Lisp Map-Server; Lisp Rtr - Cisco Nexus 7000 Series Configuration Manual

Overview of LISP Support for Disjointed RLOC Domains
domains. In traditional routing architectures, providing connectivity between disjointed routing domains can
be quite complex.
The inherent property of LISP, which separates IP addresses into two address spaces, gives it the ability to
connect disjointed RLOC domains through simplified configuration mechanisms. The key components are
new control plane configuration options on the LISP Map-Server, and the Re-encapsulating Tunnel Router
(RTR) function, which provides data plane connectivity between disjointed locator spaces. The components
and the workflow are explained.

LISP Map-Server

When a LISP site registers with the Map-Server, it provides RLOC information. Ensure that all relevant
RLOCs are registered with the Map-Server. Map-Server configurations are required to enable connectivity
across RLOC spaces.
A device with IOS XE software is used for the role of Map-Server. For more information, see IP Routing:
Note
LISP Configuration Guide, Cisco IOS XE Release 3S.

LISP RTR

An RTR provides data plane communications support for LISP to LISP traffic between LISP sites that do not
share common locator space. Functionally, an RTR takes in LISP encapsulated packets from an Ingress Tunnel
Router (ITR) in one locator scope, decapsulates them, checks the map-cache, and then re-encapsulates them
to an Egress Tunnel Router (ETR) in another locator scope. The following are important considerations for
an RTR:
• RTR should have RLOCs in all locator scopes that are being joined.
• An RTR sends Map-Request messages to populate its map-cache. As a Map-Request message contains
an ITR RLOC field that is populated with one or more entries corresponding to the locators of the device
sending the Map-Request message, locator set configuration is required on the RTR to define its locators.
This enables the Map-Server to correctly receive Map-Request messages from the RTR to assess locator
scope connectivity.
• Since an RTR performs functions similar to a Proxy Ingress Tunnel Router (PITR) and Proxy Egress
Tunnel Router (PETR), the PITR and PETR features must be enabled on the RTR.
Cisco Nexus 7000 Series device is used for the PxTR (a device performing PITR and PETR functions)
Note
and RTR functions.
Cisco Nexus 7000 Series NX-OS VXLAN Configuration Guide
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LISP Support for Disjointed RLOC Domains