I think I have a problem with DNS lookups on 127.0.0.1. Currently a number of programs (openoffice, gedit, gkrellm and others) hang for a long time when running and all hang on the following code:

connect(19, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("62.30.112.39")}, 28) = 0
send(19, "\257\3\1\0\0\1\0\0\0\0\0\0\tlocalhost\0\0\1\0\1", 27, 0) = 27
gettimeofday({1090270763, 754230}, NULL) = 0
poll([{fd=19, events=POLLIN, revents=POLLIN}], 1, 5000) = 1
ioctl(19, FIONREAD, [43]) = 0
recvfrom(19, "\257\3\201\200\0\1\0\1\0\0\0\0\tlocalhost\0\0\1\0\1\300"..., 1024, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("62.30.112.39")}, [16]) = 43
close(19) = 0
time(NULL) = 1090270763
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 19
fcntl64(19, F_SETFD, FD_CLOEXEC) = 0
setsockopt(19, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(19, SOL_TCP, TCP_NODELAY, [1], 4) = 0
connect(19, {sa_family=AF_INET, sin_port=htons(631), sin_addr=inet_addr("127.0.0.1")}, 16

You can see from the trace above that it is doing something on 62.30.112.39, which is specified in my resolv.conf file, and then also on localhost, which is not. This problem has been made better by minimising the timeouts on DNS lookups but I would like to stop this completely.

I have read on the following site http://www.jw-stumpel.nl/leakage.html that ipv6 can cause 'leakage' and lookups to be performed on my localhost address. Does anyone know how to stop this?

I had this problem with a recent SuSE install. For some reason SuSE had IPv6 turned on as standard and my lookups took a hell of a time because it first tried DNS lookup thrue IPv6.

After some tries I managed to turn IPv6 off. I think I did it by adding the line
to the file /etc/modprobe.conf.local. If you don't have that file in your distribution you could probably put the line at the end of /etc/modprobe.conf.

I'm happy to hear if this solves your problem.

Regards,

Jens

PS. There are a lot of old threads dealing with similar problems here at LinuxQuestions, so if this doesn't help I suggest you do a search and try some of the other solutions. DS.