Does dig use libresolv or read directly from resolv.conf? Also do you have a timeout configured in resolv.conf or are you relying on the os default? On 25 Jul 2012, at 21:57, Steve Lindemann <steve at marmot.org> wrote: > I'm a bit baffled by this and I'm looking for ideas... > > background: > two DNS servers (ns1 & ns2)(64bit CentOS 5.8) > one email server (64bit CentOS 5.8 & postfix 2.3.3) > one nagios server (64bit CentOS 5.8 & nagios 3.3.1) > > situation: > - all servers configured to use both DNS servers for lookups > - ns1 server down for hardware problem > - nagios alerts that smtp on email server taking longer than 2 seconds > to respond > - nagios alert for smtp on email server clears when ns1 returns to service > > - when I use dig from the email server command line there is no problem > or delay when ns1 is offline. It worked without a hitch using ns2. > > Anyone have any ideas for why nagios would have trouble testing smtp on > the email server when the primary dns goes offline? I'm not even sure > where to look or who else would make sense to ask the question of on > this one. I'd appreciate any insight anyone out there has on this. > -- > Steve > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos