpenFlow Rate Limiting">
1515 <column name="controller_rate_limit">
1516 <p>The maximum rate at which packets in unknown flows will be
1517 forwarded to the OpenFlow controller, in packets per second. This
1518 feature prevents a single bridge from overwhelming the controller.
1519 If not specified, the default is implementation-specific.</p>
1520 <p>In addition, when a high rate triggers rate-limiting, Open
1521 vSwitch queues controller packets for each port and transmits
1522 them to the controller at the configured rate. The number of
1523 queued packets is limited by
1524 the <ref column="controller_burst_limit"/> value. The packet
1525 queue is shared fairly among the ports on a bridge.</p><p>Open
1526 vSwitch maintains two such packet rate-limiters per bridge.
1527 One of these applies to packets sent up to the controller
1528 because they do not correspond to any flow. The other applies
1529 to packets sent up to the controller by request through flow
1530 actions. When both rate-limiters are filled with packets, the
1531 actual rate that packets are sent to the controller is up to
1532 twice the specified rate.</p>
1535 <column name="controller_burst_limit">
1536 In conjunction with <ref column="controller_rate_limit"/>,
1537 the maximum number of unused packet credits that the bridge will
1538 allow to accumulate, in packets. If not specified, the default
1539 is implementation-specific.
1543 <group title="Additional Discovery Configuration">
1544 <p>These values are considered only when <ref column="target"/>
1545 is <code>discover</code>.</p>
1547 <column name="discover_accept_regex">
1549 extended regular expression against which the discovered controller
1550 location is validated. The regular expression is implicitly
1551 anchored at the beginning of the controller location string, as
1552 if it begins with <code>^</code>. If not specified, the default
1553 is implementation-specific.
1556 <column name="discover_update_resolv_conf">
1557 Whether to update <code>/etc/resolv.conf</code> when the
1558 controller is discovered. If not specified, the default
1559 is implementation-specific. Open vSwitch will only modify
1560 <code>/etc/resolv.conf</code> if the DHCP response that it receives
1561 specifies one or more DNS servers.
1565 <group title="Additional In-Band Configuration">
1566 <p>These values are considered only in in-band control mode (see
1567 <ref column="connection_mode"/>) and only when <ref column="target"/>
1568 is not <code>discover</code>. (For controller discovery, the network
1569 configuration obtained via DHCP is used instead.)</p>
1571 <p>When multiple controllers are configured on a single bridge, there
1572 should be only one set of unique values in these columns. If different
1573 values are set for these columns in different controllers, the effect
1576 <column name="local_ip">
1577 The IP address to configure on the local port,
1578 e.g. <code>192.168.0.123</code>. If this value is unset, then
1579 <ref column="local_netmask"/> and <ref column="local_gateway"/> are
1583 <column name="local_netmask">
1584 The IP netmask to configure on the local port,
1585 e.g. <code>255.255.255.0</code>. If <ref column="local_ip"/> is set
1586 but this value is unset, then the default is chosen based on whether
1587 the IP address is class A, B, or C.
1590 <column name="local_gateway">
1591 The IP address of the gateway to configure on the local port, as a
1592 string, e.g. <code>192.168.0.1</code>. Leave this column unset if
1593 this network has no gateway.
1597 <group title="Other Features">
1598 <column name="external_ids">
1599 Key-value pairs for use by external frameworks that integrate with Open
1600 vSwitch, rather than by Open vSwitch itself. System integrators should
1601 either use the Open vSwitch development mailing list to coordinate on
1602 common key-value definitions, or choose key names that are likely to be
1603 unique. No common key-value pairs are currently defined.
1608 <table name="Manager" title="OVSDB management connection.">
1610 Configuration for a database connection to an Open vSwitch database
1615 This table primarily configures the Open vSwitch database
1616 (<code>ovsdb-server</code>), not the Open vSwitch switch
1617 (<code>ovs-vswitchd</code>). The switch does read the table to determine
1618 what connections should be treated as in-band.
1622 The Open vSwitch database server can initiate and maintain active
1623 connections to remote clients. It can also listen for database
1627 <group title="Core Features">
1628 <column name="target">
1629 <p>Connection method for managers.</p>
1631 The following connection methods are currently supported:
1634 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1637 The specified SSL <var>port</var> (default: 6632) on the host at
1638 the given <var>ip</var>, which must be expressed as an IP address
1639 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
1640 column in the <ref table="Open_vSwitch"/> table must point to a
1641 valid SSL configuration when this form is used.
1644 SSL support is an optional feature that is not always built as
1645 part of Open vSwitch.
