Hi, I've configured my squid proxy to use NTLM authentication. When I access to internet from a PC with Firefox, an authentication window appears: Please write username and password for proxy "" on testproxy:3128 I write user and pwd, but the same window appears. If I press ESC (close window), another window appears: Please write username and password for proxy "Squid Test Proxy" on testproxy:3128 The only difference is the proxy name, but after I wrote user and password the proxy works! Why the proxy is acting in this mode?