Setting the Interval for Receiving LSAs
Context
In OSPF, the interval for receiving LSAs is 1s. 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 receiving 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-arrival-interval { interval | intelligent-timer max-interval start-interval hold-interval }
The interval for receiving LSAs is set.
- The parameter interval specifies the interval for receiving LSAs, in milliseconds.
- The parameter intelligent-timer indicates that the interval for receiving router LSAs or network LSAs is set through an intelligent timer.
- The parameter max-interval specifies the maximum interval for receiving LSAs, in milliseconds.
- The parameter start-interval specifies the initial interval for receiving LSAs, in milliseconds.
- The parameter hold-interval specifies the hold interval for receiving LSAs, in milliseconds.
On a stable network where routes need to be fast converged, you can set the interval for receiving LSAs to 0 seconds so that changes to the topology or the routes can be detected immediately.
By default, an intelligent timer is enabled. After an intelligent timer is enabled, the default maximum interval for receiving LSAs is 1000 ms, the default initial interval is 500 ms, and the default hold interval is 500 ms. Details about the interval for receiving LSAs are as follows:- The initial interval for receiving LSAs is specified by the parameter start-interval.
- The interval for receiving 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 receives LSAs at the maximum interval for three consecutive times. Then, OSPF goes back to step 3.a and receives LSAs at the initial interval specified by start-interval.
- (Optional) Run lsa-arrival-interval suppress-flapping suppress-interval [ threshold threshold ]
The maximum LSA suppression period is configured.
If frequent LSA flapping occurs, the larger value between lsa-arrival-interval suppress-flapping and lsa-arrival-interval is used to suppress LSA flapping.
By default, if the device receives an LSA, it delays route calculation for 10s.
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