1649 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
1651 The specified TCP <var>port</var> (default: 6632) on the host at
1652 the given <var>ip</var>, which must be expressed as an IP address
1655 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1658 Listens for SSL connections on the specified TCP <var>port</var>
1659 (default: 6632). If <var>ip</var>, which must be expressed as an
1660 IP address (not a DNS name), is specified, then connections are
1661 restricted to the specified local IP address.
1664 The <ref table="Open_vSwitch" column="ssl"/> column in the <ref
1665 table="Open_vSwitch"/> table must point to a valid SSL
1666 configuration when this form is used.
1669 SSL support is an optional feature that is not always built as
1670 part of Open vSwitch.
1673 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
1675 Listens for connections on the specified TCP <var>port</var>
1676 (default: 6632). If <var>ip</var>, which must be expressed as an
1677 IP address (not a DNS name), is specified, then connections are
1678 restricted to the specified local IP address.
1681 <p>When multiple managers are configured, the <ref column="target"/>
1682 values must be unique. Duplicate <ref column="target"/> values yield
1683 unspecified results.</p>
1686 <column name="connection_mode">
1688 If it is specified, this setting must be one of the following strings
1689 that describes how Open vSwitch contacts this OVSDB client over the
1694 <dt><code>in-band</code></dt>
1696 In this mode, this connection's traffic travels over a bridge
1697 managed by Open vSwitch. With this setting, Open vSwitch allows
1698 traffic to and from the client regardless of the contents of the
1699 OpenFlow flow table. (Otherwise, Open vSwitch would never be able
1700 to connect to the client, because it did not have a flow to enable
1701 it.) This is the most common connection mode because it is not
1702 necessary to maintain two independent networks.
1704 <dt><code>out-of-band</code></dt>
1706 In this mode, the client's traffic uses a control network separate
1707 from that managed by Open vSwitch, that is, Open vSwitch does not
1708 use any of its own network devices to communicate with the client.
1709 The control network must be configured separately, before or after
1710 <code>ovs-vswitchd</code> is started.
1715 If not specified, the default is implementation-specific.
1720 <group title="Client Failure Detection and Handling">
1721 <column name="max_backoff">
1722 Maximum number of milliseconds to wait between connection attempts.
1723 Default is implementation-specific.
1726 <column name="inactivity_probe">
1727 Maximum number of milliseconds of idle time on connection to the client
1728 before sending an inactivity probe message. If Open vSwitch does not
1729 communicate with the client for the specified number of seconds, it
1730 will send a probe. If a response is not received for the same
1731 additional amount of time, Open vSwitch assumes the connection has been
1732 broken and attempts to reconnect. Default is implementation-specific.
1736 <group title="Other Features">
1737 <column name="external_ids">
1738 Key-value pairs for use by external frameworks that integrate with Open
1739 vSwitch, rather than by Open vSwitch itself. System integrators should
1740 either use the Open vSwitch development mailing list to coordinate on
1741 common key-value definitions, or choose key names that are likely to be
1742 unique. No common key-value pairs are currently defined.
1747 <table name="NetFlow">
1748 A NetFlow target. NetFlow is a protocol that exports a number of
1749 details about terminating IP flows, such as the principals involved
1752 <column name="targets">
1753 NetFlow targets in the form
1754 <code><var>ip</var>:<var>port</var></code>. The <var>ip</var>
1755 must be specified numerically, not as a DNS name.
1758 <column name="engine_id">
1759 Engine ID to use in NetFlow messages. Defaults to datapath index
1763 <column name="engine_type">
1764 Engine type to use in NetFlow messages. Defaults to datapath
1765 index if not specified.
1768 <column name="active_timeout">
1769 The interval at which NetFlow records are sent for flows that are
1770 still active, in seconds. A value of <code>0</code> requests the
1771 default timeout (currently 600 seconds); a value of <code>-1</code>
1772 disables active timeouts.
1775 <column name="add_id_to_interface">
1776 <p>If this column's value is <code>false</code>, the ingress and egress
1777 interface fields of NetFlow flow records are derived from OpenFlow port
1778 numbers. When it is <code>true</code>, the 7 most significant bits of
1779 these fields will be replaced by the least significant 7 bits of the
1780 engine id. This is useful because many NetFlow collectors do not
1781 expect multiple switches to be sending messages from the same host, so
1782 they do not store the engine information which could be used to
1783 disambiguate the traffic.</p>
1784 <p>When this option is enabled, a maximum of 508 ports are supported.</p>
1787 <column name="external_ids">
1788 Key-value pairs for use by external frameworks that integrate with Open
1789 vSwitch, rather than by Open vSwitch itself. System integrators should
1790 either use the Open vSwitch development mailing list to coordinate on
1791 common key-value definitions, or choose key names that are likely to be
1792 unique. No common key-value pairs are currently defined.
