On Tue, 27 Sep 2011, Alfred von Campe wrote:
Most of my desktops are still running CentOS5, but I have installed CentOS6 on a few of them. The users on those desktops are reporting that DNS lookups are slow, and from my brief tests, that does appear to be the case. After some googling, I found a suggestion to disable IPv6, but that didn't help. So I tried to figure out where the delay occurs using strace and ltrace, but that didn't help much. When running ltrace, the process I'm trying to trace (host, nslookup) just dies. And the output of strace does show a 3+ second delay, but I can't figure out what it's telling me:
The CentOS5 systems on the same network with the same /etc/resolv.conf file do not have these delays. Has anyone else seen this or have some suggestions as to how to debug this?
You probably want to do an strace -f host blah rather than a basic strace, or I think you'll lose what's going on.
Are you running either sssd or nscd on your box?
I've done nothing special, and DNS seems fast enough.
jh