1 <database title="Open vSwitch Configuration Database">
2 <p>A database with this schema holds the configuration for one Open
3 vSwitch daemon. The root of the configuration for the daemon is
4 the <ref table="Open_vSwitch"/> table, which must have exactly one
5 record. Records in other tables are significant only when they
6 can be reached directly or indirectly from the
7 <ref table="Open_vSwitch"/> table.</p>
9 <table name="Open_vSwitch" title="Open vSwitch configuration.">
10 Configuration for an Open vSwitch daemon. There must be exactly one record
11 in the <ref table="Open_vSwitch"/> table.
13 <group title="Configuration">
14 <column name="bridges">
15 Set of bridges managed by the daemon.
18 <column name="controller">
19 Default <ref table="Controller"/> used by bridges. May be
20 overridden on a per-bridge basis by the <ref table="Bridge"
21 column="controller"/> column in <ref table="Bridge"/>.
24 <column name="managers">
25 Remote database clients to which the Open vSwitch's database server
26 should connect or to which it should listen.
30 SSL used globally by the daemon.
34 <group title="Status">
35 <column name="next_cfg">
36 Sequence number for client to increment. When a client modifies
37 any part of the database configuration and wishes to wait for
38 Open vSwitch to finish applying the changes, it may increment
42 <column name="cur_cfg">
43 Sequence number that Open vSwitch sets to the current value of
44 <ref column="next_cfg"/> after it finishes applying a set of
45 configuration changes.
52 Configuration for a bridge within an
53 <ref table="Open_vSwitch"/>.
56 A <ref table="Bridge"/> record represents an Ethernet switch with one or
57 more ``ports,'' which are the <ref table="Port"/> records pointed to by
58 the <ref table="Bridge"/>'s <ref column="ports"/> column.
61 <group title="Core Features">
63 Bridge identifier. Should be alphanumeric and no more than about 8
64 bytes long. Must be unique among the names of ports, interfaces, and
69 Ports included in the bridge.
72 <column name="mirrors">
73 Port mirroring configuration.
76 <column name="netflow">
77 NetFlow configuration.
84 <column name="flood_vlans">
85 VLAN IDs of VLANs on which MAC address learning should be disabled, so
86 that packets are flooded instead of being sent to specific ports that
87 are believed to contain packets' destination MACs. This should
88 ordinarily be used to disable MAC learning on VLANs used for mirroring
89 (RSPAN VLANs). It may also be useful for debugging.
93 <group title="OpenFlow Configuration">
94 <column name="controller">
95 OpenFlow controller. If unset, defaults to that specified by
96 <ref column="controller" table="Open_vSwitch"/> in the
97 <ref table="Open_vSwitch"/> table. If the default is also unset, then
98 no OpenFlow controller will be used.
101 <column name="datapath_id">
102 Reports the OpenFlow datapath ID in use. Exactly 16 hex digits.
106 <group title="Other Features">
107 <column name="datapath_type">
108 Name of datapath provider. The kernel datapath has
109 type <code>system</code>. The userspace datapath has
110 type <code>netdev</code>.
113 <column name="external_ids">
114 Key-value pairs that identify this bridge's role in external systems.
115 The currently defined key-value pairs are:
117 <dt><code>xs-network-uuids</code></dt>
118 <dd>Space-delimited set of the Citrix XenServer network UUIDs with
119 which this bridge is associated.</dd>
120 <dt><code>xs-network-names</code></dt>
121 <dd>Semicolon-delimited set of Citrix XenServer network names with
122 which this bridge is associated.</dd>
126 <column name="other_config">
127 Key-value pairs for configuring rarely used bridge
128 features. The currently defined key-value pairs are:
130 <dt><code>datapath-id</code></dt>
132 digits to set the OpenFlow datapath ID to a specific
134 <dt><code>hwaddr</code></dt>
135 <dd>An Ethernet address in the form
136 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>
137 to set the hardware address of the local port and influence the
144 <table name="Port" table="Port or bond configuration.">
145 <p>A port within a <ref table="Bridge"/>.</p>
146 <p>Most commonly, a port has exactly one ``interface,'' pointed to by its
147 <ref column="interfaces"/> column. Such a port logically
148 corresponds to a port on a physical Ethernet switch. A port
149 with more than one interface is a ``bonded port'' (see
150 <ref group="Bonding Configuration"/>).</p>
151 <p>Some properties that one might think as belonging to a port are actually
152 part of the port's <ref table="Interface"/> members.</p>
155 Port name. Should be alphanumeric and no more than about 8
156 bytes long. May be the same as the interface name, for
157 non-bonded ports. Must otherwise be unique among the names of
158 ports, interfaces, and bridges on a host.
