Introduction to OSPF Stub Areas

[lagapidis (Lazarus Agapidis)]

Hello Chandra

OSPF uses two multicast addresses, specifically, 224.0.0.5 for all OSPF routers, and 224.0.0.6 for all Designated routers. These addresses are used to exchange hello packets and LSAs. Which address is used for which purpose depends on the network topology and the implementation of OSPF. Take a look at this post for more info.

OSPF Packets and Neighbor Discovery

Hello Markos Concerning question 1, there is no clear cut answer given for the destination IP address for DBDs from DROTHER routers in the RFC2328 describing OSPFv2. It states what kinds of packets use what kind of address (unicast/multicast) except for the DBD. Take a look at Pages 58-59 on the RFC. However, researching further, there seems to be a consensus that the DBD packets are sent to the unicast addresses of the DR and BDR. Now according to the RFC: On physical point-to-point netw…

I hope this has been helpful!

Laz