Comment by cyberax

Well, yes. Except that AC came to dominance much faster than IPv6, the AC/DC war lasted less than 10 years, with the AC quickly coming to domination. Because AC provides a clear performance advantage over DC.

This is not really true of IPv6. It _still_ has tons of actual operational issues, and in the best case, it does not provide any tangible improvements over IPv4+NAT for the vast majority of users.

For example, in-flight entertainment works by assigning you an IPv4 address and allowlisting it in the gateway rules. This does not work with IPv6 because of privacy addresses and SLAAC. You might think that you just need to do stateful DHCPv6, but Android doesn't support it. Heck, even simple DHCPv6 PD automatic configuration is _still_ not a standard ( https://datatracker.ietf.org/doc/rfc9762/ )!

So to this day, some of the most visited sites like amazon.com, ebay.com, tiktok.com, slack.com or even github.com do not support IPv6. I also keep providing this example, year after year: there are no public VoIP SIP providers in the US that simply _support_ IPv6. Go on, try to find one.