On Wed, 16 Jan 2008, Mark Andrews wrote: > > Since when has Informational been equivalent to Standard? Since (a) there is no standards-track specification to override it, and (b) all implementations follow RFC 3974, and (c) it's the obvious extension of v4 behaviour to v6. I should have said in my previous message that not only do the most popular MTAs fall back to AAAA, but BIND also includes AAAA in the additional section of MX replies, which re-inforces the RFC 3974 interpretation. > Do you really thing we should be trying to force a upgrade > of all MTA's on the planet to support MX synthesis from > AAAA when there is no engineering need to to this? They have already been upgraded in this way. Even without fallback-to- AAAA, they have to be upgraded to handle IPv6 anyway, because the IPv4 MX lookup algorithm breaks as I described in http://www1.ietf.org/mail-archive/web/ietf/current/msg49843.html > MX from A was a transition strategy. It might have been intended that way, but it has become a permanent part of the protocol. Tony. -- f.a.n.finch <dot@xxxxxxxx> http://dotat.at/ WEST FAIR ISLE FAEROES: NORTHEASTERLY VEERING SOUTHEASTERLY 5 TO 7, PERHAPS GALE 8 LATER. VERY ROUGH. SHOWERS. MAINLY GOOD. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf