custweb4.ilk.net has no CNAME records.
Question and response
Question
dig custweb4.ilk.net. NS
Answer
The response has no answer records.
Authority
ilk.net. 3226 SOA dns-second01.ilk.net. hostmaster.ilk.net. 2026013000 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0