Terminology
- Routing Locator (RLOC): A RLOC is an IPv4 or IPv6 address of an egress tunnel router (ETR). A RLOC is the output of an EID-to-RLOC mapping lookup.
- Endpoint ID (EID): An EID is an IPv4 or IPv6 address used in the source and destination address fields of the first (most inner) LISP header of a packet.
- Egress Tunnel Router (ETR): An ETR is a router that accepts an IP packet where the destination address in the "outer" IP header is one of its own RLOCs. ETR functionality does not have to be limited to a router device. A server host can be the endpoint of a LISP tunnel as well.
- Ingress Tunnel Router (ITR): An ITR receives IP packets from site end-systems on one side and sends LISP-encapsulated IP packets toward the Internet on the other side.
- Proxy ETR (PETR): A PETR is used for inter-networking between LISP and Non-LISP sites, a PETR acts like an ETR but does so on behalf of LISP sites which send packets to destinations at non-LISP sites.
- Proxy ITR (PITR): A PITR is used for inter-networking between Non-LISP and LISP sites, a PITR acts like an ITR but does so on behalf of non-LISP sites which send packets to destinations at LISP sites.
- xTR: A xTR is a reference to an ITR or ETR when direction of data flow is not part of the context description. xTR refers to the router that is the tunnel endpoint.
Read more about this topic: Locator/Identifier Separation Protocol, LISP