161 <column name="interfaces">
162 The port's interfaces. If there is more than one, this is a
166 <group title="VLAN Configuration">
167 <p>A bridge port must be configured for VLANs in one of two
168 mutually exclusive ways:
170 <li>A ``trunk port'' has an empty value for
171 <ref column="tag"/> and a possibly non-empty
172 <ref column="trunks"/> value.</li>
173 <li>An ``implicitly tagged VLAN port'' or ``access port''
174 has an nonempty value for <ref column="tag"/> and an empty
175 <ref column="trunks"/> value.</li>
177 If <ref column="trunks"/> and <ref column="tag"/> are both
178 nonempty, the configuration is ill-formed.
182 <p>If nonempty, this port's implicitly tagged VLAN. Frames
183 arriving on trunk ports will be forwarded to this port only
184 if they are tagged with the given VLAN. Frames arriving on
185 other VLAN ports will be forwarded to this port only if they
186 have the same <ref column="tag"/> value. Frames forwarded
187 to this port will not have an 802.1Q header.</p>
188 <p>When a frame with a 802.1Q header that indicates a nonzero VLAN is
189 received on an implicit VLAN port, it is discarded.</p>
190 <p>Must be empty if this is a trunk port.</p>
193 <column name="trunks">
194 <p>The 802.1Q VLAN(s) that this port trunks. If the column is
195 empty, then the port trunks all VLANs as well as packets that
196 have no VLAN header. Otherwise, only frames that have an
197 802.1Q header with one of the specified VLANs are accepted.
198 If <code>0</code> is included, then frames without an 802.1Q
199 header are also accepted.</p>
200 <p>Must be empty unless this is a trunk port.</p>
204 <group title="Bonding Configuration">
205 <p>A port that has more than one interface is a ``bonded port.''
206 Bonding allows for load balancing and fail-over. Open vSwitch
207 supports ``source load balancing'' (SLB) bonding, which
208 assigns flows to slaves based on source MAC address, with
209 periodic rebalancing as traffic patterns change. This form of
210 bonding does not require 802.3ad or other special support from
211 the upstream switch to which the slave devices are
214 <p>These columns apply only to bonded ports. Their values are
215 otherwise ignored.</p>
217 <column name="bond_updelay">
218 <p>For a bonded port, the number of milliseconds for which carrier must
219 stay up on an interface before the interface is considered to be up.
220 Specify <code>0</code> to enable the interface immediately.</p>
221 <p>This setting is honored only when at least one bonded interface is
222 already enabled. When no interfaces are enabled, then the first bond
223 interface to come up is enabled immediately.</p>
226 <column name="bond_downdelay">
227 For a bonded port, the number of milliseconds for which carrier must
228 stay down on an interface before the interface is considered to be
229 down. Specify <code>0</code> to disable the interface immediately.
232 <column name="bond_fake_iface">
233 For a bonded port, whether to create a fake internal interface with the
234 name of the port. Use only for compatibility with legacy software that
239 <group title="Other Features">
241 The MAC address to use for this port for the purpose of choosing the
242 bridge's MAC address. This column does not necessarily reflect the
243 port's actual MAC address, nor will setting it change the port's actual
247 <column name="fake_bridge">
248 Does this port represent a sub-bridge for its tagged VLAN within the
249 Bridge? See ovs-vsctl(8) for more information.
252 <column name="external_ids">
253 Key-value pairs that identify this port's role in external systems. No
254 key-value pairs native to <ref table="Port"/> are currently defined.
255 For fake bridges (see the <ref column="fake_bridge"/> column), external
256 IDs for the fake bridge are defined here by prefixing a
257 <ref table="Bridge"/> <ref table="Bridge" column="external_ids"/> key
258 with <code>fake-bridge-</code>,
259 e.g. <code>fake-bridge-xs-network-uuids</code>.
