1 <?xml version="1.0" encoding="utf-8"?>
2 <database title="Hardware VTEP Database">
4 This schema specifies relations that a VTEP can use to integrate
5 physical ports into logical switches maintained by a network
6 virtualization controller such as NSX.
14 VXLAN Tunnel End Point, an entity which originates and/or terminates
20 Hardware Switch Controller.
25 Network Virtualization Controller, e.g. NSX.
30 Virtual Routing and Forwarding instance.
34 <table name="Global" title="Top-level configuration.">
35 Top-level configuration for a hardware VTEP. There must be
36 exactly one record in the <ref table="Global"/> table.
38 <column name="switches">
39 The physical switches managed by the VTEP.
42 <group title="Database Configuration">
44 These columns primarily configure the database server
45 (<code>ovsdb-server</code>), not the hardware VTEP itself.
48 <column name="managers">
49 Database clients to which the database server should connect or
50 to which it should listen, along with options for how these
51 connection should be configured. See the <ref table="Manager"/>
52 table for more information.
57 <table name="Manager" title="OVSDB management connection.">
59 Configuration for a database connection to an Open vSwitch Database
64 The database server can initiate and maintain active connections
65 to remote clients. It can also listen for database connections.
68 <group title="Core Features">
69 <column name="target">
70 <p>Connection method for managers.</p>
72 The following connection methods are currently supported:
75 <dt><code>ssl:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
78 The specified SSL <var>port</var> (default: 6632) on the host at
79 the given <var>ip</var>, which must be expressed as an IP address
83 SSL key and certificate configuration happens outside the
88 <dt><code>tcp:<var>ip</var></code>[<code>:<var>port</var></code>]</dt>
90 The specified TCP <var>port</var> (default: 6632) on the host at
91 the given <var>ip</var>, which must be expressed as an IP address
94 <dt><code>pssl:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
97 Listens for SSL connections on the specified TCP <var>port</var>
98 (default: 6632). If <var>ip</var>, which must be expressed as an
99 IP address (not a DNS name), is specified, then connections are
100 restricted to the specified local IP address.
103 <dt><code>ptcp:</code>[<var>port</var>][<code>:<var>ip</var></code>]</dt>
105 Listens for connections on the specified TCP <var>port</var>
106 (default: 6632). If <var>ip</var>, which must be expressed as an
107 IP address (not a DNS name), is specified, then connections are
108 restricted to the specified local IP address.
114 <group title="Client Failure Detection and Handling">
115 <column name="max_backoff">
116 Maximum number of milliseconds to wait between connection attempts.
117 Default is implementation-specific.
120 <column name="inactivity_probe">
121 Maximum number of milliseconds of idle time on connection to the
122 client before sending an inactivity probe message. If the Open
123 vSwitch database does not communicate with the client for the
124 specified number of seconds, it will send a probe. If a
125 response is not received for the same additional amount of time,
126 the database server assumes the connection has been broken
127 and attempts to reconnect. Default is implementation-specific.
128 A value of 0 disables inactivity probes.
132 <group title="Status">
133 <column name="is_connected">
134 <code>true</code> if currently connected to this manager,
135 <code>false</code> otherwise.
138 <column name="status" key="last_error">
139 A human-readable description of the last error on the connection
140 to the manager; i.e. <code>strerror(errno)</code>. This key
141 will exist only if an error has occurred.
144 <column name="status" key="state"
145 type='{"type": "string", "enum": ["set", ["VOID", "BACKOFF", "CONNECTING", "ACTIVE", "IDLE"]]}'>
147 The state of the connection to the manager:
150 <dt><code>VOID</code></dt>
151 <dd>Connection is disabled.</dd>
153 <dt><code>BACKOFF</code></dt>
154 <dd>Attempting to reconnect at an increasing period.</dd>
156 <dt><code>CONNECTING</code></dt>
157 <dd>Attempting to connect.</dd>
159 <dt><code>ACTIVE</code></dt>
160 <dd>Connected, remote host responsive.</dd>
162 <dt><code>IDLE</code></dt>
163 <dd>Connection is idle. Waiting for response to keep-alive.</dd>
166 These values may change in the future. They are provided only for
171 <column name="status" key="sec_since_connect"
172 type='{"type": "integer", "minInteger": 0}'>
173 The amount of time since this manager last successfully connected
174 to the database (in seconds). Value is empty if manager has never
175 successfully connected.
