FIRE: Flexible intra-AS routing environment

Current routing protocols art: monolithic, specifying the algorithm used to construct forwarding tables, the metric used by the algorithm (generally s ome form of hop-count), and the protocol used to distribute these metrics a s an integrated package. The Flexible Intra-AS Routing Environment (FIRE) i s a link-state, intra-domain routing protocol that decouples these componen ts. FIRE supports run-time-programmable algorithms and metrics over a secur e link-state distribution protocol. By allowing the network operator to dyn amically reprogram both the information being advertised and the routing al gorithm used to construct forwarding tables in Java, FIRE enables the devel opment and deployment of novel routing algorithms without the need for a ne w protocol to distribute state. FIRE supports multiple concurrent routing a lgorithms and metrics, each constructing separate forwarding tables. By usi ng operator-specified packet filters, separate classes of traffic are route d using completely different routing algorithms, all supported by a single routing protocol. This paper presents an overview of FIRE, focusing particularly on FIRE's no vel aspects with respect to traditional routing protocols. We also briefly describe our implementation experience.