slow dns resolutions

[Matthew Seaman]

On Sun, Mar 07, 2004 at 08:57:28AM -0500, Dragoncrest wrote:

> Resolv.conf has the right dns servers in the right order and my hosts
> file is perty much bare, save for the names of both machines at my desk,
> so I'm stumped as to what could be causing this.  Can anyone suggest
> anything?

I've seen very similar symptoms occur when the FreeBSD box is
attempting to do IPv6 AAAA lookups, the way the standards say
getaddrinfo(3) should operate nowadays.

Windows, typically, completely ignores the existence of IPv6, and
unfortunately many suppliers of advertizing (it always seems to be the
advertizers -- I've never had any problem with other web content
providers) on the net still haven't woken up to the fact that there is
more to life, and computing, than just the latest outpourings of
Redmond.  Anyone would think they don't want you to see their
adverts...

It's not as if they haven't had enough time to implement any IPv6
support either: the first IPv6 RFCs were published 10 years ago.  Not
only that, but they are running DNS software that is willfully broken
even by pre-IPv6 standards: when presented with a request for a RR
type that the server doesn't recognise, it is meant to reply with a
NXDOMAIN error code.  These just sit there dumbly, forcing the client
side to wait for the whole 30s of the DNS timeout.

Solutions: you can rip all of the IPv6 support out of your FreeBSD
system -- which involves editing your make.conf and kernel config and
doing a full builworld cycle.  Or you can run your own web proxy which
filters out the advertizing: the www/junkbuster port is one such, and
there are several more available.  Or you can do like I do, which is
to run your own recursive DNS server, but load it with some dummy
copies of the advertisers' domains.  Nb. if you do either of these
last two, be aware that you can hurt financially those often very
useful and otherwise blameless sites that carry the advertising.

	Cheers,

	Matthew	

-- 
Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20040307/36a2eb3f/attachment.bin