Hello Raddo.

If there is some domain controller against which you can authenticate (and is accessible for application), it is possible. Regarding your Firewall settings, I would recommend to consult your network administrator in this matter, who is familiar with your environment and setup.

Regarding your second question, Mixed mode authentication allows users to log-in both via AD credentials (Windows authentication) and Kentico user credentials (Form authentication). It can be configured according to this article.

Best Regards,
Radek Macalik