Posted by Aaronmacaron 1 day ago
What's going on in Spain?
like say
* https://1.1.1.1/cdn-cgi/trace
vs
* https://one.one.one.one/cdn-cgi/trace
When ipv6 threads like this come up, someone eventually mentions T-Mobile is completely IPv6 now but they must have IPv4 tunnels because I have IPv4 turned off on my modem/router and can still visit both those URLS
Basically to reach any v4-only resource you need a translator, typically NAT64. This maps the entirety of the v4 internet into a /96 of IPv6 space (last 32 bits).
DNS64 is one way to access this, which will return a result for 'amazon.com' like:
A = `98.87.170.74` AAAA = `64:ff9b::6257:aa4a`
Combining this with CLAT lets you punch in an IPv4 literal like 1.1.1.1 and your phone/computer will do this conversion from v4 -> v6 locally without you changing anything. So 1.1.1.1 would become `64:ff9b::101:101` on-device - and that's actually what your mobile ISP sees.
T-Mobile and most mobile operators use 464XLAT - which has been in Android & iOS for at least 8-10 years now if memory serves.
It lets you visit 1.1.1.1 because your phone is converting it automatically to T-Mobile's NAT64 prefix (CLAT - customer side), it traverses their network v6-only, and then it ends up at their translator (PLAT - provider side) and becomes normal NAT'ed v4 traffic out to CloudFlare.
Generally: I'm really surprised that Norway is just at 27%. I think I've been with 3 different residential ISPs the last 15 years, and all of them have done IPv6 perfectly well (two nits: I think one required a trivial opt-in, and my current ISP is just giving me /60 which isn't perfect).
Edit: Oops, sorry to my current ISP for shaming them. Some googling told me that one can get a /56 using DHCPv6-PD. I'll try that!
ARIN was gonna charge me $100 to authenticate and recover the account, but once I asserted and notarized my letter of relinquishment, the process went real quick!
Was fun seeing IPv6 running for a few days without problems.
Chris Siebenmann has written extensively on IPv6: https://utcc.utoronto.ca/~cks/space/?search=ipv6
Google has some weird way of asserting connectivity, and I suspect that when connectivity on one protocol is lost, it is impossible to maintain or establish connectivity through the other one (IPv6) even if it is available upstream.
I am rather infuriated with the status quo at this point, because it is impossible to disable IPv6 on my devices and it is also impossible for my ISP to disable IPv6 on my LAN or on the CPE router which they own and control.
Due to chronic WiFi issues I was eventually forced to place my ISP router into Bridge mode permanently, and I use a 3rd party Netgear which I own, and does not have the same WiFi issues, and where IPv6 is optional (and often fails, because its implementation is buggy and glitchy for no reason.)
I recently purchased a brand-new LaserJet printer, and since it needs nothing to do with the Internet or a WAN outside my home, I thought it'd be great to simply disable IPv4 and stop doing the DHCP dance.
Well it immediately fell off the net completely. I couldn't figure out how to expose its IPv6 address or contact its management interface.
Hypothetically, Bonjour and mDNS should make this a no-brainer. Hypothetically, disabling IPv4 shouldn't even prevent it from connecting to the Internet. But I was ultimately forced to factory-reset it.
IPv6-only LAN makes a lot of sense for most people, and perhaps reduces attack surface a little. If you have the means, I highly recommend setting it up!