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Description of problem:
Every since upgrading to FC3 (from FC2) the web has been extremely
slow.  It took me forever to track down the problem, but I'm sure this
is it:

The gist of the problem is the (new?) bind in FC3 tries to resolve a
lookup using ipv6 first USING ALL resolv.conf search domains, and only
then tries ipv4.

Here's my resolv.conf

search mydomain.com region.myisp.com myisp.com
nameserver 127.0.0.1

Note: myisp.com seems to be very slow. To recreate this bug, try using
a very slow far away (or even bogus?) nameserver for the last search
domain.

Now I do:
tcpdump -i lo

then:
lynx http://redhat.com

tcpdump (edited for brevity) shows me the resolver is trying:
07:33:28.886360 IP AAAA? www.redhat.com. (32)
07:33:28.887045 IP AAAA? www.redhat.com.mydomain.com. (46)
07:33:28.911696 IP AAAA? www.redhat.com.region.myisp.com. (49)
07:33:28.912407 IP AAAA? www.redhat.com.myisp.com. (46)
07:33:33.912145 IP AAAA? www.redhat.com.myisp.com. (46)
07:33:38.912194 IP A? www.redhat.com. (32)
07:33:38.912700 IP A www.redhat.com (102)

Note how it takes 10 seconds to try all the ipv6 AAAA queries before
trying the one A query that succeeds.

I have tried turning off as much ipv6 as I can on my system
(/etc/sysconfig/network: IPV6*=no).  I am not using ipv6 and my isp is
not using ipv6.

I did find a usenet post saying passing -4 to named may help disable
ipv6, but that option is only available in bind>=9.3 and FC3 is 9.2.x.

I can prove the above is the cause of the 10+ second delays for
lookups by removing the isp (or all) search domains.  Then my lookups
are very fast.  Yet even then tcpdump shows me it is doing a lookup on
the (at least) 2 AAAA records first.  That means extra net (albeit lo)
traffic for no reason.

If someone uses search domains, especially ones outside their network,
and a local caching name server, they will hit this problem and not
know why everything is crawling.

I think the resolver should try ipv4 FIRST, OR try ipv6 on the domain,
then ipv4 on the domain and only then try the search domains.


Version-Release number of selected component (if applicable):
bind-9.2.4-2

How reproducible:
Always

Steps to Reproduce:
1. run a local caching name server
2. add some slow domains to your search line in /etc/resolv.conf
3. use a client (NOT host and dig) to hit a remote address causing a
lookup
    

Actual Results:  5 to 15 second delay before the client responds.

Expected Results:  0 to 2 second delay before the client responds.

Additional info: