"IPv6 is a 1990s solution to a 1980s problem, designed by committee before we fully understood how the internet would evolve. It solves address exhaustion, but creates more problems than it fixes — and doesn't align with how modern networks actually work."
IPv6 was designed under the assumption that:
NAT was bad
Every device should be globally addressable
Hierarchical routing and massive address spaces were the future
NAT enabled firewalls, local network segmentation, and privacy — it's now a feature, not a bug.
Global addressing is a security liability, not a benefit. Nobody wants their fridge on the public internet.
Most real-world networks are flat, dynamic, and heavily virtualized, not rigidly hierarchical.Should be globally addressable, not so much: IPv6 explicitly includes site-local and link-local addressing. A fridge ought to ask for a site-local address, not a global one.
The core of IPv6's addressing is that if you make the address space large for everyone, even the use cases that don't need it, you get rid of many minor headaches later. Like the sort-of-colleague I have who suddenly needed access to some 186.168 servers from a distant network that also happened to use 192.168, partly overlapping.