ipv4 alt-vrf
To configure which virtual routing and forwarding (VRF) instance supporting the IPv4 address-family that Locator/ID Separation Protocol (LISP) should use when sending map requests for an IPv4 endpoint identifier-to-routing locator ( EID-to-RLOC) mapping directly over the alternative logical topology (ALT), use the ipv4 alt-vrf command in LISP configuration mode. To remove this reference to a VRF, use the no form of this command.
ipv4 alt-vrf vrf-name
no ipv4 alt-vrf [ vrf-name]
Syntax Description
vrf-name |
Name assigned to the ALT VRF. |
Command Default
By default, no ALT VRF is referenced by LISP.
Command Modes
LISP configuration (config-router-lisp)
Command History
Release |
Modification |
---|---|
15.1(1)XB1 |
This command was introduced. |
Cisco IOS XE Release 2.5.1XA |
This command was integrated into Cisco IOS XE Release 2.5.1XA. |
Cisco IOS XE Release 3.3.0S |
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the ip keyword was changed to ipv4 , and the lisp keyword was removed from the command syntax. |
15.1(4)M |
This command was modified. Support for this command was removed at the global configuration level and added for LISP configuration mode. Also, the ip keyword was changed to ipv4 , and the lisp keyword was removed from the command syntax. |
Usage Guidelines
The ipv4 alt-vrf command is required for all LISP devices that are connected to the ALT for exchange of LISP control plane messages for IPv4 EID mapping resolution. The VRF instance specified using the ipv4 alt-vrf command is used to segment EID prefixes from the global table and must be configured to enable the IPv4 address family (use the ipv6 alt-vrf command to enable the IPv6 address family).
Additionally, you must use the ipv4 alt-vrf command (or ipv6 alt-vrf command for IPv6 EID mapping resolution) when configuring any LISP device as a map resolver (MR), map server (MS), or proxy ingress tunnel router (PITR). For these LISP devices, configuring the ipv4 alt-vrf or ipv6 alt-vrf command is required regardless whether the device is connected to an ALT for the exchange of map requests or is configured as a standalone MR, MS, PITR, or any combination of the three (such as when a LISP MS/MR device has full knowledge of the LISP mapping system for a private LISP deployment and is not connected to any ALT).
When configuring a device as a LISP ingress tunnel router (ITR) to resolve IPv4 EID-to-RLOC mappings for destination EIDs, you can configure the device to use one of the following two options:
-
Send map requests to a map resolver—the ITR sends map requests in a LISP encapsulated control message (ECM) header with either an IPv4 or IPv6 map-resolver RLOC as its destination address (depending on the configuration). For this option, use the ipv4 itr map-resolver command instead of the ipv4 alt-vrf command.
-
Send map requests directly over the LISP ALT using the VRF instance specified when configuring this command—the ITR sends map requests directly over the ALT (without the additional LISP ECM header). The destination of the map request is the EID being queried. For this option, use the ipv4 alt-vrf command.
When using the ALT, you must configure the correct address family (IPv4 or IPv6) for resolving EID-to-RLOC mappings. If an IPv4 EID mapping is required, configure the ipv4 alt-vrf command and specify a VRF that enables the IPv4 address-family and connects to an IPv4-capable ALT.
Note |
Before this command is used, the referenced VRF must already have been created using the vrf definition command. In addition, the corresponding configurations for connecting the LISP device to the ALT, including the GRE tunnel interfaces and any routing associated with the VRF (static or dynamic) must also have been created. |
Examples
The following example shows how to configure the VRF named lisp and how to configure LISP to use this VRF when resolving IPv4 EID-to-RLOC mappings:
Router (config)# router lisp
Router(config-router-lisp)# vrf definition lisp
Router(config-vrf)# rd 65100:100
Router(config-vrf)# address-family ipv4
Router(config-vrf-af)# exit-address-family
Router(config-vrf)# exit
Router(config)# router lisp
Router(config-router-lisp)# ipv4 alt-vrf lisp