After the installation of a (non-master) UCS system the next step is to join the system into the UCS domain. There are several requirements in order to successfully join a system. All these requirements are checked before the actual join during the installation/setup or the manual join via the Univention Mangement Console (UMC).
If these checks fail, the join is aborted. Normally a re-installation is not necessary, just fix the problem and try to join again (as root via the UMC → “Domain Join” module, or via the univention-join command line tool). Below a list of requirements and some information on how to fix potential problems can be found.
DNS settings:
The join tries to find the name of UCS master system (host -t SRV "_domaincontroller_master._tcp.$(dnsdomainname)") for all configured DNS servers. If this fails, please check the UCR variables nameserver1, nameserver2, nameserver3 and verify that one of them is set to the UCS master system’s IP address.
Network connection:
If a ping to the UCS master system fails, the join is aborted. Please check that the master system is online and reachable (ping $master).
SSH login:
In order to join the ssh login of the join user (normally Administrator) on the master system has to be possible (ssh Administrator@$master). Make sure the join user is member of at least one of the following groups: Domain Admins,DC Slave Hosts,Computers,DC Backup Hosts
UCS version:
The UCS version of the UCS master cannot be lower than the version of the joining system. If the joining system has a higher version, the master has to be updated first (or the system has to be re-installed with the appropriate UCS version).