OSPF Forwarding Address
The forwarding address appears as part of the information associated with the LSAs found within the OSPF database. It's an optional field in the OSPF external link advertisements which specifies the next hop IP address to which packets for the advertised destination should be sent.
- For a particular LSA, data traffic for the advertised destination will be forwarded to this address.
- If the forwarding address is set to 0.0.0.0, data traffic will be forwarded instead to the advertisement’s originator.
Why is this useful? It allows for more efficient routing in some cases. For example, if multiple routers have paths to the same external network, they can all advertise the same Forwarding Address, which can reduce the number of routes that other routers need to maintain.
Links:
https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/25493-type5-lsa.html