178 <column name="status" key="sec_since_disconnect"
179 type='{"type": "integer", "minInteger": 0}'>
180 The amount of time since this manager last disconnected from the
181 database (in seconds). Value is empty if manager has never
185 <column name="status" key="locks_held">
186 Space-separated list of the names of OVSDB locks that the connection
187 holds. Omitted if the connection does not hold any locks.
190 <column name="status" key="locks_waiting">
191 Space-separated list of the names of OVSDB locks that the connection is
192 currently waiting to acquire. Omitted if the connection is not waiting
196 <column name="status" key="locks_lost">
197 Space-separated list of the names of OVSDB locks that the connection
198 has had stolen by another OVSDB client. Omitted if no locks have been
199 stolen from this connection.
202 <column name="status" key="n_connections"
203 type='{"type": "integer", "minInteger": 2}'>
205 When <ref column="target"/> specifies a connection method that
206 listens for inbound connections (e.g. <code>ptcp:</code> or
207 <code>pssl:</code>) and more than one connection is actually active,
208 the value is the number of active connections. Otherwise, this
209 key-value pair is omitted.
212 When multiple connections are active, status columns and key-value
213 pairs (other than this one) report the status of one arbitrarily
219 <group title="Connection Parameters">
221 Additional configuration for a connection between the manager
222 and the database server.
225 <column name="other_config" key="dscp"
226 type='{"type": "integer"}'>
227 The Differentiated Service Code Point (DSCP) is specified using 6 bits
228 in the Type of Service (TOS) field in the IP header. DSCP provides a
229 mechanism to classify the network traffic and provide Quality of
230 Service (QoS) on IP networks.
232 The DSCP value specified here is used when establishing the
233 connection between the manager and the database server. If no
234 value is specified, a default value of 48 is chosen. Valid DSCP
235 values must be in the range 0 to 63.
240 <table name="Physical_Switch" title="A physical switch.">
241 A physical switch that implements a VTEP.
243 <column name="ports">
244 The physical ports within the switch.
247 <column name="tunnels">
248 Tunnels created by this switch as instructed by the NVC.
251 <group title="Network Status">
252 <column name="management_ips">
253 IPv4 or IPv6 addresses at which the switch may be contacted
254 for management purposes.
257 <column name="tunnel_ips">
259 IPv4 or IPv6 addresses on which the switch may originate or
264 This column is intended to allow a <ref table="Manager"/> to
265 determine the <ref table="Physical_Switch"/> that terminates
266 the tunnel represented by a <ref table="Physical_Locator"/>.
271 <group title="Identification">
273 Symbolic name for the switch, such as its hostname.
276 <column name="description">
277 An extended description for the switch, such as its switch login
281 <group title="Error Notification">
283 An entry in this column indicates to the NVC that this switch
284 has encountered a fault. The switch must clear this column
285 when the fault has been cleared.
288 <column name="switch_fault_status" key="mac_table_exhaustion">
289 Indicates that the switch has been unable to process MAC
290 entries requested by the NVC due to lack of table resources.
293 <column name="switch_fault_status" key="tunnel_exhaustion">
294 Indicates that the switch has been unable to create tunnels
295 requested by the NVC due to lack of resources.
298 <column name="switch_fault_status" key="unspecified_fault">
299 Indicates that an error has occurred in the switch but that no
300 more specific information is available.
306 <table name="Tunnel" title="A tunnel created by a physical switch.">
307 A tunnel created by a <ref table="Physical_Switch"/>.
309 <column name="local">
310 Tunnel end-point local to the physical switch.
313 <column name="remote">
314 Tunnel end-point remote to the physical switch.
317 <group title="Bidirectional Forwarding Detection (BFD)">
319 BFD, defined in RFC 5880, allows point to point detection of
320 connectivity failures by occasional transmission of BFD control
321 messages. VTEPs are expected to implement BFD.
325 BFD operates by regularly transmitting BFD control messages at a
326 rate negotiated independently in each direction. Each endpoint
327 specifies the rate at which it expects to receive control messages,
328 and the rate at which it's willing to transmit them. An endpoint
329 which fails to receive BFD control messages for a period of three
330 times the expected reception rate will signal a connectivity
331 fault. In the case of a unidirectional connectivity issue, the
332 system not receiving BFD control messages will signal the problem
333 to its peer in the messages it transmits.
337 A hardware VTEP is expected to use BFD to determine reachability of
338 devices at the end of the tunnels with which it exchanges data. This
339 can enable the VTEP to choose a functioning service node among a set of
340 service nodes providing high availability. It also enables the NVC to
341 report the health status of tunnels.
