thymin2.uni-konstanz.de has no CNAME records.
Question and response
Question
dig thymin2.uni-konstanz.de. NS
Answer
The response has no answer records.
Authority
uni-konstanz.de. 3600 SOA ns3.uni-konstanz.de. hostmaster.uni-konstanz.de. 654423249 3600 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0