Configuring OSPF packet timers
You can configure the following timers on OSPF interfaces as needed.
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. The poll interval is at least four times the hello interval.
Dead timer—Interval within which if the interface receives no hello packet from the neighbor, it declares the neighbor is down. The dead interval must be at least four times the hello interval on an interface.
LSA retransmission timer—Interval within which if the interface receives no acknowledgement packets after sending an LSA to the neighbor, it retransmits the LSA. An 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.
To configure timers for OSPF packets:
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 | Optional. The hello interval defaults to 10 seconds on P2P and broadcast interfaces, and defaults to 30 seconds on P2MP and NBMA interfaces. The default hello interval is restored when the network type for an interface is changed. |
4. Specify the poll interval. | ospf timer poll seconds | Optional. The poll interval defaults to 120 seconds. |
5. Specify the dead interval. | ospf timer dead seconds | Optional. The default dead interval is 40 seconds on P2P and broadcast interfaces and 120 seconds on P2MP and NBMA interfaces. The default dead interval is restored when the network type for an interface is changed. |
6. Specify the retransmission interval. | ospf timer retransmit interval | Optional. The retransmission interval defaults to 5 seconds. |