Requests to register or update .de domains are handled by a robot doing the following checks on registry side:
- are all name servers given in the request reachable?
- are they authoritative?
- Do their answers contain the "authoritative answer" (AA) bit and do they know about the other authoritative name servers?
- are all authoritative name sersers given in the request?
- are values in the SOA records in the ranges required by the DENIC?
- are the SOA values identical for all name servers?
- do at least two of the three name servers differ in the first three bytes of the IP (v4) address?