Canonical redirect of subdomains

[MarieN]

We've added a canonical redirect on my site example.com from http://example.com to the www version. I have subdomains that also have a fair amount of inbound links and good search rankings, for example: http://topic.example.com.

is there a way to redirect this page to the www version also? That would be to: http://www.topic.example.com. I am mainly concerned about SE's seeing the top domain as a separate domain altogether.

Would it be better to move it to: http://www.example.com/topic from an SEO standpoint?

Also, how is the last slash in a domain name looked upon by the search engines? F. ex:

http://www.example.com

versus

http://www.example.com/

and

http://www.example.com/topic

versus

http://www.example.com/topic/

Do the SE's count these as separate pages?

[edited by: tedster at 6:01 pm (utc) on Sep. 7, 2008]
[edit reason] switch to example.com - it cannot be owned [/edit]

[tedster]

The canonical problem between example.com and www.example.com comes up because so many web servers have been configured to resolve either one by default.

There is no such problem with the www.topic.example.com -- your server won't resolve the request for the hostname "www.topic" unless you configure it to do that.

Some people do configure their server to resolve www.topic.example.com, usually as a service to cluelss users who always type the "www" no matter what. That configuration could cause a canonical problem unless the "www.topic" hostname resolves via a 301 redirect to the hostnmae "topic". But the situation doesn't come up unless you actively create it.

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Whether a subdomain or a directory is "better" for SEO is an ongoing discussion. The most recent chapter is here: [webmasterworld.com...]

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About the trailing slash - yes, technically the trailing slash makes a difference. If "/topic" is not a page but a directory, then you should be diligent about using a 301 redirect to "/topic/".