262 <column name="other_config">
263 Key-value pairs for configuring rarely used port features. The
264 currently defined key-value pairs are:
266 <dt><code>hwaddr</code></dt>
267 <dd>An Ethernet address in the form
268 <code><var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var></code>.</dd>
274 <table name="Interface" title="One physical network device in a Port.">
275 An interface within a <ref table="Port"/>.
277 <group title="Core Features">
279 Interface name. Should be alphanumeric and no more than about 8 bytes
280 long. May be the same as the port name, for non-bonded ports. Must
281 otherwise be unique among the names of ports, interfaces, and bridges
286 <p>Ethernet address to set for this interface. If unset then the
287 default MAC address is used:</p>
289 <li>For the local interface, the default is the lowest-numbered MAC
290 address among the other bridge ports, either the value of the
291 <ref table="Port" column="mac"/> in its <ref table="Port"/> record,
292 if set, or its actual MAC (for bonded ports, the MAC of its slave
293 whose name is first in alphabetical order). Internal ports and
294 bridge ports that are used as port mirroring destinations (see the
295 <ref table="Mirror"/> table) are ignored.</li>
296 <li>For other internal interfaces, the default MAC is randomly
298 <li>External interfaces typically have a MAC address associated with
301 <p>Some interfaces may not have a software-controllable MAC
305 <column name="ofport">
306 <p>OpenFlow port number for this interface. Unlike most columns, this
307 column's value should be set only by Open vSwitch itself. Other
308 clients should set this column to an empty set (the default) when
309 creating an <ref table="Interface"/>.</p>
310 <p>Open vSwitch populates this column when the port number becomes
311 known. If the interface is successfully added,
312 <ref column="ofport"/> will be set to a number between 1 and 65535
313 (generally either in the range 1 to 65280, exclusive, or 65534, the
314 port number for the OpenFlow ``local port''). If the interface
315 cannot be added then Open vSwitch sets this column
320 <group title="System-Specific Details">
322 The interface type, one of:
324 <dt><code>system</code></dt>
325 <dd>An ordinary network device, e.g. <code>eth0</code> on Linux.
326 Sometimes referred to as ``external interfaces'' since they are
327 generally connected to hardware external to that on which the Open
328 vSwitch is running. The empty string is a synonym for
329 <code>system</code>.</dd>
330 <dt><code>internal</code></dt>
331 <dd>A simulated network device that sends and receives traffic. An
332 internal interface whose <ref column="name"/> is the same as its
333 bridge's <ref table="Open_vSwitch" column="name"/> is called the
334 ``local interface.'' It does not make sense to bond an internal
335 interface, so the terms ``port'' and ``interface'' are often used
336 imprecisely for internal interfaces.</dd>
337 <dt><code>tap</code></dt>
338 <dd>A TUN/TAP device managed by Open vSwitch.</dd>
339 <dt><code>gre</code></dt>
340 <dd>A GRE tunnel device managed by Open vSwitch.</dd>
344 <column name="options">
345 Configuration options whose interpretation varies based on
346 <ref column="type"/>.
350 <group title="Ingress Policing">
351 <column name="ingress_policing_burst">
352 <p>Maximum burst size for data received on this interface, in kb. The
353 default burst size if set to <code>0</code> is 1000 kb. This value
354 has no effect if <ref column="ingress_policing_rate"/>
355 is <code>0</code>.</p>
356 <p>The burst size should be at least the size of the interface's
360 <column name="ingress_policing_rate">
361 <p>Maximum rate for data received on this interface, in kbps. Data
362 received faster than this rate is dropped. Set to <code>0</code> to
363 disable policing.</p>
364 <p>The meaning of ``ingress'' is from Open vSwitch's perspective. If
365 configured on a physical interface, then it limits the rate at which
366 traffic is allowed into the system from the outside. If configured
367 on a virtual interface that is connected to a virtual machine, then
368 it limits the rate at which the guest is able to transmit.</p>
372 <group title="Other Features">
373 <column name="external_ids">
374 Key-value pairs that identify this interface's role in external
375 systems. The currently defined key-value pairs are:
