IPv6 not functional (Spectrum/Charter)

[karvec]

Hello all,

I decided to jump into IPv6 today and have been fighting it literally all day.  After reading multiple guides, howtos, forums, bug reports, etc I decided that I wasn't completely crazy, so I reached out to my ISP via chat and they were completely useless.  (Spectrum/Charter).   Reading their website, they say that IPv4 and 6 are running concurrently in a dual stack configuration, so my assumption is both *SHOULD* work.  However upon further reading, their entire network is IPv4 and to make IPv6 work it's basically "ymmv".

I've been testing every change I make by ping -4 google.com, ping -6 google.com straight from my router (OPNsense 25.1) and the -4 worked every time, however I never got a response on -6.  I finally gave up, unplugged the router, verified IPv6 was turned on on my desktop, and went ahead and unplugged the network cable from my modem and plugged directly into my desktop (bypassing the router completely.)  I had to power cycle the modem, and it gave me a different external IPv4 address than my router normally had.  At this point, I checked my connection details and had an IPv4 address and IPv6 gateway and link-local address.  I checked on test-ipv6.com and got 0/10 on the score.

Am I correct in assuming that Spectrum is complete trash and doesn't have any implementation of IPv6 in their stack other than an IPv4to6/6to4 on the edge of their network and that's why I can't pass any IPv6 traffic?

Thanks all.  My config for WAN interface is DHCPv6, Prefix size /56, Send prefix hint.  Have tested with VLAN priorities, different prefix delegation size (/60, /64), optional prefix ID, each time testing and checking IPv6 connectivity directly from the router to google/wherever and absolutely no luck.

[franco]

You can enable debugging for DHCPv6 on WAN (Interfaces: Settings) logged in system general log by "dhcp6c" you can see if the ISP even bothers responding which I think they do not. The reasons for that could be plenty. Some have MAC locks, others forget to configure their clients or break the network somewhere in between.


Cheers,
Franco

[karvec]

Yeah, I had already enabled it and was watching the scroll for the longest time.  Just a lot of "dhcp6c send solicit to ff02::1:2%igb0" with no reply.  I believe that is the correct address the solicit is supposed to go out to?

I plan on trying to filter this so I can see if there are any replies from the ISP, but according to dhcp6c there have been none.  Considering the fact restarting the modem plugged straight into my computer issued me a fresh IPv4 address, I would assume that with Windows IPv6 enabled I would have received a routable IPv6 address straight from the ISP.  So either 2 of my devices (router + windows desktop) are sending the wrong requests to the ISP or my ISP is not responding to IPv6 solicits.

Any other suggestions to continue down the troubleshooting path?

I've since updated OPNsense to 25.7, so not sure if I should repost this there or if a mod can move it for me.

Thanks!

~karvec

[franco]

> Just a lot of "dhcp6c send solicit to ff02::1:2%igb0" with no reply.

Yep, that's what I suspected. Nothing more to prove on your side.

Do you have an ISP router in front of the OPNsense? Do you have one of their routers that previously worked (especially for IPv6)? They may expect to see the solicit on a specific MAC address and spoofing that can help, but as I said there could be a number of reasons why you do not receive a reply and none are under your control.


Cheers,
Franco

[karvec]

No ISP provided equipment, just ISP <-> MB8600 cable modem <-> OPNsense box <-> various switches, APs, etc.  Since I am really just troubleshooting the ISP <-> OPNsense I haven't focused on any of the LAN side of things...  Figure when I get it working OPNsense <-> WAN I should be golden.

I believe it has worked in the past but I wasn't very interested in learning IPv6 then, or setting it up.  I should have taken advantage of the learning experience when the opportunity was there, since it seems like it no longer is.

Thanks for your time and responses.  If I manage to change something and it does start magically working I will definitely post my fix to this thread.

karvec

[franco]

Thanks for the follow up. Yes, making the WAN side work should bring it back for the clients too. Good luck.


Cheers,
Franco