Hi,
Which browser do you use? Firefox should be asking always for your AD credentials (unless you change its config and add the intranet site to trusted sites, you can use this
workaround).
IE should not ask by default, but it also depends in its security settings (
http://devnet.kentico.com/Forums/f17/t5481/tp2/Active-Directory-users-and-their-username.aspx):
This is going to sound really stupid, but I think I figured out the issue with a little more research.
Internet Explorer must consider the requested URL to be on the intranet (local). If the computer name portion of the requested URL contains periods (such as http://www.microsoft.com and http://10.0.0.1), Internet Explorer assumes that the requested address exists on the Internet and does not pass any credentials automatically. Addresses without periods (such as http://webserver) are considered to be on the intranet (local); Internet Explorer passes credentials automatically. The only exception is addresses included in the Intranet zone in Internet Explorer.
Maybe some of the updates changed the security settings. Could you please check it?
Best regards,
Juraj Ondrus