Page is a not externally linkable
-- Domain Names
---- CNAME Versus 301?
mcavic - 12:31 am on Feb 11, 2010 (gmt 0)Thread source:: http://www.webmasterworld.com/domain_names/4077074.htm
Short answer - yes, the 301 is highly recommended. Mainly because search engines will have half as many pages to index, and may therefore be able to index your site more fully.
Brought to you by WebmasterWorld: http://www.webmasterworld.com