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CPE IPv6 Issue - Draytek

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  • 1.  CPE IPv6 Issue - Draytek

    Posted 07-13-2018 08:53



    I have been testing IPv6 on our CPE devices that will be supplied to customer on the DSL subscriber side.


    After great help from Rahul I have the technicolor CPE working correctly on IANA. However, our customers will require different CPE devices and we have to test them all.


    So, the next CPE we needed to test is a Draytek 2760. When we booted this CPE it got the correct IPv4 from the RADIUS but it is not getting the correct IPv6 address wwe assign from the RADIUS (the Technicolor does get the correct address). Has anyone seen an issue on the Draytek regarding IPv6? I have tried their forums with no luck.


    Any help would be much appreciated.



  • 2.  RE: CPE IPv6 Issue - Draytek
    Best Answer

    Posted 07-13-2018 09:07

    Hi Clive,


    Please configure router-advertisement under the dynamic-profile.


    protocols {

        router-advertisement {

            interface "$junos-interface-name" {


                dns-server-address 2001:4860:4860::8844;

                dns-server-address 2001:4860:4860::8888;

                prefix $junos-ipv6-ndra-prefix;





    You need to configure /64 pool or you can return /64 framed-ipv6-prefix. This will help us to identify if CPE is looking for NDRA+DHCPv6 PD or DHCPv6 IANA+PD.



  • 3.  RE: CPE IPv6 Issue - Draytek

    Posted 07-16-2018 02:57

    Hi Rahul,


    I will configure this later and complete some tests, for the moment we have another issue we are trying to resolve that I will ask in another topic.

  • 4.  RE: CPE IPv6 Issue - Draytek

    Posted 07-17-2018 06:49

    Hi Rahul,


    We now have the Draytek working with NDRA thanks to your superb help.


    However, we do have 1 issue that is maybe working as it should or, is not.


    The actual end node (laptop) seems to be keeping its IPv6 address from previous configurations. In other words, I configure the RADIUS for IANA using /128 and a PD of /56. The CPE gets the correct address and delegates /64 prefixs on the LAN. The laptop on the LAN gets an IPv6 address and that's fine. 


    I then connect an NDRA CPE and reconfigure the RADIUS with a /64 and a /56 for PD and change the addressing to test. Now I find the laptop has the old address AND the new address assigned to the interface. The IPv6 testing still works, but here is the question:


    Why are all the addresses staying on the laptop?



  • 5.  RE: CPE IPv6 Issue - Draytek

    Posted 07-17-2018 07:05

    It's okay. It's a windows thing it would seem. And only 1 address is public even with an infinite time. And the public one adheres to the DHCP timers, so all is good.


    Thanks Rahul.