DNS
- 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 hostmaster@rwth-aachen.de)
- 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 Record | returns the 32 bit IPv4 address of a computer |
| AAAA Record | returns the 128 bit IPv6 address of a computer |
| CAA Record | specifies which Certificate Authority (CA) may issue certificates for the domain/zone or host |
| CNAME Record | Canonical (alias) NAme for a computer |
| HINFO-Record | general information about the computer such as processor type or operating system |
| MX Record | assigns one or more MTA (Mail Transfer Agent) to the responsible mail server |
| NAPTR Record | Extension of the A Record by a regular writing (for e.g. URLs) |
| NS Record | Host name of the authoritative name server |
| SRV Record | general entry for a service offered |
| SSHFP Record | publishes 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. rwth-aachen.de), 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 hostmaster@rwth-aachen.de.
The following DNS are available within the university:
| IPv4 | |
|---|---|
| 134.130.4.1 | dns1.rwth-aachen.de |
| 134.130.5.1 | dns2.rwth-aachen.de |
| IPv6 | |
|---|---|
| 2a00:8a60:0:4::1 | dns1.rwth-aachen.de |
| 2a00:8a60:0:5::1 | dns2.rwth-aachen.de |
Important links:
- Liste of DNS-Domains: https://noc-portal.rz.rwth-aachen.de/networks-view/domains
- Host-Liste (updated every 2 hours): https://netstatus.rz.rwth-aachen.de/dns/hosts
- DNS-Admin (Self-administration): https://noc-portal.rz.rwth-aachen.de/dns-admin/zones