Setting the Interval for Updating LSAs
Context
In OSPF, the interval for updating LSAs is defined as 5s. This aims to prevent network connections or frequent route flapping from consuming excessive network bandwidth or device resources.
On a stable network where routes need to be fast converged, you can cancel the interval for updating LSAs by setting the interval to 0 seconds. In this manner, changes to the topology or the routes can be immediately advertised on the network through LSAs, thereby speeding up route convergence on the network.
Procedure
- Run system-view
The system view is displayed.
- Run ospf [ process-id ]
The OSPF process view is displayed.
- Run lsa-originate-interval { 0 | { intelligent-timer max-interval start-interval hold-interval | other-type interval } * }
The interval for updating LSAs is set.
- The parameter intelligent-timer indicates that the interval for updating router LSAs and network LSAs is set through an intelligent timer.
- The parameter max-interval specifies the maximum interval for updating LSAs, in milliseconds.
- The parameter start-interval specifies the initial interval for updating LSAs, in milliseconds.
- The parameter hold-interval specifies the hold interval for updating LSAs, in milliseconds.
- The parameter other-type interval indicates that the interval for updating LSAs excluding Router LSAs and Network LSAs is set.
By default, an intelligent timer is enabled. After an intelligent timer is enabled, the default maximum interval for updating LSAs is 5000 ms, the default initial interval is 500 ms, and the default hold interval is 1000 ms. Details about the interval for updating LSAs are as follows:- The initial interval for updating LSAs is specified by start-interval.
- The interval for updating LSAs for the nth (n ≥ 2) time is equal to hold-interval x 2(n-2).
- When the interval specified by hold-interval x 2(n-2) reaches the maximum interval specified by max-interval, OSPF updates LSAs at the maximum interval for three consecutive times. Then, OSPF goes back to step 3.a and updates LSAs at the initial interval specified by start-interval.