lix.btigs.es has no CNAME records.
Question and response
Question
dig lix.btigs.es. NS
Answer
The response has no answer records.
Authority
es. 3600 SOA ns1.nic.es. hostmaster.nic.es. 2026030606 7200 7200 2592000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0