1797 SSL configuration for an Open_vSwitch.
1799 <column name="private_key">
1800 Name of a PEM file containing the private key used as the switch's
1801 identity for SSL connections to the controller.
1804 <column name="certificate">
1805 Name of a PEM file containing a certificate, signed by the
1806 certificate authority (CA) used by the controller and manager,
1807 that certifies the switch's private key, identifying a trustworthy
1811 <column name="ca_cert">
1812 Name of a PEM file containing the CA certificate used to verify
1813 that the switch is connected to a trustworthy controller.
1816 <column name="bootstrap_ca_cert">
1817 If set to <code>true</code>, then Open vSwitch will attempt to
1818 obtain the CA certificate from the controller on its first SSL
1819 connection and save it to the named PEM file. If it is successful,
1820 it will immediately drop the connection and reconnect, and from then
1821 on all SSL connections must be authenticated by a certificate signed
1822 by the CA certificate thus obtained. <em>This option exposes the
1823 SSL connection to a man-in-the-middle attack obtaining the initial
1824 CA certificate.</em> It may still be useful for bootstrapping.
1827 <column name="external_ids">
1828 Key-value pairs for use by external frameworks that integrate with Open
1829 vSwitch, rather than by Open vSwitch itself. System integrators should
1830 either use the Open vSwitch development mailing list to coordinate on
1831 common key-value definitions, or choose key names that are likely to be
1832 unique. No common key-value pairs are currently defined.
1836 <table name="sFlow">
1837 <p>An sFlow(R) target. sFlow is a protocol for remote monitoring
1840 <column name="agent">
1841 Name of the network device whose IP address should be reported as the
1842 ``agent address'' to collectors. If not specified, the IP address
1843 defaults to the <ref table="Controller" column="local_ip"/> in the
1844 collector's <ref table="Controller"/>. If an agent IP address cannot be
1845 determined either way, sFlow is disabled.
1848 <column name="header">
1849 Number of bytes of a sampled packet to send to the collector.
1850 If not specified, the default is 128 bytes.
1853 <column name="polling">
1854 Polling rate in seconds to send port statistics to the collector.
1855 If not specified, defaults to 30 seconds.
1858 <column name="sampling">
1859 Rate at which packets should be sampled and sent to the collector.
1860 If not specified, defaults to 400, which means one out of 400
1861 packets, on average, will be sent to the collector.
1864 <column name="targets">
1865 sFlow targets in the form
1866 <code><var>ip</var>:<var>port</var></code>.
1869 <column name="external_ids">
1870 Key-value pairs for use by external frameworks that integrate with Open
1871 vSwitch, rather than by Open vSwitch itself. System integrators should
1872 either use the Open vSwitch development mailing list to coordinate on
1873 common key-value definitions, or choose key names that are likely to be
1874 unique. No common key-value pairs are currently defined.
1878 <table name="Capability">
1879 <p>Records in this table describe functionality supported by the hardware
1880 and software platform on which this Open vSwitch is based. Clients
1881 should not modify this table.</p>
1883 <p>A record in this table is meaningful only if it is referenced by the
1884 <ref table="Open_vSwitch" column="capabilities"/> column in the
1885 <ref table="Open_vSwitch"/> table. The key used to reference it, called
1886 the record's ``category,'' determines the meanings of the
1887 <ref column="details"/> column. The following general forms of
1888 categories are currently defined:</p>
1891 <dt><code>qos-<var>type</var></code></dt>
1892 <dd><var>type</var> is supported as the value for
1893 <ref column="type" table="QoS"/> in the <ref table="QoS"/> table.
1897 <column name="details">
1898 <p>Key-value pairs that describe capabilities. The meaning of the pairs
1899 depends on the category key that the <ref table="Open_vSwitch"
1900 column="capabilities"/> column in the <ref table="Open_vSwitch"/> table
1901 uses to reference this record, as described above.</p>
1903 <p>The presence of a record for category <code>qos-<var>type</var></code>
1904 indicates that the switch supports <var>type</var> as the value of
1905 the <ref table="QoS" column="type"/> column in the <ref table="QoS"/>
1906 table. The following key-value pairs are defined to further describe
1907 QoS capabilities:</p>
1910 <dt><code>n-queues</code></dt>
1911 <dd>Number of supported queues, as a positive integer. Keys in the
1912 <ref table="QoS" column="queues"/> column for <ref table="QoS"/>
1913 records whose <ref table="QoS" column="type"/> value
1914 equals <var>type</var> must range between 0 and this value minus one,