Re: lib/42405: libc: getaddrinfo() should perform T_A lookups before T_AAAA lookups, was: Resolver problems

[Jason Thorpe <thorpej%shagadelic.org@localhost>]

On Dec 4, 2009, at 6:01 AM, Matthias Scheler wrote:

> On Fri, Dec 04, 2009 at 08:25:29AM -0500, Greg Troxel wrote:
>> As for the problems, are they the result of a host getting a non-working
>> v6 address on a broken subnet?
> 
> No, the problem is caused by a router whose builtin caching nameserver
> sends broken replies if NetBSD's libc queries for AAAA records. The broken
> answer gets ignored and NetBSD's libc waits 15(?) seconds before trying
> to query for A records.

Maybe we should ask for AAAA and A in parallel.  It would also be nice if all 
of this was transparent to libc.  IMO, all resolving activity should be done 
through mdnsd, and we can make policy tweaks there.  Plus you gain system-wide 
caching so that multiple apps don't have to suffer the broken behavior (one one 
app suffers, everyone else querying for that address gets the cached correct 
response).

> 
>       Kind regards
> 
> -- 
> Matthias Scheler                                  http://zhadum.org.uk/

-- thorpej