On 3/5/2010 06:38, Cameron Byrne wrote:
There is one of other catch with NAT64 and IPv6-only. It breaks communications with IPv4 literals. Now, you might says that IPv4 literals in URLs are very seldom.... well ... have a look at how Akamai does a lot of their streaming. I just hope it does not come to a show-down where networks move to IPv6-only since IPv4 is a goner and now Akamai content is not available while IPv6 early adopters like Google and Limelight laugh all the way to bank.
One of the reasons I like the idea of DS-Lite. It may not be as native-IPv6 pure-and-holy as NAT64/DNS64, but it allows end users, IPv4 only applications, and legacy/non-IPv6 equipment to actually use IPv4 addresses. When the end user's favorite application stops working, or he can't play games online with his Xbox 360, he won't care about any explanations of NAT64/DNS64, or whose fault it is. He'll just want things to work. DS-Lite still allows this, and doesn't have any real impact on IPv4 exhaustion, since the end user will be issued RFC1918s, (likely) overlapped with other end users' RFC1918s. I also speculate that if one takes a large user community, say, customers of an ISP, and put them on NAT64/DNS64, we'll likely discover a lot more "IPv4 only" applications/services/appliances out there than we were expecting via the explosive ringing of flooded help desk lines. :p Granted, DS approaches will slow native IPv6 adoption a bit, but I think the real-world alternative is chaos. I personally prefer a scenario where users can go on using the internet as they've always done, likely oblivious to whether any particular site or application is using IPv6 or IPv4, while "behind the curtain" these same sites/applications are switching over to native IPv6, than a scenario where things simply stop working for them. Also, I hope that any pain associated with going through a CGN used in any of these sorts of approaches, and/or the benefits of native IPv6, will speed native IPv6 adoption more than any transition method might slow it. One can hope. :p