OSPF neighbors


In OSPF, routers have to become neighbors first before exchanging link- state advertisements (LSA).After configuring OSPF on routers it will start sending hello packets to each other.The Hello packets also serve as keepalives to allow routers to quickly discover if a neighbor is down. Hello packets also contain a neighbor field that lists the Router IDs of all neighbors the router is connected to.

OSPF routers will only become neighbors if the following parameters within a Hello packet are identical on each router: 

  • Area ID 
  • Subnet Mask 
  • Hello Interval 
  • Dead Interval 
  • Authentication 
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4 comments:

  1. STUB flag should match for OSPF routers to become neighbors.

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  2. Subnet mask? Can you elaborate this part please?

    ReplyDelete
    Replies
    1. Both interfaces should have same subnet mask

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