> Even though it may be easy to make end systems and local > LANs v6 capable, rest, the center part, of the Internet > keep causing problems.
Really? My impression is that it's very much the edge that's hard - CE routers, and in particular cheap, nasty, residential DSL and cable CE routers. Lots of existing kit out there that can't do v6, and the business case for a fork-lift upgrade just doesn't stack up. It's a cost issue, though, not a technology one - it's perfectly possible to deliver v6 over these technologies. Tunnelling, while not ideal, is certainly a workable stop-gap, and I'm *very* happy to have real, globally uniquely addressed end-to-end Internet in my house again as a result. Systems can be a problem too - both in convincing IS people to change things, in getting the budget for changes, and in finding all the dark places hidden in the organisation where v4 assumptions are made. But in the Internet core? I don't see any huge obstacles at $ISP_DAYJOB, with any of the people I know in the industry, or with the ISPs I do business with. For co-lo, VPS, leased lines, real Ethernet tails, v6 connectivity is being delivered and working fine today. Regards, Tim.