In my experience, the biggest hurdle to installing a pure IPv6 has nothing to do with network gear or network engineers. That stuff I expect to support v6. This biggest hurdle is the dumb stuff like machinery interfaces, surveillance devices, the must have IP interface on such and such of an obsolete appliance, etc. The dumb legacy app that supports the ancient obsolete pen plotter that we must keep forever, etc.
The next largest hurdle is trying to explain to your server guys that you are going to go with all dynamically assigned addressing now and explaining to your system admin that can’t get a net mask in v4 figured out, how to configure their systems for IPv6. There are a lot of people in the IT industry who are not nearly ready for v6. In large enterprise networks, there is lots of East/West communications between systems and that is very difficult to transition through a dual stack process without tripping over a bug or serious incident. It is really hard to look at cost difference in v6/v4 but there will be a definite learning curve with the associate oops moments and re-education that all costs time/money/downtime. The simply reality is that there are more IT people that understand v4 and do not understand v6 yet. Steven Naslund Chicago IL >I'd strongly disagree that it anywhere near doubles costs. Ultimately you're >buying hardware X and it's going to cost whatever it costs. So what more do >you really need to do to support IPv6? >Well, let's say you're using OSPF. >This means you'll also need to use OSPFv3, but that's not hard because your >OSPFv3 configs are going to basically mirror your OSPF configs. You'll need to >>run IPv6 over iBGP, perhaps, and over eBGP to your peers and transits, but >that's just another set of addresses bound to interfaces, sessions that mirror >the IPv4 ones, and policy rules/filters. If >you're doing super heavy TE, then >the filter configs might take some effort, but if we're talking about smaller >shops, doing heavy TE is unlikely. At that point, you just add a v6 address to >your >layer3 interfaces and you're good to go for the network side. >Most of the time you spend configuring things won't be v4 or v6 specific, and >the v4 specific configurations can be copy/pasted with a quick string swap to >support v6 in a lot of cases.