345 In most cases the BFD peer of a hardware VTEP will be an Open vSwitch
346 instance. The Open vSwitch implementation of BFD aims to comply
347 faithfully with the requirements put forth in RFC 5880. Open vSwitch
348 does not implement the optional Authentication or ``Echo Mode''
352 <group title="BFD Local Configuration">
354 The HSC writes the key-value pairs in the
355 <ref column="bfd_config_local"/> column to specifiy the local
356 configurations to be used for BFD sessions on this tunnel.
359 <column name="bfd_config_local" key="bfd_dst_mac">
360 Set to an Ethernet address in the form
361 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>
362 to set the MAC expected as destination for received BFD packets.
365 <column name="bfd_config_local" key="bfd_dst_ip">
366 Set to an IPv4 address to set the IP address that is expected as destination
367 for received BFD packets. The default is <code>169.254.1.0</code>.
372 <group title="BFD Remote Configuration">
374 The <ref column="bfd_config_remote"/> column is the remote
375 counterpart of the <ref column="bfd_config_local"/> column.
376 The NVC writes the key-value pairs in this column.
379 <column name="bfd_config_remote" key="bfd_dst_mac">
380 Set to an Ethernet address in the form
381 <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>
382 to set the destination MAC to be used for transmitted BFD packets.
383 The default is <code>00:23:20:00:00:01</code>.
386 <column name="bfd_config_remote" key="bfd_dst_ip">
387 Set to an IPv4 address to set the IP address used as destination
388 for transmitted BFD packets. The default is <code>169.254.1.1</code>.
393 <group title="BFD Parameters">
395 The NVC sets up key-value pairs in the <ref column="bfd_params"/>
396 column to enable and configure BFD.
399 <column name="bfd_params" key="enable" type='{"type": "boolean"}'>
400 True to enable BFD on this tunnel.
403 <column name="bfd_params" key="min_rx"
404 type='{"type": "integer", "minInteger": 1}'>
405 The shortest interval, in milliseconds, at which this BFD session
406 offers to receive BFD control messages. The remote endpoint may
407 choose to send messages at a slower rate. Defaults to
411 <column name="bfd_params" key="min_tx"
412 type='{"type": "integer", "minInteger": 1}'>
413 The shortest interval, in milliseconds, at which this BFD session is
414 willing to transmit BFD control messages. Messages will actually be
415 transmitted at a slower rate if the remote endpoint is not willing to
416 receive as quickly as specified. Defaults to <code>100</code>.
419 <column name="bfd_params" key="decay_min_rx" type='{"type": "integer"}'>
420 An alternate receive interval, in milliseconds, that must be greater
421 than or equal to <ref column="bfd" key="min_rx"/>. The
422 implementation switches from <ref column="bfd" key="min_rx"/> to <ref
423 column="bfd" key="decay_min_rx"/> when there is no obvious incoming
424 data traffic at the interface, to reduce the CPU and bandwidth cost
425 of monitoring an idle interface. This feature may be disabled by
426 setting a value of 0. This feature is reset whenever <ref
427 column="bfd" key="decay_min_rx"/> or <ref column="bfd" key="min_rx"/>
431 <column name="bfd_params" key="forwarding_if_rx" type='{"type": "boolean"}'>
432 True to consider the interface capable of packet I/O as long as it
433 continues to receive any packets (not just BFD packets). This
434 prevents link congestion that causes consecutive BFD control packets
435 to be lost from marking the interface down.
438 <column name="bfd_params" key="cpath_down" type='{"type": "boolean"}'>
439 Set to true to notify the remote endpoint that traffic should not be
440 forwarded to this system for some reason other than a connectivty
441 failure on the interface being monitored. The typical underlying
442 reason is ``concatenated path down,'' that is, that connectivity
443 beyond the local system is down. Defaults to false.
446 <column name="bfd_params" key="check_tnl_key" type='{"type": "boolean"}'>
447 Set to true to make BFD accept only control messages with a tunnel
448 key of zero. By default, BFD accepts control messages with any
454 <group title="BFD Status">
456 The VTEP sets key-value pairs in the <ref column="bfd_status"/>
457 column to report the status of BFD on this tunnel. When BFD is
458 not enabled, with <ref column="bfd_params" key="enable"/>, the
459 HSC clears all key-value pairs from <ref column="bfd_status"/>.
462 <column name="bfd_status" key="state"
463 type='{"type": "string",
464 "enum": ["set", ["admin_down", "down", "init", "up"]]}'>
465 Reports the state of the BFD session. The BFD session is fully
466 healthy and negotiated if <code>UP</code>.
