Okay so maybe that title is a bit confusing but here is what I'm trying to do:
I have a subdomain with content at my.example.com
I want to set up something like sub.my.example.com
This does not seem to work if there is content on my.example.com However if there is not content on the first subdomain it seems that it's okay to CNAME the record to example2.org
This is my first real experiance with CNAME so I'm wondering about common errors to check for.
my.example.com is an A record and sub.my.example.com is a CNAME
EDIT I am managing the DNS though Web Host Manger (WHM) Dns records. The content is at http://vbx.knowconceptdw.net and I'm trying to set a voicemail CNAME to point to http://api.twillio.com at http://voicemail.vbx.knowconceptdw.net