http:// and http://www. - Can They Be Treated As One?

We all know search engines treat http://www.site.com and http://site.com as different websites, however I have heard through using the Google WebMaster Tool they can be treated by Google as one.

If this is true how? Where do I go on the Google Webmaster interface?

Also, I've heard using robots.txt would work. How would I go about creating a robots.txt to allow http://www. but not http://?

 

Assuming you have submitted your site

1. Go to the webmaster tools
2. click on your website
3. Click on settings

Now you should see preferred domain.. now just choose..

However make sure when you are linking to your pages you use only one way

 

So when I'm building backlinks only link to what I set my preffered as?

 

Always set the preference, yes. But you also want to 301 redirect the non-www to the www. That's for the cases when people don't do it right.

If your server allows .htaccess and has mod_rewrite installed, you can do this:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.directory-empire\.com [NC]
RewriteRule (.*) http://www.directory-empire.com/$1 [R=301,L]

Code (markup):

That will permanently rewrite all the non-www requests to the www ones. You can also set it GWT for extra measure.