Stability issues in OSPF routing [A

We study the stability of the OSPF protocol under steady state and perturbed conditions. We look at three indicators of stability, namely, (a) network convergence times, (b) routing load on proces-sors, and (c) the number of route flaps. We study these statistics under three different scenarios: (a) on networks that deploy OSPF with TE extensions, (b) on networks that use subsecond HELLO timers, and (c) on networks that use alternative strategies for re-freshing link-state information. Our results are based on a very detailed simulation of a real ISP network with 292 nodes and 765 links. 1