RIP Timers
RIP uses four kinds of timers to regulate its performance; Table 3.8 describes them.
Table 3.9 lists the commands to change the timers:
TABLE 3 . 8 RIP Timers
Timer Meaning
route update timer Sets the interval (typically 30 seconds) between periodic routing
updates, in which the router sends a complete copy of its routing
table to all neighbors.
route invalid timer Determines the length of time that must elapse (180 seconds) before
a router determines that a route has become invalid. It will come to
this conclusion if it hasn’t heard any updates about a particular route
for that period. When that happens, the router will send out updates
to all its neighbors letting them know that the route is invalid.
holddown timer This sets the amount of time during which routing information is suppressed.
Routes will enter into the holddown state when an update
packet is received that indicates the route is unreachable. This continues
either until an update packet is received with a better metric or
until the holddown timer expires. The default is 180 seconds.
route flush timer Sets the time between a route becoming invalid and its removal
from the routing table (240 seconds). Before it’s removed from the
table, the router notifies its neighbors of that route’s impending
demise. The value of the route invalid timer must be less than that
of the route flush timer. This gives the router enough time to tell its
neighbors about the invalid route before the local routing table is
updated.