Neighbor and adjacency initialization

This is the very first part of OSPF operations. The router at this point will allocate memory for this function as well as for the maintenance of both the neighbor and topology tables. Once the router discovers which interfaces are configured with OSPF, it will begin sending hello packets throughout the interface in the hope of finding other routers using OSPF.

Let's look at a visual representation:

To be honest a lot more than that happens, especially since we are using Ethernet. Remember this would be considered a broadcast in between the routers so the election needs to run to choose DR and BDR, but you don't have to believe me, let me show you.

Before I configured these routers, I turned on debug ip ospf adj.

00:03:06: OSPF: DR/BDR election on FastEthernet0/0
00:03:06: OSPF: Elect BDR 10.1.1.5
00:03:06: OSPF: Elect DR 10.1.1.6...