Here are the four timers that IP RIP uses to regulate its performance:
- Route update timer Time between router updates. The default is 30 seconds.
- Route invalid timer Time that must expire before a route becomes invalid. The default is 180 seconds.
- Route hold-down timer If IP RIP receives an update with a hop count higher than the metric recorded in the routing table, the router goes into holddown for 180 seconds.
- Route flush timer Time from when a route becomes invalid to when it is removed from the routing table. The default is 240 seconds.
Sometimes you do not want RIP updates to propagate across the WAN, wasting valuable bandwidth or giving out valuable information about your internetwork. The easiest way to stop RIP updates from propagating out an interface is to use the passive-interface global configuration command.
The show ip route command displays the Cisco routing table's contents.
IGRP is a Cisco proprietary distance vector routing protocol. IGRP has a default hop count of 100 hops, with a maximum hop count of 255. IGRP uses bandwidth and line delay as its default metric, but it can also use reliability, load, and MTU.