[CentOS] DNS lookup delay with centos & postfix

Wed Jul 25 22:23:21 UTC 2012
Steve Lindemann <steve at marmot.org>

On 7/25/2012 3:55 PM, John R Pierce wrote:
> On 07/25/12 1:57 PM, Steve Lindemann wrote:
>> 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.
> DNS lookups default to using 53/udp, and only use 53/tcp for zone
> transfers.  could it be 53/udp is being lost/blocked between this host
> and your ns1 ?

good question but unlikely... all the servers are in the same dmz and 
sit on the same switch.