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Enabling Dynamic Routing Protocol (EIGRP) n production network

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  • Enabling Dynamic Routing Protocol (EIGRP) n production network

    Hi All,

    I have to enable EIGRP on my network whcih is working with static routing now. I am attaching the Network Diagram and the details of the requirement.

    I have 2x6509E Core switches, 2 routers and 3 WAN links.

    Router 1 - Link 1 - MPLS Router from Telco 4Mb
    Core Switch01- Link 2 - DLL Link (Private Link)
    Router 2 - Link 3 - 2 Mb DLL line from Telco

    Now i need to run EIGRP routing protocol from Core Switches. I want to make the Link 1 as the primary route for user range and Link 2 as the back up. Link 1 as the backup for the server ip range in my network and Link 2 as the Primary.
    Link 3 as the back up for both servers and users.

    if you need any more information please do let me know.

    Attached Files

  • #2
    Re: Enabling Dynamic Routing Protocol (EIGRP) n production network

    Lol, I can help you but Im not going to do the work for you. The best thing to do is take things in steps.

    1. Get Eigrp up between the Core switches
    2. Make sure you have your adjacencies established and that routes are being passed between the two devices.
    3. Your going to have to do some traffic engineering to get the routing the way you want it. Eigrp uses bandwidth and delay as its metric. It's up to you but I usually take bandwidth out of the mix when working with eigrp and just use delay. It makes Eigrp a little easier to work with and plus if you have any Qos going on changing bandwidth values will effect Eigrp as well as any othter Qos mechanisms. You can change the eigrp metric calculation with the "metric weights command under the Eigrp process. Be advised that the metrics must match to form an adjacency. If your not running any Qos then the standard metric shouldnt be an issue. I would definately define the bandwith on the interaces. ie If you have a 4mb metro line configure the bandwidth on the interface for 4mb etc.

    eigrp 1
    metric weights 0 0 0 1 0 0 - That will make eigrp just use delay in microseconds

    Once Eigrp is up between the Core switches then you can move ahead and enable it elsewhere. Eigrp is NOT a plug and play protocol so be carefull. Stuck in Active routes are common if not designed properly. I would definatley do some research with Eigrp before attempting this. Its not something you just want to rush into. With that being said once its up and running and stable you can change delay values, filter, summarize, policy route etc.
    Last edited by auglan; 2nd June 2010, 14:02.
    CCNA, CCNA-Security, CCNP
    CCIE Security (In Progress)


    • #3
      Re: Enabling Dynamic Routing Protocol (EIGRP) n production network

      Hi Friends,

      I know this is not an easy task, especially for me since I havent played much in dynamic routing protocols other than in my old CCNP labs. Also it is a production network and the requirement from the customer is much complicated too.
      At each sites I have 2x6509E Core switches, 2 routers and 3 WAN links.

      Router 1 - Link 1 - MPLS Link from Telco 4Mb
      Core Switch01- Link 2 - Private Link on Tunnel Interface
      Router 2 - Link 3 - 2 Mb DLL Link from Telco

      Before I start i would like mention one thing that, i have a doubt about the WAN Link 2 (Private Link), that the parent organisation, who is the owner of the private link, is using Eigrp at their huge backbone. If they use Eigrp then i may have to change my protocol to some thing other right?

      I need to check with them and I will update about this ASAP.

      As suggested, I am breaking down my task in to multiple steps.

      Kindly find some time to reveiw this and correct me if i am wrong or i am missing some thing, also help with your inputs.

      Task 1) Running EIGRP / OSPF in the Core Switch-1 and 2 at site-1 and then site-2. (All are under same AS or Area 0)

      Task 2) Running EIGRP / OSPF in the WAN Router-1 and 2 at site-1 and site-2

      Task 3) Redistribute EIGRP / OSPF route in to Telco BGP and Redistribute BGP in to EIGRP / OSPF at WAN Router-1 (4Mb MPLS Link Router) at site-1 and site-2.
      (need some help on the redistribution part)

      Task 4) I want to give first preference to the 4 Mb MPLS Link, any traffic originating from my user LAN at site-1 going to any where in Site-2 should take the 4 Mb MPLS Link first. And if this fails all traffic should pass to Link2 on Core Switch-1 (Private Link on Tunnel Interface). (need clarity on how to do this task)

      (I guess, since it is a redistributed route this will be an external route for the EIGRP / OSPF domain. WAN Link-3 at Router-2 (2Mb DLL Link) is a point-to-point link and chances are there to get prefernce for this route)

      Task 5) The WAN Link-2, which is terminated at Core Switch-1 at Site-1 and Core Switch1- at Site-2. As of now, I am using a PBR on the Core switch-1 and pushing all traffic originating from my server ip range (192.168.50.x/24) at site-1 going to server ip range (192.168.100.x/24) at site 2 to this Link.

