Configuring RIPng Timers

Procedure

1. Run system-view

   The system view is displayed.

2. Run ripng [ process-id ] [ vpn-instance vpn-instance-name ]

   The RIPng process is enabled and the RIPng view is displayed.

3. Run timers ripng update age garbage-collect

   RIPng timers are configured.

   

   • RIPng 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 age and garbage-collect. If the update time is longer than the aging time and for example, a RIPng route changes within the update time, the switch cannot inform its neighbors of the change on time.

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

   By default, the Update timer is 30s; the Age timer is 180s; 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 RIPng routing table, a RIPng 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 or four times the Update timer.