> for the last 2-3 weeks I've noticed (it could have been going on longer) that
> I seem to be preferencing IPv6 DNS AAAA returns over A, for my pkgsrc FETCH_CMD
> default, in web browses, shell commands.
> 
> I don't want to disable IPv6. But I do need some finer grained method to control
> in user-space if A preferences AAAA or vice-versa.
> 
> I'm on both 6bone and 2001: space, and I have to say that the reachability
> and RTT for some very significant nodes (like ftp.mozilla.org) is not tenable
> for me to preference V6 right now, or when offsite and depending on other peoples
> V6 tunnels.
> 
> I've done a brief search in email, but I can't see anybody else having similar
> problems, or a well known FM to read, that explains how to use something like
> nsswitch.conf to direct if I want A or AAAA.

	are you using BIND 9.2.x?  BIND 9.2 series makes A6 queries in addition
	to necessary AAAA + A queries, so the performance sucks.  slow
	deployment of EDNS0 also contribute (negatively) to your query
	performance, as eery time you hint non-EDNS0-capable nameserver
	you have to retry.

	other problems are described in morishita/jinmei draft (common
	misbehavior of nameserver on AAAA query).

itojun