Configuring RIP Timers

Procedure

1. Run system-view

   The system view is displayed.

2. Run rip [ process-id ]

   The RIP view is displayed.

3. Run timers rip update age garbage-collect

   RIP timers are configured.

   

   • RIP timers take effect immediately after being changed.

   • Route flapping occurs if the values of the three timers are set improperly. The relationship between the values is: update must be smaller than both age and garbage-collect. If the update time is longer than the aging time and, for example, a RIP route changes within the update time, the switch cannot inform its neighbors of the change on time.

   • Configure RIP timers based on the network performance and ensure that these timers are consistent on all RIP devices. This avoids unnecessary network traffic or route flapping.

   By default, the Update timer is 30s, the Age timer is 180s, and the Garbage-collect timer is 120s (four times the Update timer).

   In practice, the Garbage-collect timer is not fixed. If the Update timer is set to 30s, the Garbage-collect timer may range from 90s to 120s.

   Before permanently deleting an unreachable route from its RIP routing table, a RIP device advertises this route (with the metric set to 16) four times by periodically sending Update packets. Subsequently, all the neighbors learn that this route is unreachable. Because a route may not always become unreachable at the beginning of an Update period, the Garbage-collect timer ranges from three to four times the Update timer.