Optimal Configuration of OSPF Aggregates

—Open Shortest Path First (OSPF) is a popular protocol for routing within an autonomous system (AS) domain. In order to scale for large networks containing hundreds and thousands of subnets, OSPF supports a two-level hierarchical routing scheme through the use of OSPF areas. Subnet addresses within an area are aggregated, and this aggregation is a crucial requirement for scaling OSPF to large AS domains, as it results in significant reductions in routing table sizes, smaller link-state databases, and less network traffic to synchronize the router link-state databases. On the other hand, address aggregation also implies loss of information about the length of the shortest path to each subnet, which in turn, can lead to suboptimal routing. In this paper, we address the important practical problem of configuring OSPF aggregates to minimize the error in OSPF shortest-path computations due to subnet aggregation. We first develop an optimal dynamic programming algorithm that, given an uppe...

• Type: Conference
• Year: 2002
• Where: INFOCOM
• Authors: Rajeev Rastogi, Yuri Breitbart, Minos N. Garofalakis, Amit Kumar
• Keywords: Communications, INFOCOM 2002, OSPF, OSPF Aggregates, Shortest Paths