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Forum Replies

  1. Hi Palani,

    It does sound conflicting yes but that’s how it works. The default route is advertised as a LSA type 3 (summary LSA) in the totally stub area. All other summary LSAs are not permitted though.


  2. Why exactly is the ABR the only one in a stub area to require the “no summary” keyword?
    I lab’d it up in GNS3 and your right the others dont need it to work and be a stub area, I was just curious as to why?
    Why dont the others in the stub area require “no summary”?

  3. Rafael,
    The difference between a Stub and a Totally Stubby Area occurs only at the ABR (the ABR determines what type of LSAs to allow into the Stub / Totally Stubby area). Since from the perspective of routers within the area there is no functional difference, there was no need to have extra information which might otherwise break the routers from forming a neighbor relationship.

  4. Rene,

    Got my response to the question which I posted in the stub area page.

    Love your work, as always…

    I have learned most of my topics by watching your gns3vault & now network lesson is to the next level.

    Kudos to you for all your efforts!

  5. Hello ,
    I have a question. When you enter ‘area 1 stub no-summary’ command what happens at the backend so that router does not forward summary LSA into the area. I mean to say how would router come to know not to forward type 3 (Summary) LSA. For example: In case of Stub area there is E bit set in Hello packet to make it stub and block type 4 and type 5 LSA. What is different for totally stub area? any additional bit or flag?

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