LISP ITR Graceful Restart
draft-saucez-lisp-itr-graceful-03

Abstract

The Locator/ID Separation Protocol (LISP) is a map-and-encap mechanism to enable communications between hosts identified with their Endpoint IDentifier (EID) over the Internet where EIDs are not routable. To do so, packets toward EIDs are encapsulated in packets with routing locators (RLOCs) to form dynamic tunnels. An Ingress Tunnel Router (ITR) that encapsulates EID packets determines tunnel endpoints via mappings that associate EIDs to RLOCs. Before encapsulating a packet, the ITR queries the mapping system to obtain the mapping associated to the EID of the packet it must encapsulate. Such mapping is cached by the ITR in its local EID-to-RLOC cache for any subsequent encapsulation for the same EID. LISP is scalable because EID-to-RLOC mappings are cached on ITRs. Initially, the cache is empty and is populated progressively according to the traffic traversing the ITR. However, after an ITR is restarted, e.g., for maintenance reason, its cache is empty which means that all packets that are re-routed to the freshly restarted ITR will cause cache misses and a potentially high loss rate. In this draft, we present mechanisms to reduce the negative impact on traffic caused by the restart of an ITR in a LISP network.

Authors

Damien Saucez
Olivier Bonaventure
Luigi Iannone
Clarence Filsfils

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)