Hi @Benjamin Fellner , yes it's possible to connect OPNsense to Azure AD for user authentication. One way to achieve this is by using Azure AD Domain Services (Azure AD DS) and setting up LDAPS. Azure AD DS provides a managed domain service with LDAP, which you can use to authenticate users via LDAPS for VPN access on the OPNsense firewall.
Another option is to use Azure Virtual WAN User VPN (point-to-site) with Azure AD authentication for OpenVPN protocol connections. This method allows users to connect to your VNet using Azure AD authentication.
Please let me know if you have any questions and I can help you further.
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