Proxy not working
Hello, from Terminal Servers, it is not possible to browse the Internet via FortiGate's explicit proxy from the Firefox browser, while there is no problem with Chrome or … (read more)
Hello, from Terminal Servers, it is not possible to browse the Internet via FortiGate's explicit proxy from the Firefox browser, while there is no problem with Chrome or Edge. When the user tries to browse external sites, the proxy sends the error page "You need to authenticate to use this service". It seems that Firefox does not pass user authentication to FortiGate. The proxy authenticates users per session via Kerberos tickets.
Firefox version: 115.5.0esr
I also performed the following settings to pass the Kerberos ticket to the proxy without success: https://people.redhat.com/mikeb/negotiate/
I also noticed that it is not possible to change the "network.negotiate-auth.allow-proxies" setting from "false" to "true." Is this my problem? Is it normal that it cannot be changed?
Attached are the settings.
Thank you in advance.