OSPF Adjacency Process?

Hi, I understand the process that is gone through for routers configured with OSPF to become neighbors, but I don't quite understand what determines whether they progress from that and form an adjacency? thus exchanging OSPF database information.

Is it only DR's and BDR's that form adjacencies?

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Comments

DCD

Your question is vague. No you don't need a DR and BDR for adjacency. In a point-to-point network configuration doesn't use a DR and BDR for adjacency. Use this show command "show ip ospf interface faX/X. To change the network type use "ip ospf network point-to-point".

theodoxa

On a multiaccess network, routers will only proceed past 2-Way with the DR and BDR. They will not form full adjacencies with other routers. These neighbors will be listed a "DROTHER" and will only get as far as the 2-Way state. On network types that don't use a DR/BDR (point-to-point), the two routers should become fully adjacent.

james43026

Here is a really good article on the OSPF neighbor establishment process. Just too much info for lazy ole me to type out right now. Theodoxa has pointed out a key aspect of OSPF, and how OSPF routers exchange updates. It's very important.