OSPF Over Frame-Relay: Broadcast


As the senior network engineer for a Dutch fishing company you are responsible for connecting all the different branch offices to the main network. The WAN technology you are using is Frame Relay, and you need to run OSPF over this WAN connection. You are able to broadcast on this Frame Relay link.


  • The frame-relay switch has been preconfigured for you, as you can see in the topology picture the following PVC’s has been configured:

    Router Barracuda to Salmon:
    Barracuda: DLCI 102
    Salmon: DLCI 201

    Router Barracuda to Herring:
    Barracuda: DLCI 103
    Salmon: DLCI 301

  • Router Barracuda is the “Hub” router and the other 2 routers are the “Spoke” routers.
  • Do not change any configuration on the Frame-Relay switch.
  • Configure the following IP addresses:
    Router Barracuda:
    S0/0: /24
    L0: /24

    Router Salmon:
    S0/0: /24
    L0: /24

    Router Herring:
    S0/0: /24
    L0: /24

  • Configure all serial interfaces for encapsulation Frame-Relay.
  • Disable Frame-relay inverse arp on all serial interfaces.
  • Configure the correct frame-relay map statements on all routers and make sure you can ping every IP address.
  • Configure the OSPF network type to “broadcast” on all serial interfaces.
  • Configure OSPF on all 3 routers, make sure you have full connectivity. All IP addresses including the loopbacks should be reachable.
  • You are not allowed to use the “neighbor” command in the OSPF configuration.
  • Make sure router Salmon and Herring can never be the Designated or Backup designated router.

It took me 1000s of hours reading books and doing labs, making mistakes over and over again until I mastered all the protocols for CCNP.

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OSPF over Frame-Relay Broadcast Network Topology

Video Solution:

Configuration Files

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Once you are logged in you will find the configuration files right here.

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Written by René Molenaar - CCIE #41726

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About the Author: Rene Molenaar

René - CCIE #41726 is the creator of GNS3Vault.com where he shares CCNA, CCNP and CCIE R&S labs. He also blogs about networking on http://networklessons.com


  1. Hi Renee. Need your help again.
    You are not allowed to use the "neighbor" command in the OSPF configuration.

    how do we do that ? As far as i know neighbors should be configured manually on NBMA network. Or is there any other way as well to do it?


    1. OSPF has 5 network types:

      point-to-multipoint non-broadcast

      Some of them automatically try to find neighbors…up to you to find out which one(s) 🙂

      1. This is what i understand.
        with frame-relay inverse-arp on
        broadcast (auto find neighbours)
        point-to-multipoint (auto find neighbours)
        point-to-multipoint non-broadcast
        point-to-point (auto find neighbours)

  2. Rene,

    Can you help me with an explanation on how to load your config files into GNS3?



    1. Hi Leo,

      You were able to run the topology file? Or do you just want to import the router configs?


  3. i don’t know how to download the ios image anyone to help me please…or give me tut on that please

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