The .DE registry has certain requirements for nameservers that can be applied to .DE domains. Some of those requirements are that the nameserver IP addresses must be in separate class C networks, and that the nameserver must provide SOA.
Denic has created a tool on their website where you can check to see if your nameservers are valid for their system before setting nameservers for your .DE domans. You can check the nameservers at DENIC's ZoneCheck (http://www.denic.de/en/background/nast.html).
There you can verify if the nameserver for a domain was configured properly and if the zone complies with the DENIC domain guidelines.
If no error is reported, you can then configure the nameservers to work with your domain. If you do get any error, you'll need to contact your DNS provider, and show them the error messages to fix this situation.
For using .de domain names with our hosting @ WESH UK, you will need to set your name servers to:
Once set, you can then use the advanced DNS settings to put in your IP address (Found in your welcome email and in the left side of cPanel) into the A record as follows:
Record type: "A record"
Address: "Your servers IP address" (This is in your hosting account welcome email and in the cPanel info pane)
Alternatively, just drop us in a support ticket and we will set the whole lot up for you asap :-)