      After implementing the routing I want this link remians as the primary for the server to server communication between site-1 and site-2. Also should work as a backup link incase Link-1 (4Mb MPLS Link) failed. All traffic at that point should flow through this link.
      (need clarity on how to do this task)

      Task 6) In worst case if both Link 1 (4 Mb MPLS Link in Router-1) and Link-2 (Private Link on Tunnel interface in Core Switch-1) are failed the whole traffic should go to the 3rd Link in WAN Router-2 (2 Mb DLL Link).
      (need clarity on how to do this task)

      Dear friends, i know that it is a huge list of task and is not easy too, i need your kind help in this, i know how worthy your inputs on this, kindly find some time to work with me on this, i need your kind support please.

      Apreciate your valuable inputs.

      Thanks and regards
      Last edited by jacobsamuel2021; 3rd June 2010, 10:18.


      • #4
        Re: Enabling Dynamic Routing Protocol (EIGRP) n production network

        You can run eigrp as well if you want under a different AS or you can run ospf and then redistribute into eigrp. The first thing you need to do is decide what routing protocols you are going to run. Once you decide then you need to implement it. With this being a production network it would have to be after hours or during sheduled downtime. The traffic engineering will come in after your routing domain is stable with whichever protocols you decide to run. Im a little confused about the private link. You said that they already run EIGRP on one side of it? If so then you can just run eigrp and setup a peering with them. Also you mention the tunnel interface. Is this a GRE tunnel? If so then you need to watch for recursive routing failures via the tunnel. As far as redistribution goes I dont know where it needs to be applied but there are some general rules to follow. With redistribution on one router you shouldnt have any issues with route feedback. There however may be some sub optimal routing issues. The problem comes in when you are redistributing at several points and where loops are possible. Remember that the router/switch can only redistribute routes it uses (ie routes in the routing table and any connected interfaces covered in the network statement) Before redistribution occurs you should know what routes you will get on the other protocol and then you can adjust accordingly.

        As far as redistributing bgp into the IGP that is up to you. Is this MPLS circuit for internet or MPLS VPN. If vpn then yeah not a big deal just redistribute BGP into your igp so you local clients have reachability to the remote subnets. If it is an internet connection then just be aware that the internet BGP table is over 200,000 routes so you may want to think that one through.

        Like I said there is no sense thinking about traffic engineering until you get your IGP stable. There are many ways to get traffic to route the way you want it such as metric manipulation, policy routing etc. The first thing you need to do is get whatever IGP you going to use in place and make sure the routing domain is stable (No loops, flaps etc)
        CCNA, CCNA-Security, CCNP
        CCIE Security (In Progress)


        • #5
          Re: Enabling Dynamic Routing Protocol (EIGRP) n production network

          Hi Auglan,

          Thanks a lot for the reply.

          Regarding the Private Link, the link belongs to an organization whcih is connecting the Gov offices across the country. This network is huge and bigger than a normal ISP. Most probably they will not allow us to peer with their EIGRP domian.

          Regardng the he Tunnel, yes it is a GRE Tunnel only.

          About redistribution, i think we need to do redistribution at 2 places. One for sure at the WAN Router1-the MPLS BGP (the MPLS circuit is a MPLS VPN only). Second if we have to use another Dynamic Routing Protcol other than EIGRP, we need to do redistribution in the Core Switch01 which is connecting to the Private Link with their EIGRP.

          I have to do the first 3 Task to make the IGP routing for my network. I am sure that my customer will force me to do route the user traffic to mpls link and server traffic to private link. I need to be ready for the, traffic engineering immediatly once it is done.

          I am preparing the configuration for the internal routing now. I will send the configuration files if you could pleaes share your email address, to verify my configuration.

          Thanks a lot for the helping hand dear friend.

          Last edited by Wired; 7th June 2010, 01:27. Reason: unless you like spam, I wouldn't suggest posting your email address