ns4.above.com has no CNAME records.
Question and response
Question
dig ns4.above.com. NS
Answer
The response has no answer records.
Authority
above.com. 10449 SOA ns1.trellian.com. hostmaster.trellian.com. 2026020400 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0