7 Replies Latest reply: Jun 9, 2019 12:08 AM by Samer RSS

    OSPF network type


      Hi all,

      Does 2 OSPF form a full adjacency if one has the connected interface's network type different from the other?

      I have a topology:

      (loopback ---- (f0/0)R2(loopback

      Config OSPF on both, but change network type of f0/0 on R1 into point-to-point.

      I see that;

      R1 and R2 can form FULL/- adjacency relationship.

      R2 claims to be DR and see R1 as BDR.

      R1 still see R2 as a neighbor connected via point-to-point link.


      R1 and R2 don't learn routes advertised by each other.


      In CCNA route (page 504), I see that 2 OSPF router only form neighbor relationship only if 3 parameters match with each others.


      In Hello packet, there is no field represent network type. How can received router determine which network type interface of neighbor are?