does someone know how to configure the reverse authentication properly? What is meant with "frontend realm"? There is also no option to bind this to a virtual webserver instance.
I managed to get my hands on the "online help" for reverse authentication. So here are some guidelines for configuring your profille:
On the Webserver Protection > Reverse Authentication > Profiles tab, you specify authentication profiles for the web application firewall. With profiles you can assign different authentication settings to different users or user groups. After specifying the authentication profiles, you can assign them to site path routes on the Web Application Firewall > Site Path Routing tab. To add an authentication profile, do the following: 1. On the Profiles tab, click New Authentication Profile. The Create Authentication Profile dialog box opens. 2. Make the following settings: Name: Enter a descriptive name for the profile. Frontend mode: Select how the users should authenticate at the web application firewall. Basic: Users authenticate with HTTP basic authentication, entering username and password. As the credentials are sent unencrypted with this mode, it should be used over HTTPS. With this mode, no session cookies will be generated and a dedicated logout is not possible. Form Template: Users will be presented a form where they have to enter their credentials. With this mode, session cookies will be generated and a dedicated logout is possible. The form template to be used can be selected in the Form template drop-down list. Besides the default form template, the list shows the forms that have been defined on the Form Templates tab. Frontend realm: The realm is a unique string that is used to define the path to the URL authentication form. It is important to enter a string that is not used as a path on the related real webserver, otherwise the real webserver path would not be accessible by the users. Form template: Select the form template that will be presented to the users for authentication. Form templates are defined on the Form Templates page. Backend mode: Select how the web application firewall authenticates against the real webservers. The backend mode has to match the real webserver's authentication settings. Basic: Authentication works with HTTP basic authentication, providing username and password. None: There is no authentication between the WAF and the real webservers. Note that even if your real webservers do not support authentication, users will be authenticated via the frontend mode. Users/Groups: Select the users or user groups or add new users that should be assigned to this authentication profile. After assigning this profile to a site path route, these users will have access to the site path with the authentication settings defined in this profile. Typically, this would be a backend user group.