Why is ipv6 stalling?

Every now and then I end up asking myself why IPv6 still feels like a thing that is always coming instead of a thing that fully arrived. At this point the protocol is not new, the address exhaustion story is old, and everybody in infrastructure knows the argument. But knowing the argument and feeling the pressure to move are two different things.

A lot of the stall is probably just that IPv4 kept working longer than it deserved to. NAT is ugly, private address space is a patch, and whole layers of modern networking are built around compensating for that mess. But it works well enough. Most teams do not wake up in the morning thinking about the elegance of address allocation. They think about whether the application is reachable, whether the VPN is up, whether the load balancer is healthy, and whether users are complaining.

I was watching this video and it landed on the same feeling for me. The technical case has been obvious for a long time. The part that keeps dragging is everything around the protocol.

So the stall makes sense to me, even if it is a little depressing. IPv6 is better. The internet would probably be cleaner if we had all moved properly years ago. But transitions only happen when the pain of staying put becomes worse than the pain of changing, and for a lot of people IPv4 still has just enough life left in it to delay that moment.