IPv6 Configuration on FR network

Hi All,


While going through one of the senerio in which I am having three routers connected in Hub-n-Spoke while hub has serial connection having multipoint connection to spokes.


Lets consider like Below:





ROUTER A connected to ROUTER B and ROUTER C with a multipoint physical port.


I wanted to configure IPv6 with OSPF but got stuck when I wanted to map link-local address as can't find the two address pointing to different DLCI? I really appreciate if anyone can help me to understand this so that I can make it.

Thanks and Regards



  • Hi

    IMHO I think you may need to create two fame maps on RTRA to router B & C's local link address as well as remote IPV6 interface address. Do same on routers B C back to rtr A's local link address and IPV6 interface address. Think you may need to map the OSPFv3 multicast address also FF02::5 & FF02::6.

    Maybe debug IPV6 pkt detail.. See if encapsulation still fails?


    Good Luck



  • You won't need to try and map the multicast addresses.  Multicasts are still multicasts.  Even in IPv6.  So as long as you have the broadcast key word on the frame maps, they should get sent out all configured DLCIs on the OSFP interface.  Besides... you can't map the same address to multiple DLCIs on an interface (unless someone knows something that I don't).


  • HI Von,


    Thanks for writing back, well as for laeyr 3 to layer 2 mapping is concern so I believe we must map link-local address along with DLCI and given IP address and similar for IPv6. Actually what exactly issue I am facing here is ,


    1. when I do have only one physical point having only one IPv6 address so how it will generate two link-local address corresponding to ROUTER B and ROUTER C and vice versa from each router.


    I really appreciate if anyone could help me to understand how can I accomplish this task.


    Thanks and Regards

  • You will not be mapping the same address to two DLCIs...because it is inverse mapping (local dlci and far end ipv6 add)

    Make it easy on yourself and define the link local address on each FR interface

    Router A Config

    int s0/0/0

    ipv6 add 2001..........::1/64

    ipv6 add fe80::1 link local              <--- define Router A link Local address

    frame-relay map ipv6 fe80::2 102 bro      <----map to Router B link local dlci 102

    frame-relay map ipv6 2001.....::2  102 bro 

    frame-relay map ipv6 fe80::3 103 bro      <----map to Router C link local dlci 103

    frame-relay map ipv6 2001.....::3  103 bro





       U dont need to add broadcast keyword both on the link local and ipv6 address. The broadcast keyword here means "Set Multicast Capability". Usually adding only to the link local is better. The ipv6 over frame-relay over ospfv3 had the same concepts with ipv4 of FR over ospf. If u have true understand of OSPF and Frame-Realy for IPv4, dont worry, use debug and show commands for that technologies and correct all the issues.


  • Jeriel your right...but in the lab exam, I dont think it matters...unless the lab says it matters.  Especially when your struggling with the basics of what to map per the original post. 

    Let them get the basis down where one can meet the requirements of 50% of
    the possible tasks then add on.

    If your asked to run the default network type (non-broadcast) with
    "ipv6 ospf neighbor fe80::x" then of course you don't need the
    keyword at all as you say just like in ospfv2. However will having them on break anything?

    IMHO...sometimes "best practices" cause more harm then good in the
    lab.  Meaning that in the lab its not going to hurt to have the broadcast
    keywords on either the ipv4 and ipv6 maps, but 1. it might cost me 10-15 seconds to remember where to put them or
    not put (like in the case of non-broadcast above)  .2. a later IPV4
    multicast task might require the broadcast keyword to be  in place on
    your IPv4 maps even if OSPF didn't require it can save a little heart burn and
    another few minutes.

  • You don't need to map the link local addresses between router B and router C. Router A should have two link local maps, one for Router B and One for Router C. Router B should only have a link local map for router A, and Router C should only have a link local map for Router A as well.

    Use the broadcast keyword on the link local mappings, for routing protocols that use multicast.

    Map all of the global or site local IPv6 address as you would for IPv4. 

    If you are using OSPFv3 try to add a neighbor statement for for the global/site address and IOS will inform you that you need to use the link local address.

    If you don't know the distant ends link local, then disable route-cache on the interface and debug IPv6 packet. I did that on a couple of the IE labs because I didn't know the what the BB router was using as a link local address, and don't want to have to telnet to the BB since that option may or may not be available in the real lab.

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