[Dnsmasq-discuss] dnsmasq giving timeouts

[Davide Ferrari]

Hi

I'm using 

Dnsmasq version 2.45  Copyright (C) 2000-2008 Simon Kelley
Compile time options IPv6 GNU-getopt no-ISC-leasefile DBus I18N TFTP

(from Debian Etch) and starting a couple of days ago dnsmasq responds from 
time to time with a timeout to dns requests.

Let me explain:
- host $A has dnsmasq running
- host $B has host $A in resolv.conf
- host $C is another host with $A in resolv.conf

when from host $B I do a

# ping $C

the ping works but, from time to time, it waits up to 5 seconds before 
responding. But no ping is lost, it seems that is only waiting for DNS 
resolution *before* sending the actual ICMP packet.
Same way with dig. From $B I do

# dig @$A A $C

and sometimes it waits up to 5 seconds again, then gives the correct answer 
with a query time of a few milliseconds!

stracing the dnsmasq process doesn't show anything strange, and looking with 
tcpdump at the outgoing DNS traffic from the dnsmasq host, the strangest 
things are lots of AAAA requests that seems like what's happening in this 
thread

http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2005q2/000221.html

but as you can see I *do* have IPv6 enabled in dnsmasq (and Debian Etch), 
although I'm on a IPv4-only internal network.

The only thing changed lately was the SOA/NS (we are switching ISP) for our 
public zone (which we are masquerading internally with dnsmasq). The new ISP 
does have an AAAA record for one of its name servers.

Any idea?

Thanks in advance

-- 
Davide Ferrari
Atrapalo.com System Administrator