HP 7000 dl Router manual Copyright 2005 Hewlett-Packard Development Company, L.P 333

SROS Command Line Interface Reference Guide Global Configuration Mode Command Set

route is not received for 180 seconds, the route is marked for deletion. At that point, a 120-second garbage collection (GC) timer is started. During the GC timer, expiration updates are sent with the metric for the timed out route set to 16.

If an attached interface goes down, the associated route is immediately (within the same random five-second interval) triggered. The next regular update excludes the failed interface. This is the so-called first hand knowledge rule. If a gateway has first hand knowledge of a route failure (connected interfaces) or reestablishment, the same action is taken. A triggered update occurs, advertising the route as failed (metric = 16) or up (normal metric) followed by the normal scheduled update.

The assumption here is that if a gateway missed the triggered update, it will eventually learn from another gateway in the standard convergence process. This conserves bandwidth.

RIP-Related Definitions:

Route - A description of the path and its cost to a network. Gateway - A device that implements all or part of RIP - a router.

Hop - Metric that provides the integer distance (number of intervening gateways) to a destination network gateway.

Advertisement - A broadcast or multicast packet to port 520 that indicates the route for a given destination network.

Update - An advertisement sent on a regular 30-second interval including all routes exclusive of those learned on an interface.

5991-2114 © Copyright 2005 Hewlett-Packard Development Company, L.P. 333