377 <dt><code>xs-vif-uuid</code></dt>
378 <dd>UUID of the Citrix XenServer VIF associated with this
380 <dt><code>xs-network-uuid</code></dt>
381 <dd>UUID of the Citrix XenServer network to which this interface is
383 <dt><code>xs-vif-vm-uuid</code></dt>
384 <dd>UUID of the Citrix XenServer VM to which this interface
386 <dt><code>xs-vif-mac</code></dt>
387 <dd>The value of the "MAC" field in the Citrix XenServer VIF record
388 for this interface.</dd>
394 <table name="Mirror" title="Port mirroring (SPAN/RSPAN).">
395 <p>A port mirror within a <ref table="Bridge"/>.</p>
396 <p>A port mirror configures a bridge to send selected frames to special
397 ``mirrored'' ports, in addition to their normal destinations. Mirroring
398 traffic may also be referred to as SPAN or RSPAN, depending on the
399 mechanism used for delivery.</p>
402 Arbitrary identifier for the <ref table="Mirror"/>.
405 <group title="Selecting Packets for Mirroring">
406 <column name="select_dst_port">
407 Ports on which departing packets are selected for mirroring.
410 <column name="select_src_port">
411 Ports on which arriving packets are selected for mirroring. If this
412 column and <ref column="select_dst_port"/> are both empty, then all
413 packets on all ports are selected for mirroring.
416 <column name="select_vlan">
417 VLANs on which packets are selected for mirroring. An empty set
418 selects packets on all VLANs.
