How can an external DNS server be used in a UCS environment?
If it is necessary to use an external DNS server, there are two basic possibilities for using it in combination with a UCS environment. Either the name server is integrated in the domain or the UCS environment is set up within a subdomain.
To implement the first version, all the name servers running on the systems must be stopped. By default this is the case on the domain controller master, the domain controller backup and the domain controller slave. In addition, the systems must be notified of the new DNS server. This is done by specifying the new DNS server as the primary name server for the UCS server systems. Within the UCS environment, some DNS service records are entered on the DNS servers after the installation. As these are urgently required for the functioning of the UCS systems, they need to be added on the external DNS server by hand. For example, the ?_domaincontroller_master._tcp? service record is used to identify the domain controller master during the join procedure.
Further information and a list of service records can be found in the SDB article DNS service records and DNS alias entries in UCS.
The second possibility consists in defining a separate name area within a subdomain for the UCS environment. For example, all the systems would be installed within the domain ucs.univention.de. The domain controller master would be specified as the primary DNS server. The external DNS server responsible for the name area ?univention.de? must be entered as the DNS forwarder accordingly. Inversely, a corresponding entry needs to be entered on the external name server which forwards the requests to the subdomain ?ucs.? to the domain controller master. This not only renders the adaptation of the service records of the external DNS server unnecessary, but also performs a logical separation between UCS and third-party systems.