netblocks.dreamhost.com has no CNAME records.
Question and response
Question
dig netblocks.dreamhost.com. NS
Answer
The response has no answer records.
Authority
dreamhost.com. 300 SOA ns1.dreamhost.com. hostmaster.dreamhost.com. 2026022401 1681 1800 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0