469 <column name="bfd_status" key="forwarding" type='{"type": "boolean"}'>
470 Reports whether the BFD session believes this tunnel
471 may be used to forward traffic. Typically this means the local session
472 is signaling <code>UP</code>, and the remote system isn't signaling a
473 problem such as concatenated path down.
476 <column name="bfd_status" key="diagnostic">
477 In case of a problem, set to an error message that reports what the
478 local BFD session thinks is wrong. The error messages are defined
479 in section 4.1 of [RFC 5880].
482 <column name="bfd_status" key="remote_state"
483 type='{"type": "string",
484 "enum": ["set", ["admin_down", "down", "init", "up"]]}'>
485 Reports the state of the remote endpoint's BFD session.
488 <column name="bfd_status" key="remote_diagnostic">
489 In case of a problem, set to an error message that reports what the
490 remote endpoint's BFD session thinks is wrong. The error messages
491 are defined in section 4.1 of [RFC 5880].
497 <table name="Physical_Port" title="A port within a physical switch.">
498 A port within a <ref table="Physical_Switch"/>.
500 <column name="vlan_bindings">
501 Identifies how VLANs on the physical port are bound to logical switches.
502 If, for example, the map contains a (VLAN, logical switch) pair, a packet
503 that arrives on the port in the VLAN is considered to belong to the
504 paired logical switch.
507 <column name="vlan_stats">
508 Statistics for VLANs bound to logical switches on the physical port. An
509 implementation that fully supports such statistics would populate this
510 column with a mapping for every VLAN that is bound in <ref
511 column="vlan_bindings"/>. An implementation that does not support such
512 statistics or only partially supports them would not populate this column
513 or partially populate it, respectively.
516 <group title="Identification">
518 Symbolic name for the port. The name ought to be unique within a given
519 <ref table="Physical_Switch"/>, but the database is not capable of
523 <column name="description">
524 An extended description for the port.
527 <group title="Error Notification">
529 An entry in this column indicates to the NVC that the physical port has
530 encountered a fault. The switch must clear this column when the errror
533 <column name="port_fault_status" key="invalid_vlan_map">
535 Indicates that a VLAN-to-logical-switch mapping requested by
536 the controller could not be instantiated by the switch
537 because of a conflict with local configuration.
540 <column name="port_fault_status" key="unspecified_fault">
542 Indicates that an error has occurred on the port but that no
543 more specific information is available.
550 <table name="Logical_Binding_Stats" title="Statistics for a VLAN on a physical port bound to a logical network.">
551 Reports statistics for the <ref table="Logical_Switch"/> with which a VLAN
552 on a <ref table="Physical_Port"/> is associated.
554 <group title="Statistics">
555 These statistics count only packets to which the binding applies.
557 <column name="packets_from_local">
558 Number of packets sent by the <ref table="Physical_Switch"/>.
561 <column name="bytes_from_local">
562 Number of bytes in packets sent by the <ref table="Physical_Switch"/>.
565 <column name="packets_to_local">
566 Number of packets received by the <ref table="Physical_Switch"/>.
569 <column name="bytes_to_local">
570 Number of bytes in packets received by the <ref
571 table="Physical_Switch"/>.
576 <table name="Logical_Switch" title="A layer-2 domain.">
577 A logical Ethernet switch, whose implementation may span physical and
578 virtual media, possibly crossing L3 domains via tunnels; a logical layer-2
579 domain; an Ethernet broadcast domain.
583 <group title="Per Logical-Switch Tunnel Key">
585 Tunnel protocols tend to have a field that allows the tunnel
586 to be partitioned into sub-tunnels: VXLAN has a VNI, GRE and
587 STT have a key, CAPWAP has a WSI, and so on. We call these
588 generically ``tunnel keys.'' Given that one needs to use a
589 tunnel key at all, there are at least two reasonable ways to
596 Per <ref table="Logical_Switch"/>+<ref table="Physical_Locator"/>
597 pair. That is, each logical switch may be assigned a different
598 tunnel key on every <ref table="Physical_Locator"/>. This model is
603 In this model, <ref table="Physical_Locator"/> carries the tunnel
604 key. Therefore, one <ref table="Physical_Locator"/> record will
605 exist for each logical switch carried at a given IP destination.
