fw.gsnet.ch has no CNAME records.
Question and response
Question
dig fw.gsnet.ch. NS
Answer
The response has no answer records.
Authority
gsnet.ch. 300 SOA ns1.flashcable.ch. hostmaster.gib-solutions.ch. 2016071911 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0