You don't say what distribution you are using, so the file might be somewhere else, but what you need is to edit /etc/resolv.conf
, and include the line
This file is used by the name resolver library routines to turn a DNS name into an IP address. The search
string will be appended to any DNS name that does not contain a dot in it. For a fuller explanation, there is a manpage for resolv.conf that explains all the options that can go into that file.