SharePoint and IIS Sites Unavailable From Localhost

Also seen as:

  • search is running but no results returned
  • search errors in event log (can't access content, etc.)
  • you can access sites fine from other boxes but not from the local server
  • only seems to happen for URL's (http://sitename1, http://sitename2) that are different then the host name (http://servername).

Windows Server 2003 SP2 and newer (Windows Server 2008) have a Anti Denial Of Service feature that prevents the server from accessing itself via different names (that's the simple answer).

Fix (assuming you want to keep your custom URL's):

  • Set a registry value to turn off this security feature (I still don't understand the specific type of attack that it's preventing)
  • Set a registry value to a list of all the cname's your server goes by.
Further Info: Rant:

In the KB Microsoft basically says "don't turn it all off unless your lame", so your left with "edit the registry every time you add a website".  This is a cumbersome workaround for something that happens out of the box default.  Most SharePoint boxes will want more then one web site name and best practice says to NOT make production sites the server name. IMO SharePoint should be updating the reg key itself and keep in sync with the host headers created/managed by central admin. Or, the localhost loopback "new feature" should be looking at iis host headers and allowing them.