Re: I'll take my best shot
I WAS a network engineer and casting my eye over that I couldn't find much to fault it.
It bears a little amplification.
firstly it is a new network. to use it fully requires that every link in between be fully V6 or able to tunnel it. I think.
Secondly NAT will not go away. NAT is here, works, already implemented, and has many advantages for e.g. dumb consumers, and indeed corporates who can spend the time making it work right, insofar as its detractors consider that statement has any meaning.
Thirdly, it will take years to deploy. legacy kit will still be there in IPV4 in 20 years time, I am sure.
The problem is it doesn't actually offer any advantages I can see that mean you will rush to deploy it if you have V4 addresses already. I actually envisage that many organisations will deploy it internally long before they get rid of some NAT that turns it onto a V4 for tunnelling across the internet.
Finally, security and anonymity are looking to be bigger issues than running out of net numbers these days. so even if IP stays, what are the odds that some kind of other protocol replaces UDP/TCP to add some measure of man in the middle security and indeed, given the endless argument about who pays for the internet, what are the odds that some kind of 'chargeable packet' field isn't added somewhere. Imagine a field that increments every time it passes a node, representing the cost of getting that packet across a given route.
Back in the day, every year was going to be 'the year of Unix' . Well there never was a year of Unix, but ever since I first heard that phrase, one by one alternative operating systems have withered and died, until. we pretty much have Unix or Linux running most things apart from custom hardware with real time needs, and Microsoft.
Novell netware, NET BEUI, token ring, X-25 - X-400 none of these have vanished altogether: the key is you don't deploy them in new systems.
Some version of IPV6 will probably carry us through the next 30 years, but there will never be a year of IPV6 either.
Just slow steady incremental growth where it makes sense, once its as stable and reliable as V4 is.
Id like someone to comment on how big a BGP routing table has to be with IPv6 as well.