WWW/DNS problems

Ryan O`Connell nemesis at eh.org
Tue Aug 17 15:31:41 UTC 1999


Not strictly a North American problem but I was wondering if anyone had seen
this behaviour.

We currently have two blocks of IP address space, 195.224.206/24 and
193.193.186/23. Everything works fine from 195.224.206 but from 193.193.186
there are often problems accessing web servers - either they don't respond for
ages then are suddenly OK, send just the headers in response to a GET request
then stop or just plain don't respond to HTTP queries at all. This appears to
happen mostly with Netscape servers although I only have a few examples so far
so I'm not sure. (www.real.com, www.cisco.com, www.etrade.com, www.bt.com)

We also have two lines out of the building, although I've tried routing in
various ways and the problem seems to follow the IP address rather than the
outbound line. (IP addresses are, for the moment, tied to the line until we
get BGP on the line currently serving 195.224.206/24 however I can't see how
this could be an inbound line problem.)

I believe this to be a DNS problem as I can't see anything else that could be
causing a problem - it doesn't seem to matter what web browser is used (IE,
Netscape, Lynx or even telnet) or if a web cache (Squid) is used or not.
There are three reverse DNS servers in totally different locations (One on our
site, one on the UK Joint Academic Network and one in Switzerland) so I don't
think part of the net being unreacable from somewhere can be the problem.

The only *POSSIBLE* explanation I can come up with is that the IPv6 AAAA
entries for 193.in-addr.arpa are confusing some nameservers and causing this
problem. I'm really grasping at straws though - does anyone have even the
slightest idea what cound be going on? (Even off-list wild-guess suggestions
would be appreciated.)


Ryan O'Connell - http://complicity.olf.co.uk:8080/ - <nemesis at eh.org>

How do you sleep? How do you last the night and keep the dogs at bay?
How do you feel when you close your eyes, and try and drift away?
Does it feel any better now? Does it mean anymore
When the angel of death comes knock, knocking, And banging at your door?

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