422 <group title="Mirroring Destination Configuration">
423 <column name="output_port">
424 <p>Output port for selected packets, if nonempty. Mutually exclusive
425 with <ref column="output_vlan"/>.</p>
426 <p>Specifying a port for mirror output reserves that port exclusively
427 for mirroring. No frames other than those selected for mirroring
428 will be forwarded to the port, and any frames received on the port
429 will be discarded.</p>
430 <p>This type of mirroring is sometimes called SPAN.</p>
433 <column name="output_vlan">
434 <p>Output VLAN for selected packets, if nonempty. Mutually exclusive
435 with <ref column="output_port"/>.</p>
436 <p>The frames will be sent out all ports that trunk
437 <ref column="output_vlan"/>, as well as any ports with implicit VLAN
438 <ref column="output_vlan"/>. When a mirrored frame is sent out a
439 trunk port, the frame's VLAN tag will be set to
440 <ref column="output_vlan"/>, replacing any existing tag; when it is
441 sent out an implicit VLAN port, the frame will not be tagged. This
442 type of mirroring is sometimes called RSPAN.</p>
443 <p><em>Please note:</em> Mirroring to a VLAN can disrupt a network that
444 contains unmanaged switches. Consider an unmanaged physical switch
445 with two ports: port 1, connected to an end host, and port 2,
446 connected to an Open vSwitch configured to mirror received packets
447 into VLAN 123 on port 2. Suppose that the end host sends a packet on
448 port 1 that the physical switch forwards to port 2. The Open vSwitch
449 forwards this packet to its destination and then reflects it back on
450 port 2 in VLAN 123. This reflected packet causes the unmanaged
451 physical switch to replace the MAC learning table entry, which
452 correctly pointed to port 1, with one that incorrectly points to port
453 2. Afterward, the physical switch will direct packets destined for
454 the end host to the Open vSwitch on port 2, instead of to the end
455 host on port 1, disrupting connectivity. If mirroring to a VLAN is
456 desired in this scenario, then the physical switch must be replaced
457 by one that learns Ethernet addresses on a per-VLAN basis. In
458 addition, learning should be disabled on the VLAN containing mirrored
459 traffic. If this is not done then intermediate switches will learn
460 the MAC address of each end host from the mirrored traffic. If
461 packets being sent to that end host are also mirrored, then they will
462 be dropped since the switch will attempt to send them out the input
463 port. Disabling learning for the VLAN will cause the switch to
464 correctly send the packet out all ports configured for that VLAN. If
465 Open vSwitch is being used as an intermediate switch, learning can be
466 disabled by adding the mirrored VLAN to <ref column="flood_vlans"/>
467 in the appropriate <ref table="Bridge"/> table or tables.</p>
472 <table name="Controller" title="OpenFlow controller configuration.">
473 An OpenFlow controller.
475 <group title="Core Features">
476 <column name="target">
477 Connection method for controller.
478 The following connection methods are currently
481 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
483 <p>The specified SSL <var>port</var> (default: 6633) on the host at
484 the given <var>ip</var>, which must be expressed as an IP address
485 (not a DNS name). The <ref table="Open_vSwitch" column="ssl"/>
486 column in the <ref table="Open_vSwitch"/> must point to a valid
487 SSL configuration when this form is used.</p>
488 <p>SSL support is an optional feature that is not always built as
489 part of Open vSwitch.</p>
491 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
492 <dd>The specified TCP <var>port</var> (default: 6633) on the host at
493 the given <var>ip</var>, which must be expressed as an IP address
494 (not a DNS name).</dd>
495 <dt><code>discover</code></dt>
496 <dd>Enables controller discovery.</dd>
497 <dt><code>none</code></dt>
498 <dd>Disables the controller.</dd>
502 <column name="connection_mode">
503 Either <code>in-band</code> or <code>out-of-band</code>. If not
504 specified, the default is implementation-specific.
508 <group title="Controller Failure Detection and Handling">
509 <column name="max_backoff">
510 Maximum number of milliseconds to wait between connection attempts.
511 Default is implementation-specific.
514 <column name="inactivity_probe">
515 Maximum number of milliseconds of idle time on connection to
516 controller before sending an inactivity probe message. If Open
517 vSwitch does not communicate with the controller for the specified
518 number of seconds, it will send a probe. If a response is not
519 received for the same additional amount of time, Open vSwitch
520 assumes the connection has been broken and attempts to reconnect.
521 Default is implementation-specific.
524 <column name="fail_mode">
525 <p>When a controller is configured, it is, ordinarily, responsible
526 for setting up all flows on the switch. Thus, if the connection to
527 the controller fails, no new network connections can be set up.
528 If the connection to the controller stays down long enough,
529 no packets can pass through the switch at all. This setting
530 determines the switch's response to such a situation. It may be set
531 to one of the following:
533 <dt><code>standalone</code></dt>
534 <dd>If no message is received from the controller for three
535 times the inactivity probe interval
536 (see <ref column="inactivity_probe"/>), then Open vSwitch
537 will take over responsibility for setting up flows. In
538 this mode, Open vSwitch causes the datapath to act like an
539 ordinary MAC-learning switch. Open vSwitch will continue
540 to retry connecting to the controller in the background
541 and, when the connection succeeds, it will discontinue its
542 standalone behavior.</dd>
543 <dt><code>secure</code></dt>
544 <dd>Open vSwitch will not set up flows on its own when the
545 controller connection fails. It will continue retry
546 connecting to the controller forever.</dd>
549 <p>If this value is unset, the default is
550 implementation-specific.</p>
554 <group title="OpenFlow Rate Limiting">
555 <column name="controller_burst_limit">
556 In conjunction with <ref column="controller_rate_limit"/>,
557 the maximum number of unused packet credits that the bridge will
558 allow to accumulate, in packets. If not specified, the default
559 is implementation-specific.
562 <column name="controller_rate_limit">
563 <p>The maximum rate at which packets in unknown flows will be
564 forwarded to the OpenFlow controller, in packets per second. This
565 feature prevents a single bridge from overwhelming the controller.
566 If not specified, the default is implementation-specific.</p>
567 <p>In addition, when a high rate triggers rate-limiting, Open
568 vSwitch queues controller packets for each port and transmits
569 them to the controller at the configured rate. The number of
570 queued packets is limited by
571 the <ref column="controller_burst_limit"/> value. The packet
572 queue is shared fairly among the ports on a bridge.</p><p>Open
573 vSwitch maintains two such packet rate-limiters per bridge.
574 One of these applies to packets sent up to the controller
575 because they do not correspond to any flow. The other applies
576 to packets sent up to the controller by request through flow
577 actions. When both rate-limiters are filled with packets, the
578 actual rate that packets are sent to the controller is up to
579 twice the specified rate.</p>
583 <group title="Additional Configuration for Discovery">
584 <column name="discover_accept_regex">
585 If <ref column="target"/> is <code>discover</code>, a POSIX
586 extended regular expression against which the discovered controller
587 location is validated. The regular expression is implicitly
588 anchored at the beginning of the controller location string, as
589 if it begins with <code>^</code>. If not specified, the default
590 is implementation-specific.
