Router ID election
- Manually configured Router ID in OSPF.
- If Router ID is not manually configured, the highest IP address on any of the loopback interfaces is selected as Router ID.
- If there are no loopback interfaces the highest IP address given to any active interface is selected as router ID.
Explain OSPF DR/BDR Election?
OSPF is a dynamic routing protocol. OSPF can elect one router as DR (Designated Router) and one router as BDR (Backup Designated Router).If DR fails BDR takes over. Each non-BDR or non-DR router in the network exchange routing information with DR or BDR. To send information to DR or BDR multicast IP of 224.0.0.6 is used DR sends routing information with multicast IP of 224.0.0.5.