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  • #2198300

    Rip – Classful subnets

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    by neuralping ·

    Using Boson NetSim 6 simulator – Lab 6 RIP. The simulator clearly states RIP has to have classful network number. However,There are a couple of classless network numbers being used on routers 3 and 4. Router 3 would not advertise routes when using a classful network of 197.10.0.0. What am I missing. Can rip use classless network numbers?

    Router1
    network 160.10.0.0
    network 175.10.0.0

    Router2
    network 160.10.0.0

    Router3
    network 175.10.0.0
    network 180.10.0.0
    network 197.10.1.0

    Router4
    network 180.10.0.0
    network 195.10.1.0

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    • #2832765

      Clarifications

      by neuralping ·

      In reply to Rip – Classful subnets

      Clarifications

    • #2832757

      Version 2 supports VLSM, & Classless

      by cg it ·

      In reply to Rip – Classful subnets

      Version 1 doesn’t. Version1 is stricktly classful.

      • #2832690

        RIP – Classfull subnets

        by neuralping ·

        In reply to Version 2 supports VLSM, & Classless

        I saw documentation where RIPv1 does not send subnet mask information when advertising routes which is the reason why you need to use classful networks numbers. The strange thing is Router 4 advertising network 195.10.1.0 gets sent out to the other routers with no problem. Just router 3 with network 197.10.1.0 won’t advertise when it’s classless. I watched using debug ip rip and it never got sent out but on router 4 195.10.1.0 gets advertised.

    • #2831580

      Could you explain

      by netman1958 ·

      In reply to Rip – Classful subnets

      Why you say “However, There are a couple of classless network numbers being used on routers 3 and 4”

      I’m not saying you are wrong as I don’t have that NetSim you are using so I can’t see everything you see. I am curious though.

      Also, you might be interested in this article:
      http://www.cisco.com/application/pdf/paws/13724/55.pdf

      The take-away is that if RIPv1 advertises a route across a major network boundry then it automatically summarizes it. However, if it advertises the route across a link that is part of the same major network, then it sends the subnet mask also.

      For example:
      172.16.1.0/24 -> 172.20.1.0/24 -> 172.16.2.0/24
      The router advertising 172.16.1.0/24 summarizes the route to 172.16.0.0

      However:
      172.16.1.0/24 -> 172.16.3.0/24 -> 172.16.2.0/24
      The router advertising 172.16.1.0 sends the route as 172.16.1.0 255.255.255.0

      • #2831542

        Guy mentioned Classless RIPv1 is classful

        by cg it ·

        In reply to Could you explain

        if he’s doing VLSM, RIPv2

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