Configuring OSPF timers
An OSPF interface includes the following timers:
Hello timer—Interval for sending hello packets. It must be identical on OSPF neighbors.
Poll timer—Interval for sending hello packets to a neighbor that is down on the NBMA network.
Dead timer—Interval within which if the interface does not receive any hello packet from the neighbor, it declares the neighbor is down.
LSA retransmission timer—Interval within which if the interface does not receive any acknowledgment packets after sending an LSA to the neighbor, it retransmits the LSA.
To configure OSPF timers:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface interface-type interface-number | N/A |
3. Specify the hello interval. | ospf timer hello seconds | By default:
The default hello interval is restored when the network type for an interface is changed. |
4. Specify the poll interval. | ospf timer poll seconds | The default setting is 120 seconds. The poll interval is at least four times the hello interval. |
5. Specify the dead interval. | ospf timer dead seconds | By default:
The dead interval must be at least four times the hello interval on an interface. The default dead interval is restored when the network type for an interface is changed. |
6. Specify the retransmission interval. | ospf timer retransmit interval | The default setting is 5 seconds. A retransmission interval setting that is too small can cause unnecessary LSA retransmissions. This interval is typically set bigger than the round-trip time of a packet between two neighbors. |