I have an query, that when OSPF uses multicast or unicast address after two-way state??
Bcz I just setup an topology, attached below...
& after saw the O/P of wireshark my head is like going to burst...
As u can see in O/P of Wireshark (both interfaces of R1). OSPF uses unicast messages for DBD exchange b/w R1 & R4 (via. Ethernat link). & uses multicast messages for same b/w R1 & R5 (via Serial link).
That's interesting, but it depends on a few things. What are the OSPF network types? Can you show the configuration for each interface?
Can you share the configuration ?
Please check if it like below:
For on P2P links Hellos and LSAs are sent via multicast and on P2MP links they are sent via unicast.
Can you share router's configuration?
I think one of the networks is configured like non-broadcast with neighbor command under ospf configuration.
This may take some time. I'll send it after few hours..
Attached is running config of all three Routers.
As you can see in run-config, link b/w R1 & R4 is configured as Broadcast & link b/w R1 & R5 is configured as Point-2-Point.
I have done many pcap upon this.