UNIX for Advanced & Expert Users

all of the above - and you can as well add the option
options rotate
into your /etc/resolv.conf - which enables your box to use all nameservers, not just the first.

Thanks all for answering. I still do not understand why impact is observed when the secondary is down and the primary is still up.

The "norma"l approach for a root-cause analysis is to turn on verbose syslog logging for your DNS daemon processes and review the log files for errors and anomalies.

Did you mention your OS and what version of named (or whatever DNS daemon process) you are running, and your current logging configuration for this process?

Sorry, if I missed it.... please post "the details' again. Thanks.

DNS servers are Windows 12. I do not have much control over those. Is there anyway to increase the verbosity of logging in AIX client?

The AIX clients are running AIX 6.x , as far as I remember. To me it's a puzzle that the services are impacted when the 2nd server in /etc/resolv.conf file goes down. I have not tested what happens if the first one goes down and the 2nd one remains up.

THANKS

Actually, if the 2nd nameserver in /etc/resolv.conf goes down, there is no impact at all, unless there is options rotate.

are we sure the first one works / is accessible from the host. I agree with MadeInGermany there should be no need to ever go to the second if the first works fine. You could switch on options debug to see whats really wrong.