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General information



  • Central service for linking unique names to Internet addresses (IPv4/IPv6) 
  • Resource records for different functionalities
  • Data is provided by so-called DNS servers
  • The DNS is organized in a tree structure with a worldwide distributed so-called root zone
  • entries are maintained by the so-called hostmaster (here
  • The service is designed via so-called Request for Comments

Since the Domain Name System is one of the most important services in the data network, this service is physically redundant here at the RWTH and operated centrally on the backbone.

The use of anycast (addressing and routing method) adds logical redundancy. Here the computers themselves are assigned all common service (IPv4/IPv6) addresses.

The information is defined by so called Resource Records, of which the following can be set here at the RWTH by authorized persons.

A Recordreturns the 32 bit IPv4 address of a computer
AAAA Recordreturns the 128 bit IPv6 address of a computer
CAA Recordspecifies which Certificate Authority (CA) may issue certificates for the domain/zone or host
CNAME RecordCanonical (alias) NAme for a computer
HINFO-Recordgeneral information about the computer such as processor type or operating system
MX Recordassigns one or more MTA (Mail Transfer Agent) to the responsible mail server
NAPTR RecordExtension of the A Record by a regular writing (for e.g. URLs)
NS RecordHost name of the authoritative name server
SRV Recordgeneral entry for a service offered
SSHFP Recordpublishes the fingerprint of an SSH host_key so that verification can be done in a second way

To achieve an administrative and logical subdivision within a domain (e.g., zones/subdomains are used.

Via the DNS-Admin, registered network contacts can either make entries for the entrusted zone/subdomain themselves or request an entry by sending an informal e-mail to

The following DNS are available within the university:



Important links:

Most relevant Articles

CAA (EN)SSHFPRequest DNS Entry