IPv6 behind Xfinity gateway



  • Hello everyone, after many hours I'm left lost, tired and frustrated. I hope someone can link to information which could allow some progress in my quest to get IPv6 working behind my pfsense firewall. Here is my situation:

    I've recently switched from using my own modem (IPv6 worked great) to using xfinity gateway (cheaper unlimited data plan) the issue is that gateway does not request anything other than one /64 IPv6 block, which it uses for itself (seemingly no way to disable / redirect it).

    First I've tried to use the tried DHCP6 & track tunnel methods with /64 prefix size, my WAN would get a single IPv6, but LAN & subsequent computers would not.

    Than I've tried to get IPv6 tunnel (from HE.net) working, but the gateway shows offline when DNS server is set as a Monitor IP. I've done the process over and over looking for issues, but IPv6 seems to be intercepted on the Xfinity level, even though the WAN IP of the pfsense is set as DMZ endpoint. Settings are as close to the guide (link) as I could make it, given that some interfaces were updated since than.

    Lastly I've spent a ton of time trying to get NPt working with idea of creating a local /64 IPv6 name block (fc00:#::) and remap it to the existing /64 IPv6 block on the WAN side. Alas I'm still new to the NPt concept and could not find a reasonable guide as to how make full use out of it.

    I really do not want to drop pfsense for my LAN just to get access to IPv6.

    Thank you for the time to share your experiences, I'm willing to try anything suggested, I'm up the creek without a paddle at this point.



  • @ebsense

    Can you put that modem into bridge mode? With my ISP, if I have the modem in gateway mode, I get a single /64. But with it in bridge mode, I can get a /56.



  • Alas, the new xfinity / comcast gateway does not appear to have an option for a bridge mode on a residential service. I've looked through every option I could find, bridge was nowhere to be found.

    Found the option within "At a Glance" page, which I've skipped so many times I became blind to it. With it I can get a /60 network from ISP, too bad I have to choose between this and having a backup gateway in case pfsense goes down (during server maintenance usually).

    On the positive note my pings went down by half! ✌

    It is frustrating that protocol 41 (IPv6 encapsulation) appears to be blocked / dropped somewhere upstream. Otherwise IPv6 tunnel would have already solved my issues.


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