RLOC Routing locators

RLOC (Routing Locator) is a term used in the context of the Locator/ID Separation Protocol (LISP). LISP is an architecture that separates the roles of endpoint identifiers (EIDs) and routing locators (RLOCs) to enable scalable and efficient routing in large networks, such as the Internet.

In traditional IP routing, the IP address serves as both the endpoint identifier and the routing locator. However, this approach has limitations when it comes to mobility, multihoming, and network scalability. LISP solves these issues by introducing the concept of RLOCs.

Routing locators (RLOCs) are network addresses used for routing and forwarding traffic within a LISP-enabled network. They are used to represent the location or topological information of devices in the network. RLOCs are assigned to network elements such as routers, switches, or any other LISP-capable device.

When a device wants to send data to another device in a LISP network, it needs to resolve the endpoint identifier (EID) of the destination into one or more RLOCs. This process is known as mapping. The mapping is typically done through a Mapping System, which maintains the mapping database that associates EIDs with their corresponding RLOCs.

Once the source device obtains the RLOCs for the destination EID, it can encapsulate the data packets with a LISP header. The LISP header includes the source and destination RLOCs, as well as other information needed for routing and encapsulation purposes. This encapsulated packet is then forwarded based on the RLOCs, allowing the LISP network to efficiently route the traffic.

RLOCs are typically assigned based on the underlying network topology, and they can be either globally routable addresses or private addresses. The selection of RLOCs can be influenced by various factors, including network policies, load balancing requirements, and traffic engineering considerations.

One of the key benefits of using RLOCs in LISP is that they can remain stable even when the endpoint identifier (EID) of a device changes due to mobility or network renumbering. This decoupling of EIDs and RLOCs enables devices to maintain connectivity even when their location or network attachment point changes.

In summary, RLOCs are routing locators used in the Locator/ID Separation Protocol (LISP) to represent the topological information of devices in a LISP-enabled network. They are used for routing and forwarding traffic, and they provide scalability, mobility, and multihoming benefits to the network architecture.