Why is ipv6 stalling?

People often ask why IPv6 still feels perpetually unfinished. The answer is simpler than it seems.

IPv6 adoption depends on two things: the pain of IPv4 and the cost of switching.

Most discussions focus on the first number. IPv4 ran out of addresses years ago. NAT is a workaround, private address space is a workaround, carrier grade NAT is a workaround for the workaround.

From a protocol design perspective, IPv6 is clearly cleaner.

But the second number is the one that matters.

The cost of switching. It involves more than just replacing routers. It is touching firewalls, load balancers, monitoring systems, VPNs, applications, documentation, operational habits, and every engineer who has learned to think in IPv4. A network can be technically capable of IPv6 and still be expensive to operate in dual-stack mode.

This is why IPv6 feels stalled even though everyone knows the argument. Most infrastructure teams are not rewarded for protocol elegance. They are rewarded for uptime. If IPv4 continues to keep services reachable, users happy, and incidents rare, the incentive to migrate remains weak.

I was reminded of this while watching a talk about IPv6 adoption. The interesting part was not the protocol itself. The interesting part was that the technical debate has largely been over for years. What remains is an economic and organizational problem.

That suggests a useful way to think about the transition.

A technology does not replace another technology because it is better. It replaces it when the cost of staying with the old one becomes greater than the cost of adopting the new one.

IPv6 is waiting for that inequality to flip.