Is it possible to obtain a WAN IPv6 address within one of the delegated subnets?



  • I'm currently getting a nice 61 bit PD (8 subnets) from Comcast.

    LAN is tracking prefix 0, DMZ is tracking prefix 1 and GUEST is tracking prefix 2.

    Is it possible, using DHCPv6 advanced client configuration on the WAN interface to obtain an address within one of the delegated subnets (say prefix ID 7)?



  • @mircolino:

    Is it possible, using DHCPv6 advanced client configuration on the WAN interface to obtain an address within one of the delegated subnets (say prefix ID 7)?

    No, ISP territory is their gate, for you. You have look on the LAN side for that. Prefix /61 is delegated to You to manage LAN.
    A WAN number is not necessarily needed for your public exposure. Test your understanding with configgin Static LAN i.s.o. using Track Interface ? Just issue the subnet numbers, like "7", manual for public (LAN's) exposure.



  • I posted about this last year, https://forum.pfsense.org/index.php?topic=115300.0. pfSense does not support this.

    According to TR-124 (Issue 5 is the latest), it's a mandatory requirement for a residential gateway to create for itself a globally-scoped address out of its delegated prefix if the edge router does not create such an address for it.

    Here is the quote:

    WAN.IPv6. 12 If the RG does not have a globally-scoped address on its WAN
    interface after having been delegated a prefix, it MUST create
    addresses for itself from the delegated prefix. It MUST have at
    least one address and MAY have more.
    There is currently no algorithm defined for address creation. It
    should be assumed that different service providers will want
    different rules for how to create the address, how many addresses
    to create, and in the case of multiple addresses, how the different
    addresses are used.

    My residential gateway allocates its global WAN address in prefix+ff/64, using RFC 2464. (My ISP allocates a /56 prefix, hence the +ff.)



  • I should add, it's not obvious what the purpose of a WAN address on a residential gateway is. Possibly for the ISP to perform firmware updates. In the case of my gateway, it does not respond to ping.