Products

Description

Information About Locator/ID Separation Protocol
The Locator/ID Separation Protocol (LISP) network architecture and protocol implements a new semantic for IP addressing by creating two new namespaces: Endpoint Identifiers (EIDs), which are assigned to end hosts, and Routing Locators (RLOCs), which are assigned to devices (primarily routers) that make up the global routing system. Splitting EID and RLOC functions improves routing system scalability, multihoming efficiency, and ingress traffic engineering. LISP end site support is configured on devices such as Cisco routers.

Information About LISP
In the current Internet routing and addressing architecture, the IP address is used as a single namespace that simultaneously expresses two functions about a device: its identity and how it is attached to the network. One very visible and detrimental result of this single namespace is demonstrated by the rapid growth of the Internet’s default-free zone (DFZ) as a consequence of multi-homing, traffic engineering (TE), non­aggregatable address allocations, and business events such as mergers and acquisitions.

LISP changes current IP address semantics by creating two new namespaces: Endpoint Identifiers (EIDs) that are assigned to end-hosts and Routing Locators (RLOCs) that are assigned to devices (primarily routers) that make up the global routing system. These two namespaces provide the following advantages:

Improved routing system scalability by using topologically aggregated RLOCs

Provider independence for devices numbered out of the EID space

Multihoming of endsites with improved traffic engineering

IPv6 transition functionality

LISP is deployed primarily in network edge devices. It requires no changes to host stacks, Domain Name Service (DNS), or local network infrastructure, and little to no major changes to existing network infrastructure

LISP Infrastructure
The LISP infrastructure devices are as follows:

Map Server (MS)—This device is deployed as a LISP Infrastructure component. It must be configured to permit a LISP site to register to it by specifying for each LISP site the EID prefixes for which registering ETRs are authoritative. An authentication key must match the key that is configured on the ETR. An MS receives Map-Register control packets from ETRs. When the MS is configured with a service interface to the LISP ALT, it injects aggregates for the EID prefixes for registered ETRs into the ALT. The MS also receives Map-Request control packets from the ALT, which it then encapsulates to the registered ETR that is authoritative for the EID prefix being queried.

Map Resolver (MR)—This device is deployed as a LISP Infrastructure device. It receives Map-Requests encapsulated to it from ITRs. When configured with a service interface to the LISP ALT, the MR forwards Map Requests to the ALT. The MR also sends Negative Map-Replies to ITRs in response to queries for non-LISP addresses.

Alternative Topology (ALT)—This is a logical topology and is deployed as part of the LISP Infrastructure to provide scalable EID prefix aggregation. Because the ALT is deployed as a dual-stack (IPv4 and IPv6) Border Gateway Protocol (BGP) over Generic Routing Encapsulation (GRE) tunnels, you can use ALT-only devices with basic router hardware or other off-the-shelf devices that can support BGP and GRE.

LISP Internetworking Devices
The LISP internetworking devices are as follows:

Proxy ITR (PITR)—This device is a LISP infrastructure device that provides connectivity between non-LISP sites and LISP sites. A PITR advertises coarse-aggregate prefixes for the LISP EID namespace into the Internet, which attracts non-LISP traffic destined to LISP sites. The PITR then encapsulates and forwards this traffic to LISP sites. This process not only facilitates LISP/non-LISP internetworking but also allows LISP sites to see LISP ingress traffic engineering benefits from non-LISP traffic.

Proxy ETR (PETR)—This device is a LISP infrastructure device that allows IPv6 LISP sites without native IPv6 RLOC connectivity to reach LISP sites that only have IPv6 RLOC connectivity. In addition, the PETR can also be used to allow LISP sites with Unicast Reverse Path Forwarding (URPF) restrictions to reach non-LISP sites.