There is a security feature in Windows that prevents certain network operations.
This will usually be a problem in two scenarios:
– You have a web front end, and on it is a website named www.mywebsite.com, if you try to access that site from ANY other computer, it works just fine, but if you try to access it from the Web Front End that’s hosting mywebsite.com, it doesn’t work!
– You have a web front end, and are trying to do search crawls of your site from the same box hosting the site. Web Crawls fail and are unable to get to the site.
There’s an easy explanation and fix for this – It’s been documented elsewhere so here are the links:
Here’s the Technet article:
Bob Fox, MSFT PFE has an even better way of turning this off, only for specific domains: