Computer registration

The TU Darmstadt data network is jointly operated by HRZ and the institutes of the TU. In order for your computers to have access to the internet, all computers connected to the university network must be registered at HRZ.

In this way, the information necessary for the operation of central network components (routers, name servers) is also collected. This information serves as a basis for planning and as an assistance in case of failure. The only information requested besides the location concerns the network hardware.

For each department there is one LAN representativewho is responsible for basic network issues.

Computer logins are sent from the domain administrator to the mail address with the subject line: [netdb].

Domain administratorsare responsible for the logical order in their domain, the namespace. They are assigned a subnet according to their requirements. They assign the computer names and ensure that the names are unique within their domain.

>> Information and documentation on the tasks and duties of domain administrators (opens in new tab) .

Subnetwork administrators are responsible for the subnetwork assigned to them. They assign unique Internet addresses (IP addresses) in this area. Normally, domain administrators are also subnet administrators.

ATTENTION: There are no manual changes possible in the network database on Fridays!

The following tool is available for computer registration and deregistration:

  • Computer registration:
    Fill in the mandatory fields of the form and press “Add”. This way you can also register several computers one after the other. Your registrations will now be added to a queue, which you can access via a menu bar on the left.
  • Computer deregistration:
    Enter the IP address or the host name of the computer to be deleted and confirm your entry. Your change request will also be added to the queue.
  • Automated reading in:
    Either download the file in the queue and send it with the subject: [netdb] to , or send it directly to the machine.
    Due to the automatic processing, the response is already available after one hour.


The registrations are only accepted by the administrators registered for the respective domain. For this purpose, the TU-IDs stored in the database for the domain are compaired with the e-mail addresses in the registration e-mail.

Therefore, please make sure that all TU-IDs are listed in the domain database that are supposed to make computer registrations for the respective domain and that all valid e-mail addresses are listed in the IDM portal.

The limitation to two administrators per domain has been dropped.

FAQ: Questions and answers

You can find current host lists here.

In a /30 and /29 subnet, all IP addresses can be assigned except the network, gateway and broadcast address.

From a /28 subnet and larger, all addresses can be assigned by the institute, except the network, gateway and broadcast address and an additional IP address below the gateway address.

If a computer name or IP address is changed, the old entry must first be deleted (enter an “L” in the status field). Afterwards, a normal new registration (status = “N”) of the computer is carried out.

If other fields (e.g. hardware address or supervisor) are to be changed, it is sufficient to resend the logon record with an “A” in the status field.

The MAC address is a globally unique number of the network card and is assigned during manufacture. It is required by the HRZ for troubleshooting and in some areas for IP allocation (DHCP/BOOTP) and security. The address is usually represented as 6 two-digit hexadecimal numbers separated by dashes or colons, e.g. 00:00:C0:11:24:4a

If the MAC address is displayed as 44-45-53-54-00-00, this is not correct! (see below).

How do I find out the MAC adress?

On almost all current network cards there is a sticker with the MAC address, often with the addition “Node Address” or “Hardware Address”. The serial number may look similar, but usually has nothing to do with the MAC address.

How do I find out the MAC adress using Windows?

From the command line you can use ipconfig /all to output the network configuration. The MAC address is the physical address.

How do I find out the MAC adress using Linux?

With /sbin/ifconfig you get the interface data displayed. The MAC is the HWAddr for the interface eth0.

How do I find out the MAC adress using MAC OS?

In the apple menu you can access a screen via Apple System Profiler/Network Overview/AppleTalk. There you find the MAC address as hardware address.

IPv6 addresses can also be registered with the new computer registration tool. A short explanation can be found on the HRZ pages, for further questions please send a short mail to .