I am required to develop an Intranet application using ASP.NET and C#. What's the differences between Intranet application and Internet application? What should I do to MAKE SURE this application is ONLY run in the intranet?
If I required the user to login in order to access to this application, would this login page be seen from the internet?

Thank you!

An intranet application is a web application that uses Windows authentication so only users in your network can access the application. The difference between an intranet application and an internet application is the type of authentication used intranet application uses Windows while internet application uses Forms authentication. Intranet application can get complicated because of permissions delegation by Windows during authentication. The first link is security of web application by Microsoft and I have covered how to use authorization section with ACL(access control list) for Windows authentication. The most important think to know about ACL leave the everybody group alone because Asp.net is also a member of that group. Hope this helps.

http://msdn2.microsoft.com/en-us/library/ms978378.aspx

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2083133&SiteID=1

An intranet application is a web application that uses Windows authentication so only users in your network can access the application. The difference between an intranet application and an internet application is the type of authentication used intranet application uses Windows while internet application uses Forms authentication. Intranet application can get complicated because of permissions delegation by Windows during authentication. The first link is security of web application by Microsoft and I have covered how to use authorization section with ACL(access control list) for Windows authentication. The most important think to know about ACL leave the everybody group alone because Asp.net is also a member of that group. Hope this helps.

http://msdn2.microsoft.com/en-us/library/ms978378.aspx

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2083133&SiteID=1

If you want to make sure your app is only run for intanet user then you can define in the access list in few places.
your web browser, your firewall, you application (by getting IP of the connected client and define which range is intranet and allow to access)

best place to restrict the access is your firewall and/or web server IMO.