Let me preface this by saying that I do not actually believe I have a DNS
problem, but I wish to asker wiser heads than mine if that assumption is
correct:


I've started having real problems in the last month with DNS names that are
only resolved internally by my DNS server.
The problem is sporadic.
Publically-resolved names get resolved without issue.

The system has been in play for over 10 years, originally as a 5.1 server
and currently as NW6.
I moved the system to new hardware about 3 months ago.
I used Portlock's Storage Manager to image the server from one piece of
hardware to the other, however, so I don't think the change of hardware
would be an issue.

OS: NW6SP5
eDir 8.7.3.9

Whenever the problem occurs traceroute, ping and website access are all
unsuccessful.
Nslookup, however, is always successful.

When attempting to traceroute or ping by name, I get the following error
messages:
Unable to resolve target system name xxx.xxx.
Ping request could not find host xxx.xxx. Please check the name and try
again.

Access via the IP address is never a problem.

The fact that nslookup always works is what leads me to the assumption that
it's not a DNS server problem.

Is this a correct assumption?