OSPF Broadcast Network Type over Frame-Relay

[lagapidis (Lazarus Agapidis)]

Hello Ali

The OSPF network type you use should be appropriate for the network topology in question. Yes, frame-relay is not something used very much any longer, but there are other network topologies that may use a network type other than the broadcast network type which is the default for Ethernet interfaces.

DMVPN is a prime example of a topology that can use different network types. You can see examples of how they are used in the following lessons:
https://networklessons.com/cisco/ccie-enterprise-infrastructuredmvpn-phase-1-ospf-routing
https://networklessons.com/cisco/ccie-enterprise-infrastructuredmvpn-phase-2-ospf-routing
https://networklessons.com/cisco/ccie-enterprise-infrastructuredmvpn-phase-3-ospf-routing

I assume your question here has to do with the hub and spoke topology you mention in another one of your posts. You can see the response to that post here:

OSPF Non-Broadcast Network Type over Frame-Relay

Hello Ali First of all, having 60 OSPF routers in a single broadcast domain will cause you problems. And if I understand correctly, you have a hub and spoke topology, so all of the remote routers are listening to broadcast traffic on this single subnet over their WAN connections. So you’re using up bandwidth unnecessarily, and you are also causing the routers to look at broadcasts that do not belong to them, so they continually discard them. The best way to resolve this issue is not to choos…

I hope this has been helpful!

Laz