I think you're confusing terms. What you need to configure is your DNS servers that look-up domain names.
On Linux there are two locations of interest here:
- you can consider this your internal DNS - since you have to add in an IP and a domain name to resolve to that IP. So if you add in:
10.0.0.1 server.domain.com server
Every time you refer to server
(in your browser for example); your machine will locally resolve the domain to 10.0.0.1
- this is a file that contains a listing of external/public DNS servers available to you. This should contain at least one public DNS that's able to resolve any domain you request - you can use the Google DNS as an example and this will work perfectly.
Another file that is of importance is /etc/nsswitch.conf
- in this file you set which DNS is looked up first (that is the internal or external as described in 1 and 2 above).
If you have a list of DNS server IP's; you need to add it to /etc/resolv.conf as described in 2. above.