301 Redirect from default.aspx to site root

For efficient SEO, it is better that each URL should render unique data. So that means URLs having duplicate content, like http://mysite.com, http://www.mysite.com and http://www.mysite.com/default.aspx should be redirected to only a single URL having the same content. Scott Mitchell has a really nice article on this topic. But there is a catch!

AFAIK, the code below (from the article) to redirect site.com/default.aspx to site.com/ will not work if there is a sub-directory involved:

if (request.RawUrl.Equals("/default.aspx"))
{
newUrl = string.Format("{0}://{1}{2}",
                 request.Url.Scheme,
                 request.Url.Authority,
                 request.RawUrl.Remove(request.RawUrl.LastIndexOf("/default.aspx", StringComparison.OrdinalIgnoreCase)));

               context.Response.Status = "301 moved permanently";
               context.Response.AddHeader("Location", newUrl);
}

  

It looks like a bug in ASP.NET: the Request.RawUrl should NOT contain "/default.aspx" when the URL does not have that extension. I tested the above code and it works fine without a sub directory, but if the default.aspx page is under a directory, the Request.RawUrl object fails to get rid of default.aspx and hence goes in an infinite loop. I would like to know what you think about this issue. If it is indeed a bug, then the only option is to use 301-redirect using IIS rewrite rules as mentioned in Scotts article.

**Update**

The same issue is highlighted here:

http://stackoverflow.com/questions/3618022/possible-bug-issue-in-asp-net-3-5-related-to-request-rawurl-property

In one of the posted replies, a nice solution could be to use Request.ServerVariables["CACHE_URL"], but even that depends on the version of IIS and is not very reliable. So the only way is to use IIS Url rewrites.