Sorry to hear about your DNS server issues.
I had to give up on our DNS servers long ago because they can’t keep the DNS servers working much of the time.
Things aren’t getting better becuase now not every machine is even being defined in our DNS server which is a head scratcher to me but security is starting to take a stance you should now the machine exists so my nslookups no longer even find servers on our in-house network.
Sounds like I might be getting some hidden benifit as well when cloverleaf might want to force me to use our unreliable DNS servers.
Ideally hard coding of IPs seems like the poorer choice but our reality has shown it to be the more robust and maintanable choice.
So don’t dispair, we are proof that life goes on with hard coded IPs.
However, we do use the /etc/hosts file sometimes and depend on it being looked at first so now that is a bit of a question mark, too.
Having said that, what you described brought to mind a related problem I had with getting my xterms to launch because I use was using the hostname of my cloverleaf servers to launch the xterm logins, which weren’t getting resolved.
As Charlie already pointed out the /etc/*.conf files can play a role and Charlie’s comment is what triggered my memory for this reply.
In my case the network group had added 2 new domains and not told anyone.
I finally resolved the problem by adding a search entery into my /etc/resolv.conf file so the 2 new domains could be resolved.
Here is what is currently in my /etc/resolv.conf file:
nameserver 143.111.64.254
nameserver 143.111.89.254
nameserver 143.111.201.254
search mdacc.tmc.edu utmdacc.org mdanderson.edu
Russ Ross
RussRoss318@gmail.com