On Feb 17, 2011, at 9:44 04AM, John Curran wrote:
On Feb 17, 2011, at 9:32 AM, Valdis.Kletnieks@vt.edu wrote:
On Thu, 17 Feb 2011 08:08:50 EST, John Curran said:
Rather than saying 240/4 is unusable for another three years, perhaps the service provider community could make plain that this space needs to be made usable
In other words, you're going to tell Granny she needs to upgrade to Windows 8 and/or replace her CPE because you couldn't get your act together and deploy IPv6 - even though her friends at the bridge club who are customers of your clued competitor didn't have to do a thing.
Not, what I'm saying is that we've been considering this matter for more than 10 years, and as old as her machine is, it would have been patched once since then if we had bothered to note that "Reserved for Future Use" should be treated as unicast space.
The same argument applies now: unless there is a reason to save 240/8, it should at least be redefined to be usable in some manner so that we don't repeat the same argument 5 years from now.
John, my usual rule of thumb for something like this is 8-10 years -- 3-5 years for the next major version of Windows, plus (at least) 5 for enough old machines to die off. There are just too many machines that don't listen to Windows Upgrade; you can't roll out a major change that way. We won't even talk about things like home NATs and cable/DSL/fiber modems, which tend to be longer-lived. If we'd started this 10 years ago, as you suggest in a later note, maybe it would be present in Windows 7, possibly even Vista. So we'd be set -- Windows XP is gone by now, right? Oh, yeah, it isn't... And as Valdis points out, it just doesn't buy us that much time. It might be worth doing for ISP backbones, and for things like tunnel endpoints. For anything else, it's not worth the effort -- and I suspect never was. --Steve Bellovin, http://www.cs.columbia.edu/~smb