611 Per <ref table="Logical_Switch"/>. That is, every tunnel
612 associated with a particular logical switch carries the same tunnel
613 key, regardless of the <ref table="Physical_Locator"/> to which the
614 tunnel is addressed. This model may ease switch implementation
615 because it imposes fewer requirements on the hardware datapath.
619 In this model, <ref table="Logical_Switch"/> carries the tunnel
620 key. Therefore, one <ref table="Physical_Locator"/> record will
621 exist for each IP destination.
626 <column name="tunnel_key">
628 This column is used only in the tunnel key per <ref
629 table="Logical_Switch"/> model (see above), because only in that
630 model is there a tunnel key associated with a logical switch.
634 For <code>vxlan_over_ipv4</code> encapsulation, this column
635 is the VXLAN VNI that identifies a logical switch. It must
636 be in the range 0 to 16,777,215.
641 <group title="Identification">
643 Symbolic name for the logical switch.
646 <column name="description">
647 An extended description for the logical switch, such as its switch
653 <table name="Ucast_Macs_Local" title="Unicast MACs (local)">
655 Mapping of unicast MAC addresses to tunnels (physical
656 locators). This table is written by the HSC, so it contains the
657 MAC addresses that have been learned on physical ports by a
662 A MAC address that has been learned by the VTEP.
665 <column name="logical_switch">
666 The Logical switch to which this mapping applies.
669 <column name="locator">
670 The physical locator to be used to reach this MAC address. In
671 this table, the physical locator will be one of the tunnel IP
672 addresses of the appropriate VTEP.
675 <column name="ipaddr">
676 The IP address to which this MAC corresponds. Optional field for
677 the purpose of ARP supression.
682 <table name="Ucast_Macs_Remote" title="Unicast MACs (remote)">
684 Mapping of unicast MAC addresses to tunnels (physical
685 locators). This table is written by the NVC, so it contains the
686 MAC addresses that the NVC has learned. These include VM MAC
687 addresses, in which case the physical locators will be
688 hypervisor IP addresses. The NVC will also report MACs that it
689 has learned from other HSCs in the network, in which case the
690 physical locators will be tunnel IP addresses of the
695 A MAC address that has been learned by the NVC.
698 <column name="logical_switch">
699 The Logical switch to which this mapping applies.
702 <column name="locator">
703 The physical locator to be used to reach this MAC address. In
704 this table, the physical locator will be either a hypervisor IP
705 address or a tunnel IP addresses of another VTEP.
708 <column name="ipaddr">
709 The IP address to which this MAC corresponds. Optional field for
710 the purpose of ARP supression.
715 <table name="Mcast_Macs_Local" title="Multicast MACs (local)">
717 Mapping of multicast MAC addresses to tunnels (physical
718 locators). This table is written by the HSC, so it contains the
719 MAC addresses that have been learned on physical ports by a
720 VTEP. These may be learned by IGMP snooping, for example. This
721 table also specifies how to handle unknown unicast and broadcast packets.
726 A MAC address that has been learned by the VTEP.
729 The keyword <code>unknown-dst</code> is used as a special
730 ``Ethernet address'' that indicates the locations to which
731 packets in a logical switch whose destination addresses do not
732 otherwise appear in <ref table="Ucast_Macs_Local"/> (for
733 unicast addresses) or <ref table="Mcast_Macs_Local"/> (for
734 multicast addresses) should be sent.
738 <column name="logical_switch">
739 The Logical switch to which this mapping applies.
742 <column name="locator_set">
743 The physical locator set to be used to reach this MAC address. In
744 this table, the physical locator set will be contain one or more tunnel IP
745 addresses of the appropriate VTEP(s).
750 <table name="Mcast_Macs_Remote" title="Multicast MACs (remote)">
752 Mapping of multicast MAC addresses to tunnels (physical
753 locators). This table is written by the NVC, so it contains the
754 MAC addresses that the NVC has learned. This
755 table also specifies how to handle unknown unicast and broadcast
759 Multicast packet replication may be handled by a service node,
760 in which case the physical locators will be IP addresses of
761 service nodes. If the VTEP supports replication onto multiple
762 tunnels, then this may be used to replicate directly onto
763 VTEP-hyperisor tunnels.
768 A MAC address that has been learned by the NVC.
771 The keyword <code>unknown-dst</code> is used as a special
772 ``Ethernet address'' that indicates the locations to which
773 packets in a logical switch whose destination addresses do not
774 otherwise appear in <ref table="Ucast_Macs_Remote"/> (for
775 unicast addresses) or <ref table="Mcast_Macs_Remote"/> (for
776 multicast addresses) should be sent.
