CCIE Pursuit Blog

March 23, 2009

Core Knowledge Question of the Day: 23 March 2009

By default, OSPF floods new LSAa over all interfaces in the same area except…..

Highlight for answer: the interface that the LSA arrives on.


  1. I will go with type 7 LSA which is nssa and type 5 LSA which is for ASBR

    Comment by Vern — March 23, 2009 @ 6:52 pm | Reply

  2. i believe it should be the entry interface, the one the update came through.

    hope i am right

    Comment by nwachonky — March 24, 2009 @ 1:58 am | Reply

  3. What if LSA is originated from an ethernet segment with multiple routers attached?

    Comment by dummie — March 24, 2009 @ 6:59 am | Reply

  4. I believe the following statement to be true. This is my best guess based on what I have studied so far.

    If the LSA came in on an ethernet segment that has multiple routers attached, the recieving router would not flood back out the ethernet segment as everything else on that segment would have recieved the same original LSA. LSA forwarding is based on interface, not neighbors.

    This is the second Core Question I have actually gotten correct. Thank you for your efforts, and please keep them coming.

    Comment by scott_api — March 24, 2009 @ 9:15 am | Reply

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