Improve OSPF convergence

Dear Friend! Hope it can help you:

OSPF convergence speed is affected by the following factors:

- A device detects that the peer link is down and the neighbor relationship becomes invalid.
- A new link-state advertisement (LSA) is generated and flooded.
- The Link State Database (LSDB) is updated. A new route is calculated through the Shortest Path First (SPF) routing algorithm and delivered to the Forwarding Information Base (FIB) table.
For faster OSPF convergence, you can adjust the following options on the switch:

- Shorten the hello interval and dead interval of the neighbor, or configure Bidirectional Forwarding Detection (BFD) for fast failure detection.
- Run the spf-schedule-interval command to set a shorter time interval between two SPF algorithm operations (five seconds by default).
- Shorten the LSA generation interval.
- Shorten the interval of detecting LSA arrival.
- On the interface, run the ospf trans-delay command to speed up the flooding of LSAs.

Thanks!