IPv6 is a perfectly fine protocol. Supporting IPv6 is absolutely nothing like "ripping out your spinal cord and putting a new one in". It's largely trivial if

IPv6 is a perfectly fine protocol. Supporting IPv6 is absolutely nothing like "ripping out your spinal cord and putting a new one in". It's largely trivial if you aren't doing anything tricky--and, notably, it requires nothing that an IPv4.1 wouldn't require. The Berkeley socket API was designed with support for multiple protocols from the start, so you shouldn't have to touch much beside your address structures and name resolution code. And I say this from the standpoint of someone who added DHCPv6 support to a DHCPv4 server, which actually is tricky, since DHCPv6 is an entirely different protocol from DHCPv4 and substantially more complicated to boot. It still wasn't all that bad. Most importantly, IPv6 is done. It's been done for years now. The router support is there. The OS support is there, with the exception of some laggards who really should get around to implementing DHCPv6. It's in active use. (Do you have a DOCSIS 3.0 cable modem? Congratulations, you're using IPv6!) The biggest obstacle to deploying IPv6 is just doing it, and again that's not going to be any easier with an IPv4.1.