Q. How do I edit dns configuration file to add my ISPs nameservers?
A. You need to edit /etc/resolv.conf file to set nameserver. Name server IP address Internet address (in dot notation) of a name server that the resolver should query. Up to 3 name servers may be listed, one per keyword. If there are multiple servers, the resolver library queries them in the order listed. If no nameserver entries are present, the default is to use the name server on the local machine.
Edit /etc/resolv.conf using a text editor such as vi or nano or gedit:
# vi /etc/resolv.conf
Appnd namesever as follows:
Save and close the file. The algorithm used is to try a name server, and if the query times out, try the next, until out of name servers, then repeat trying all the name servers until a maximum number of retries are made.