CNAME: does a cname change the url that the browser displays?

Question

I have a web site www.somewhere.com and I want the alias fr.somewhere.com.

I set up a CNAME record for www.somewhere.com alias fr.somewhere.com. When a user types in http://fr.somewhere.com in their browser, does the URL in the browser remain fr.somewhere.com or change to www.somewhere.com?

Solution

It will remain fr.somewhere.com unless you have rewrite conditions configured correctly:

RewriteCond %{HTTP_HOST} =fr.somewhere.com
RewriteRule ^(.*)$ http://www.somewhere.com/$1 [R=permanent,L]

I have a cname record created for blog.legoservices.com which just points to tumblr, but all you see is blog.legoservices.com.