CNAME vs 301

[evotsi]

We have a help site setup at subdomain.example.com.

We are switching to an outside hosting company for this portion of our site. The URL for that site is: help.outsidehostingcompany.com. They recommend using a CNAME to use subdomain.example.com instead of help.outsidehostingcompany.com so that it behaves as part of our site. They also have an option to change internal links to point to this CNAME. My questions are:

1. Can we still obtain SEO benefits for subdomain.example.com if it is just a CNAME to another site?

2. If we ever switched to another host would we retain any links to subdomain.example.com, or would they just "pass through" the CNAME?

[tedster]

Credit for backlinks goes the exact URL (domain, subdomain and page) that resolves with a 200 OK status. So you would want to point to a subdomain of your own domain, not of your hosting service's domain. And if you change to another host, the CNAME would need to be changed because your content would now be elsewhere.