780 <column name="logical_switch">
781 The Logical switch to which this mapping applies.
784 <column name="locator_set">
785 The physical locator set to be used to reach this MAC address. In
786 this table, the physical locator set will be either a service node IP
787 address or a set of tunnel IP addresses of hypervisors (and
788 potentially other VTEPs).
791 <column name="ipaddr">
792 The IP address to which this MAC corresponds. Optional field for
793 the purpose of ARP supression.
798 <table name="Logical_Router" title="A logical L3 router.">
800 A logical router, or VRF. A logical router may be connected to one or more
801 logical switches. Subnet addresses and interface addresses may be configured on the
805 <column name="switch_binding">
806 Maps from an IPv4 or IPv6 address prefix in CIDR notation to a
807 logical switch. Multiple prefixes may map to the same switch. By
808 writing a 32-bit (or 128-bit for v6) address with a /N prefix
809 length, both the router's interface address and the subnet
810 prefix can be configured. For example, 192.68.1.1/24 creates a
811 /24 subnet for the logical switch attached to the interface and
812 assigns the address 192.68.1.1 to the router interface.
815 <column name="static_routes">
816 One or more static routes, mapping IP prefixes to next hop IP addresses.
819 <group title="Identification">
821 Symbolic name for the logical router.
824 <column name="description">
825 An extended description for the logical router.
830 <table name="Arp_Sources_Local" title="ARP source addresses for logical routers">
832 MAC address to be used when a VTEP issues ARP requests on behalf
837 A distributed logical router is implemented by a set of VTEPs
838 (both hardware VTEPs and vswitches). In order for a given VTEP
839 to populate the local ARP cache for a logical router, it issues
840 ARP requests with a source MAC address that is unique to the VTEP. A
841 single per-VTEP MAC can be re-used across all logical
842 networks. This table contains the MACs that are used by the
843 VTEPs of a given HSC. The table provides the mapping from MAC to
844 physical locator for each VTEP so that replies to the ARP
845 requests can be sent back to the correct VTEP using the
846 appropriate physical locator.
849 <column name="src_mac">
850 The source MAC to be used by a given VTEP.
853 <column name="locator">
854 The <ref table="Physical_Locator"/> to use for replies to ARP
855 requests from this MAC address.
859 <table name="Arp_Sources_Remote" title="ARP source addresses for logical routers">
861 MAC address to be used when a remote VTEP issues ARP requests on behalf
866 This table is the remote counterpart of <ref
867 table="Arp_sources_local"/>. The NVC writes this table to notify
868 the HSC of the MACs that will be used by remote VTEPs when they
869 issue ARP requests on behalf of a distributed logical router.
872 <column name="src_mac">
873 The source MAC to be used by a given VTEP.
876 <column name="locator">
877 The <ref table="Physical_Locator"/> to use for replies to ARP
878 requests from this MAC address.
882 <table name="Physical_Locator_Set">
884 A set of one or more <ref table="Physical_Locator"/>s.
888 This table exists only because OVSDB does not have a way to
889 express the type ``map from string to one or more <ref
890 table="Physical_Locator"/> records.''
893 <column name="locators"/>
896 <table name="Physical_Locator">
898 Identifies an endpoint to which logical switch traffic may be
899 encapsulated and forwarded.
903 For the <code>vxlan_over_ipv4</code> encapsulation, the only
904 encapsulation defined so far, all endpoints associated with a given <ref
905 table="Logical_Switch"/> must use a common tunnel key, which is carried
906 in the <ref table="Logical_Switch" column="tunnel_key"/> column of <ref
907 table="Logical_Switch"/>.
911 For some encapsulations yet to be defined, we expect <ref
912 table="Physical_Locator"/> to identify both an endpoint and a tunnel key.
913 When the first such encapsulation is defined, we expect to add a
914 ``tunnel_key'' column to <ref table="Physical_Locator"/> to allow the
915 tunnel key to be defined.
919 See the ``Per Logical-Switch Tunnel Key'' section in the <ref
920 table="Logical_Switch"/> table for further discussion of the model.
923 <column name="encapsulation_type">
924 The type of tunneling encapsulation.
927 <column name="dst_ip">
929 For <code>vxlan_over_ipv4</code> encapsulation, the IPv4 address of the
930 VXLAN tunnel endpoint.
934 We expect that this column could be used for IPv4 or IPv6 addresses in
935 encapsulations to be introduced later.