Given the time between IPv6 design and the eventual global adoption of it and abandonment of IPv4, will the broader adoption of IPv6 reveal problems addressed in a future revision?
I'll admit to being willfully ignorant of IPv6 other than seeing it as enormously more complicated than IPv4, trying to solve too many problems at once. I sometimes wonder if maybe IPv6 didn't appear so complicated and different that adoption might have been increased.
Couldn't they just have added a couple of extra bytes to IPv4 to come up with something that worked like IPv4? I also wonder about an addressing scheme like IPX, where a single network address covers an entire broadcast domain and node addresses are MAC addresses plus the network address. IPX network addresses were only 8 bytes, maybe that wouldn't be future proof enough (4.2 billion networks). I'm not talking about IPX as a protocol, just the system for addressing.
The advantage is relative simplicity (no need for DHCP, network addresses are discovered and the rest is built-in), broadcast domains can scale arbitrarily large without needing to renumber -- sure you can start out every network with a /16, but often they don't and there are complications in organizations just arbitrarily shifting masks past /24, such as running into other networks in the local routing domain.
Since node addresses are locally determined, ISPs would need to only assign a network address which would allow for basically unlimited public network addresses to each subscriber.