To check your nameservers DENIC provides the tool Zonecheck. ZoneCheck is a tool to check zones and nameserver configurations. It can verify if the nameserver for a domain was set up correctly and if the zone complies with the current DENIC domain guidelines. It can check domains, which are already connected, as well as new domains, which are not registered yet. It allows you to check your configuration before registration and helps you to avoid errors during the registration procedure.