1 Reply Latest reply on Oct 3, 2018 2:53 PM by lhoffer

    OSPF Area Type

    HassanAlKak88 Expert
    vExpert

      Hello,

       

      Kindly advise between the different use cases of use the Normal or NSSA type. and what is the difference between them.

       

       

      Thanks in advance,

        • 1. Re: OSPF Area Type
          lhoffer Hot Shot
          vExpertVMware Employees

          You can find all the specifics on how an NSSA is different in the RFC at http://www.ietf.org/rfc/rfc1587.txt, but the main difference is whether you want to see external routes (normal area type) or not (NSSA/stub areas rely mainly default/summary routes and while they do have the ability to use external routes, there's not a great use case for that that I've seen in NSX).

           

          Typically it comes down to whether or not you want the area to be able act as transit or not so the most common scenario for NSX is if you're in a large datacenter running OSPF, the ESG uplinks for your NSX environment are typically going to connect to the backbone (normal) area, but since the downstream DLRs don't care about the upstream datacenter topology (which could be very complex/large), the ESG downlinks and DLRs could be part of an NSSA so that the only routes seen by the DLRs would be advertisements from other DLRs in the NSSA and a default route out the ESGs.