From time to time, sites are migrated, moved or renamed. In that scenario, there is a whole host of things are changed both in SharePoint and in the external network.
To localhost or not?
I come across this error a number of times. Junior consultants access SharePoint via http://localhost and then cannot understand why the site doesn’t work as expected. The reason for this is pretty simple. The default IIS website (running on port 80) will be available, but when navigating to list pages and site settings, you will either see the roots lists OR you will get an error.
Other functionality will give funny errors or will simply stop working (InfoPath Form Services being one.
Alternate Access Mappings
SharePoint uses alternate access mappings to “translate” the URL received. This capability allows us to use multiple URLs to access the same content. For example, we can have http://intranet.sps.co.za (for internal users) and http://extranet.sps.co.za (for external users). Both URLs, from a DNS perspective, will point to the same logical IP / server, but once it hits the SharePoint server, it will be translated and pointed to the correct IIS web application based on SharePoint’s rules.
Alternate access mappings is often overlooked as a critical part of the configuration as many “basic” sites either do not use it, or have it pre-configured for their default web application.
I hope me sharing this small post, will give the consultant experiencing some funnies another tool in his arsenal when troubleshooting SharePoint.