vim /etc/resolv.conf
Edit file - usually you would have:
nameserver 8.8.8.8
nameserver 8.8.4.4
possibly:
domain local.example.com
or:
search local.example.com
This will help you with searches like:
host hostname
rather then
host fqdn
Adding more than one DNS entry is important from the redundancy point of view - if one fails you can still resolve names.