The Domain Name Service is the usual way to resolve IP-numbers from hostnames in larger networks. Assuming you already have a name server running, all you have to know to set it up is your domainname and the nameserver's (and maybe it's secondaries, if any) IP-numbers. Put all these informations into `/etc/resolv.conf':
# Example /etc/resolv.conf domain your.domain.here nameserver <primary-IP> nameserver <secondary-ip>
As an example, here's DUSKs `/etc/resolv.conf':
# dusk's /etc/resolv.conf domain rz.uni-regensburg.de nameserver 188.8.131.52 nameserver 184.108.40.206
This file is all that's necessary to use DNS. Probably most important, there's no need to reboot after creating/changing this file.