Setting the Interval at Which LSAs Are Updated

You can set the interval at which LSAs are updated based on network connections and router resources.

Context

OSPF sets the interval at which LSAs are updated to 5s. This prevents network connections or frequent route flapping from consuming excessive network bandwidth or device resources. On a stable network that requires fast route convergence, you can change the interval for updating LSAs to 0s. In this manner, the device can fast respond to topology or route changes, which speeds up route convergence. On an unstable network, routes are calculated frequently, which consumes a great number of CPU resources. In addition, LSPs that describe the unstable topology are generated and transmitted on the unstable network. Frequently processing such LSAs affects the rapid and stable operation of the entire network. You can configure an intelligent timer so that the device can dynamically adjust the interval according to the user configuration and the frequency of triggering events (such as route calculation) to speed network convergence.

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 ] | other-type interval [ intelligent-timer max-interval start-interval hold-interval ] }
The interval at which LSAs are updated is configured.
- intelligent-timer: Sets the intelligent timer to update OSPF Type-1 LSA (Router LSA) , Type-2 LSA (Network LSA).
- max-interval: specifies the maximum interval at which LSAs are updated, in milliseconds.
- start-interval: specifies the initial interval at which LSAs are updated, in milliseconds.
- hold-interval: specifies the hold interval at which LSAs are updated, in milliseconds.
- other-type: Sets the interval to update OSPF Type-3 LSA (Network-summary-LSA), Type-4 LSA (ASBR-summary-LSA) and Type-10 LSA (Opaque LSA).
After an intelligent timer is enabled, the interval for updating LSAs is as follows:
1. The initial interval for updating LSAs is specified by start-interval.
2. The interval for updating LSAs for the nth (n≥2) time equal hold-interval x 2^(n-2).
3. 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 updates LSAs at the initial interval specified by start-interval.
(Optional) Run lsa-originate-interval suppress-flapping suppress-interval [ threshold threshold ]
The suppression period that takes effect when the OSPF LSAs to be sent flap is configured.

If no flapping occurs among the OSPF LSAs to be sent, the configuration of the lsa-originate-interval command prevents the device from frequently sending LSAs. If the OSPF LSAs to be sent flap, the configuration of the lsa-originate-interval suppress-flapping command minimizes the impact of the flapping on services. The larger value of the two intervals specified in the commands is used as the suppression period.
Run commit
The configuration is committed.