Configuring Mozilla Firefox Mozilla Firefox users browsing from the same domain as the proxy may sometimes be prompted multiple times for authentication. The user should configure the browser as follows: Steps Open Firefox and enter about:config in the Location bar. Click the I will be careful I promise button. In the Filter entry field enter ntlm. Double click “network.automatic-ntlm-auth.trusted-uris” and enter: http://%3Cproxy_name%3E:8080 For example: http://XYZProxy1:8080 Click OK and close and reopen the browser.