593 <column name="discover_update_resolv_conf">
594 If <ref column="target"/> is <code>discover</code>,
595 whether to update <code>/etc/resolv.conf</code> when the
596 controller is discovered. If not specified, the default
597 is implementation-specific. Open vSwitch will only modify
598 <code>/etc/resolv.conf</code> if the DHCP response that it receives
599 specifies one or more DNS servers.
603 <group title="Additional Configuration without Discovery">
604 <column name="local_gateway">
605 If <ref column="target"/> is not <code>discover</code>, the IP
606 address of the gateway to configure on the local port.
609 <column name="local_ip">
610 If <ref column="target"/> is not <code>discover</code>, the IP
611 address to configure on the local port.
614 <column name="local_netmask">
615 If <ref column="target"/> is not <code>discover</code>, the IP
616 netmask to configure on the local port.
621 <table name="NetFlow">
622 A NetFlow target. NetFlow is a protocol that exports a number of
623 details about terminating IP flows, such as the principals involved
626 <column name="targets">
627 NetFlow targets in the form
628 <code><var>ip</var>:<var>port</var></code>. The <var>ip</var>
629 must be specified numerically, not as a DNS name.
632 <column name="engine_id">
633 Engine ID to use in NetFlow messages. Defaults to datapath index
637 <column name="engine_type">
638 Engine type to use in NetFlow messages. Defaults to datapath
639 index if not specified.
642 <column name="active_timeout">
643 The interval at which NetFlow records are sent for flows that are
644 still active, in seconds. A value of <code>0</code> requests the
645 default timeout (currently 600 seconds); a value of <code>-1</code>
646 disables active timeouts.
649 <column name="add_id_to_interface">
650 <p>If this column's value is <code>false</code>, the ingress and egress
651 interface fields of NetFlow flow records are derived from OpenFlow port
652 numbers. When it is <code>true</code>, the 7 most significant bits of
653 these fields will be replaced by the least significant 7 bits of the
654 engine id. This is useful because many NetFlow collectors do not
655 expect multiple switches to be sending messages from the same host, so
656 they do not store the engine information which could be used to
657 disambiguate the traffic.</p>
658 <p>When this option is enabled, a maximum of 508 ports are supported.</p>
663 SSL configuration for an Open_vSwitch.
665 <column name="private_key">
666 Name of a PEM file containing the private key used as the switch's
667 identity for SSL connections to the controller.
670 <column name="certificate">
671 Name of a PEM file containing a certificate, signed by the
672 certificate authority (CA) used by the controller and manager,
673 that certifies the switch's private key, identifying a trustworthy
677 <column name="ca_cert">
678 Name of a PEM file containing the CA certificate used to verify
679 that the switch is connected to a trustworthy controller.
682 <column name="bootstrap_ca_cert">
683 If set to <code>true</code>, then Open vSwitch will attempt to
684 obtain the CA certificate from the controller on its first SSL
685 connection and save it to the named PEM file. If it is successful,
686 it will immediately drop the connection and reconnect, and from then
687 on all SSL connections must be authenticated by a certificate signed
688 by the CA certificate thus obtained. <em>This option exposes the
689 SSL connection to a man-in-the-middle attack obtaining the initial
690 CA certificate.</em> It may still be useful for bootstrapping.
695 <p>An sFlow(R) target. sFlow is a protocol for remote monitoring
698 <column name="agent">
699 IP address to report as ``agent address'' to collectors. If not
700 specified, defaults to the <ref table="Controller" column="local_ip"/> in
701 the collector's <ref table="Controller"/>. If neither is specified,
705 <column name="header">
706 Number of bytes of a sampled packet to send to the collector.
707 If not specified, the default is 128 bytes.
710 <column name="polling">
711 Polling rate in seconds to send port statistics to the collector.
712 If not specified, defaults to 30 seconds.
715 <column name="sampling">
716 Rate at which packets should be sampled and sent to the collector.
717 If not specified, defaults to 400, which means one out of 400
718 packets, on average, will be sent to the collector.
721 <column name="targets">
722 sFlow targets in the form
723 <code><var>ip</var>:<var>port</var></code>.