I have run zone alarm on networks using the free version. All I did was add a range of IP address being 192.168.0.0/24 as being trusted zone. This worked ok ... your gonna have to tweak to get it right though... your best bet is a DSL router with a hardware firewall . at the moment we are selling Vigor 2600 devices. You get a DSL router, Firewall and VPN server for I think £260.00.... well worth it... other member may be able to recomend cheaper alternatives as you wont need the VPN server.