Google Indexed URLs Going Down?

Technical Question Re: URLs and Google Crawler/Indexing/Retrieval

• We changed the DNS for website www.aaa.bbb.com to be an alias for website aaa.bbb.com, and currently both URLs resolve to the same set of web servers. We are contemplating moving www.aaa.bbb.com to a URL rewriting server (so users will always get redirected to a aaa.bbb.com URL) and are trying to determine if there will be any resulting issues for Google users. For example, will both www.aaa.bbb.com and aaa.bbb.com get indexed? If so, will both URLs appear in the search results? Is one approach (alias/web server vs. rewriting server) better for the Google: crawler, indexing, or retrieval? Thanks PS - the Google link tool treats "www" as a stop word. Hence, both URLs returned identical results.

• Answer:

  Hi anneb-ga! Search engines generally "fold" similar information into single results. You won't harm your Google index (or any other search engine index) by having two sites reference the same page, but only one will appear in the listings. Generally, the page with the higher rank will appear. I've found a lot of information on this topic by searching Google for the words "duplicated content penalty google": This forum: http://forums.seochat.com/showthread.php?t=8510 Has a post that says: "Duplicate content doesn't leed to a penalty, but plese note that Google will only display one copy in the SERPS, normally the one with the higher PR." In other words, the highest ranked page will be the one the users will see. No matter which approach you choose, rewriting or DNS aliasing, you'll very likely end up with the same results. In both cases, the search engines will choose only one of your sites (whichever is the most popular) to present to the user as a search result. Since both of your sites are going to be identical, it should not matter which is presented as the result. In this case, I would suggest the easier route and using a simple DNS alias. For an example of a very popular site using a technique like this, please see "www.msdn.microsoft.com" and "msdn.microsoft.com". Please let me know if I have answered this question with enough detail. If you require more information, don't hesitate to ask for an answer clarification. Regards, mmastrac-ga