About OSPF

[tosto]

Please tell me about these....

1. If a router know its interface link down,
To whom it notify problem first ? To whom second?
- DR or all router in broadcast area(I don't know)

2. why OSPF use area ?
I know RIP has not area

 

[DanielBowen]

The main reason OSPF uses areas is so that not all routers in a network have to be involved in recomputation. If OSPF only maintained a single area or AS, then each router would have to have a topological database for the entire network. In large networks, this would overburden the router. By splitting it down into multiple areas, each internal router only holds a topological database for the area that it participates in.

If an interface is down, the OSPF router will first send a TCN (topology change notification) out of all its other interfaces to whatever routers are at the end of the links (DR, ASBR or whatever). Those routers then forward the TCN out of their interfaces etc etc

Hope this has helped!

Daniel,