To configure the routing locator (RLOC) address of a Locator/ID Separation Protocol (LISP) Delegated Database Tree (DDT) node
within the delegation hierarchy for which a specified EID prefix is being delegated, use the delegate command in LISP DDT authoritative mode. To remove the delegation for a specific EID prefix, use the no form of this command.
delegate {eid-prefix | instance-id iid} child-locator map-server
no delegate {eid-prefix | instance-id iid} child-locator map-server
Syntax Description
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eid-prefix
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Configures the IPv4 or IPv6 EID prefix for which the LISP DDT node is delegating authority.
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instance-id iid
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Configures a range of instance IDs or the instance ID associated with a specified EID prefix.
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child-locator
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IPv4 or IPv6 locator address of the delegation DDT node or map server.
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map-server
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Indicates that the delegated (child) DDT node being referenced is a map server for the configured IPv4 or IPv6 EID prefix.
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Command Default
A LISP DDT node is not configured to delegate authority for any EID prefixes.
Command Modes
LISP DDT authoritative (config-router-lisp-ddt-auth)
Command History
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Modification |
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15.3(1)T
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This command was introduced.
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Cisco IOS XE Release 3.8S
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This command was integrated into Cisco IOS XE Release 3.8S.
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Usage Guidelines
Use this command to configure the IPv4 or IPv6 locator address, EID prefix, and optional instance ID that is delegated to
a child DDT node within the delegation hierarchy on a parent DDT node. This enables the DDT node to send a map referral
message in response to a DDT-based map request for an EID that matches the EID prefix specified in the delegate command.
Note
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For correct hierarchical delegation, the EID prefix specified in the parent’s delegate command must match the EID prefix in the child DDT node’s ddt authoritative command
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When a DDT node receives a DDT map request, it does the following:
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The requested EID is checked for a match against any EID prefix specified in any configured ddt authoritative commands.
If there is no match, the DDT node sends a negative map referral message back to the requesting map resolver, indicating that
it is not authoritative for the EID. The map resolver caches this information and drops the map request.
If there is a match, the DDT node processing continues.
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The requested EID is checked for a match against any EID prefixes specified in any delegate commands. If the DDT node is also a map server, the EID is checked against EID prefixes specified in lisp site commands as well.
If there is no match, the DDT node sends a negative map referral message covering the coarsest negative prefix within the
configured EID prefix range for which the DDT node is authoritative. This indicates that the requested EID is within a delegation
hole and is (currently) not a LISP destination. If there is a match and the DDT node is not also a map server, the DDT node
sends a map referral message with the more specific matched EID prefix and the set of RLOCs for the delegated (child) DDT
nodes. When the configured delegate command also includes the optional map-server keyword, the returned map-referral message also indicates for the receiving map resolver that the next map request will be
to a DDT-enabled map server. If the DDT node is a map server, the map server replies with the most appropriate response to
the EID in the map request. (See the map-server-peer command for details).
When the delegate command is configured to delegate a specific LISP instance ID, or for a range of instance IDs, the optional instance-id keyword is included with the command. The value associated with the keyword will be specified as follows, depending upon
the instance ID scope being configured:
delegate child-locator instance-id iid eid-prefix eid-prefix
For a range of instance IDs, iid can either be specified in x-y format, where y must be greater than x and the range must be in a power-of-2 block (where
x is a power-of-2 and y is a power-of-2 minus 1) with a range represented by a 24-bit instance ID/mask or in IPv4 prefix format.
An EID prefix cannot be included when an instance-ID range is specified. The command is entered in either of these forms:
delegate child-locator instance-id x-y
delegate child-locator instance-id A.B.C.D/length
Note
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When a LISP DDT node is configured with a delegate command for an EID prefix or instance-ID space, the child LISP DDT node must be configured with the ddt authoritative command with a matching EID prefix and/or instance-ID space.
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Examples
The following example shows how to configure a LISP DDT node to delegate authority for the IPv4 EID prefix 172.16.0.0/16 and
the IPv6 EID prefix 2001:db8:eeee::/48 to the DDT node with child locator 10.1.1.1. Note that in this case, the instance-id keyword and value are not specified and hence, the EID prefixes are only associated with the default instance ID (0).
Device# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Device(config)# router lisp
Device(config-router-lisp)# ddt authoritative 2001:db8:eeee::/48
Device(config-router-lisp-ddt-auth)# delegate 10.1.1.1 eid-prefix 172.16.0.0/16
Device(config-router-lisp-ddt-auth)# delegate 10.1.1.1 eid-prefix 2001:db8:eeee::/48
Device(config-router-lisp-ddt-auth)#end
Device# show ddt
---<skip>---
Configured DDT delegated nodes/map-servers:
[0] 172.16.0.0/16 -> 10.1.1.1, p/w: 0/0
[0] 2001:db8:eeee::/48 -> 10.1.1.1, p/w: 0/0
In the following example, a LISP DDT node is configured to delegate authority for the IPv4 EID prefix 172.16.0.0/16 to the
DDT node with child locator 10.1.1.1 where the child is specified as a map server.
Device# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Device(config)# router lisp
Device(config-router-lisp)# ddt authoritative 2001:db8:eeee::/48
Device(config-router-lisp-ddt-auth)# delegate 10.1.1.1 eid-prefix 172.16.0.0/16 map-server
Device(config-router-lisp-ddt-auth)# end
Device# show ddt
---<skip>---
Configured DDT delegated nodes/map-servers:
[0] 172.16.0.0/16 -> 10.1.1.1, p/w: 0/0, map-server-child
In the following example, the LISP DDT node is configured to be authoritative for all EID prefixes within the instance-ID
range of 0 to 15 to the DDT node with child locator 10.1.1.1. Note that this is equivalent to using the prefix format of 0.0.0.0/28.
Device# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Device(config)# router lisp
Device(config-router-lisp)# ddt authoritative 2001:db8:eeee::/48
Device(config-router-lisp-ddt-auth)# delegate 10.1.1.1 instance-id 0-15
Device(config-router-lisp-ddt-auth)# end
Device# show ddt
---<skip>---
Configured DDT delegated nodes/map-servers:
[0-15 (0.0.0.0/28)] * -> 10.1.1.1, p/w: 0/0
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Command
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Description
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ddt
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Configures a device to enable LISP DDT functionality.
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ddt
authoritative
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Configures an extended EID prefix (instance ID and EID prefix) for which a LISP DDT node is authoritative.
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ddt
root
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Configures an IPv4 or IPv6 locator for a DDT root node within the delegation hierarchy on a DDT-enabled map resolver.
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map-server-peer
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Configures an IPv4 or IPv6 locator address and extended EID prefix (instance ID and EID prefix) for a peer map server operating
in a delegation hierarchy.
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