Apex domains cannot have CNAME records.
Question and response
Question
dig eclipse.net.uk. NS
Answer
eclipse.net.uk. 5 NS dns1.as12513.net.
eclipse.net.uk. 5 NS dns1.eclipse.net.uk.
eclipse.net.uk. 5 NS dns2.as12513.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0