I'd be very grateful for advice on OS X Leopard Firewall settings. I'm a recent switcher/newbie. At the moment, by default, System Preferences>Security>Firewall is set to Allow All Incoming Connections. What I'm trying to achieve is an active Firewall (not sure that's the case on my machine at the moment) set to a medium level of security. Questions: is the Firewall automatically on? If I opt for Allow Only Essential Services, do I prevent access to run of the mill, day to day web pages - on-line banking, newspapers, train timetables and so forth? I'd be very glad of any guidance. Actually, just to know I have an active Firewall would be enough.