Server Authentication is a special technique to protect pages from public access. You can identify that type of login, when a small dialog pops up where you have to enter username and password, as the following screenshot shows:
If you get such a dialog, you have to enter username and password in the bookmark properties (Advanced + Server Authentication)
If the fields for username and password are placed within a web page, then it is a web based login and you have to record a Check-Macro.
