2 sites pointing to the same document root

[albert0346]

Hello,

I have a question to the info I got from Google Webmaster Tools:

Under "Links to your site" I found links from one of my 2 sites. This linking site points to the document root of my other site. So if a user uses www.site1.com she/he comes to www.site2.com. And www.site2.com is shown in the address bar. This is NOT implemented with a 301 redirect. So my question is: Does Google consider this as 2 different sites with duplicate content? If yes, how I can I get rid of this problem?

Thanks a lot in advance for your answer.

Albert

[levo]

How did you implement it?

[lammert]

My experience with 2 different domain names pointing to the same DocumentRoot is that it won't change the site name in the address bar while typing one of the domain names in the address bar. If wwww.site2.com is visible in the address bar after you entered wwww.site1.com, something must have signaled the browser that the content should be accessed via that secondary domain name instead of www.site1.com. It looks therefore that some sort of redirect is already used on your domains. This is not necessarily a 301 redirect. It can also be a conditional HTTP meta refresh for example which is executed on the browser side. You have to find out how the redirect currently takes place. Depending on the way it is implemented, it could either be harmful to your SE rankings or not.

In general 301 redirects are safe. Other types of redirects may also be safe if the canonical link tag is used to signal the search engines which is the preferred URL.