resolver2.opendns.com has no CNAME records.
Question and response
Question
dig resolver2.opendns.com. NS
Answer
The response has no answer records.
Authority
opendns.com. 6169 SOA auth1.opendns.com. noc.opendns.com. 1772046381 16384 2048 1048576 2560
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0