Whilst investigating connection/authentication problems with a CRM/NAV connector setup I found a very interesting piece of knowledge.
The scenario was I was trying to access the NAV web services
the above worked
but when I put in the full name e.g computer name and domain
then it would pop a login window and I would have to put in my username and password.
The question is why was this happening, the services were on.
You might be wondering why this information is useful or important but it could be the reason why a program can’t access a webpage or webservice because internet explorer thinks it is an internet page when it’s actually on the server and is an intranet page.
The reason Internet explorer thought this page was an internet page was because it had a dot or period in it then it thinks it’s an internet page and not an intranet page.
I found this out on this page and this description
One difference between the Internet and an intranet is the way pages are addressed. On the Internet, webpages typically are addressed through a full domain name, such as http://www.microsoft.com. Depending on how the administrator has configured the network, the domain name is usually not needed to access intranet sites and many webpages can be accessed by typing a common name (for example, http://companypictures/). If intranet security is enabled, Internet Explorer will recognize the difference between the addresses and use the appropriate security zone settings.
So if you find yourself getting authorisation errors and HTTP Error 401 Unauthorized then one thing you should check is to see if internet explorer thinks the page is an internet page.
To get round this in internet explorer you need to add the url of the page to Local intranet in Internet options –> security –> local Intranet.