A Web Server can consider www.abc.com http://abc.com as two different web pages. As a result this will hurt the page ranking of the webpage, since the search engine will take some time to index when there are different choices. Implementing 301 redirect from non www version of the site to www version of the site will preventing in selecting one URL over another.
The following is the procedure for 301 permanent redirect using IIS Web Server. This will be easiest and strightfarword way for ASP /ASPXpages. To permanently redirect the non-www version of our ASP/ ASP.Net based website to the www version can be as followed.
1. Set up up two IIS web sites for our web site as shown in the screenshot below
Fig: Illustrating www version and non www versions of the websites setup in IIS for 301 redirect
Set up our www version as same as our website name .
2. Right Click on the website ->Navigate to the website properties - > Website tab-> Navigate to Advancedtab -> Enter Host Header Value
Fig: Entering Host Header values for the website for 301 redirect implementation
Include the www portion when entering the host header value , need to point to the DNN web files on our server.
3.Now create a second IIS website and enter the host header value without www, right click on the website navigate to Home Directory -> and point “the content for this resource” to our www URL like this.
Fig: Making Permanent Redirection Possible
The two variables ($S$Q) at the end of the URL will get appended, which ensure that all other pages besides the home page redirect correctly as well.
We need to check the 2 check boxes “the exact URL entered above” and “a permanent redirection for this resource” checked.
Now our browser will now redirect http://abc.com to www.abc.com.