James W. Long said:
I am thinking I should I set my forwarder to my ISP?
Usually. Frequently. Sometimes.
The "real" answer is that you forward to the DNS server that
can most efficiciently (and securely) resolve the names your
internal/local server cannot (or should not.)
Usually that is the ISP if you wish to resolve "The Internet"
and don't have another intermediate DNS server on your
firewall or in your DMZ that is more efficient or prevents
you internal servers from even visiting the ISP.
So: Two common architectures:
1) Internal DNS server(s all) forward to the ISP
2) Internal DNS server(s all) forward to the firewall/DMZ
DNS server which forwards to the ISP
Also:
3) Branch office DNS servers may forward to HQ DNS and then
one of the above takes care of the Internet.