DENIC, which is the German registry for all .DE domains, has a number of strict rules for nameservers.
You can perform a nameserver check on their website via https://www.denic.de/en/service/tools/nast/. The results will show which of their rules are not met, and more information on how to meet the requirements.
Errors when changing the nameservers
When you receive an error after changing your nameservers, it is often because of misconfigured nameservers. In this case, use the Nameserver Check on DENIC's website to check if your nameservers are configured correctly.
If your control panel shows an error, you will see at least one error message when performing the check on DENIC's website. More information about the errors will also be shown on the same page. We will explain one of the most common errors below:
The error message "Inconsistent set of NS RRs" means that the configuration of your nameservers does not meet DENIC's standards. Check which NS records are in your primary nameserver and compare them to what you are trying to enter in the control panel.
The NS records of your primary nameserver have to match the nameservers that you are trying to set in your control panel exactly. This information is checked by DENIC.
If they do not match, you can solve this in two ways:
- Make sure the NS records in your primary nameserver point to the nameservers you are trying to enter in the control panel.
- Or make sure you enter the nameservers that are in your primary nameservers, in your control panel.
After changing the (configuration of) your nameservers, perform the Nameserver Check again. If the check does not return any errors, you can retry changing the nameservers in your control panel.
Attention: The IP addresses of your nameservers can not be on the same subnet.
For instance: If your primary nameserver's IP address is 1.2.3.100, then your secondary nameserver's IP address can not be 1.2.3.101. Because the first three numbers are the same, these IP addresses are on the same subnet. In this case, change your nameservers and use an extra nameserver that is on a different subnet.