Except that A6/DNAME also supported your upstream being able to initiate prefix renumbering without having to involve the end customer... As I understand it: foo.blah.org. IN A6 MYISP1 ::4321:53ef MYSIP1 IN DNAME 10 prefix1.isp1.net. ::dead:beef:: Then, in ISP1's isp1.net zone file prefix1 IN DNAME 100 feed:beef:: This way, if ISP1 needed to renumber for some reason (turning in old /32 in trade for /30, for example), they could go through the following steps: prefix1 IN DNAME 200 feed:beef:: prefix1 IN DNAME 100 2314:5124:: Wait a few days for everyone to catch on to the new DNAME, then, prefix1 IN DNAME 100 2314:5124:: Voila, painless ISP renumber without substantial end-user headache. Sure, there are other issues (like bone-headed ACLs that accept/deny host based on 128 bit address), but, this at least solved part of that problem. Owen --On Sunday, November 28, 2004 8:51 PM +0200 Pekka Savola <pekkas@netcore.fi> wrote:
On Sun, 28 Nov 2004, Paul Vixie wrote:
the property of a6/dname that wasn't widely understood was its intrinsic multihoming support. the idea was that you could go from N upstreams to N+1 (or N-1) merely by adding/deleting DNAME RRs. so if you wanted to switch from ISP1 to ISP2 you'd start by adding a connection to ISP2, then add a DNAME for ISP2, then delete the DNAME for ISP1, then disconnect ISP1.
the DNAME was expected to be inside your own zone. presto, no lock-in. my theory at the time, bitter and twisted i admit, was that we had too many ISP employees in positions of power inside IETF, and that A6/DNAME was seen as shifting too much power to the endsystems. i've since learned that it was just another case of FID (fear, ignorance, and doubt). [...]
Isn't about the same achievable with about two or three lines of scripting (or a new zone parsing option for bind ;) with a lot less protocol complexity?
As you note, A6/DNAME wasn't a panacea. A lot additional stuff is needed to achieve the goal. It seems to me that actually the A6/DNAME part is a relatively simple one to achieve using current mechanisms.
-- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
-- If it wasn't crypto-signed, it probably didn't come from me.