ns4.elserver.com has no CNAME records.
Question and response
Question
dig ns4.elserver.com. NS
Answer
The response has no answer records.
Authority
elserver.com. 1953 SOA ns1.godns.net. hostmaster.elserver.com. 1771804800 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0