Correction: "Specify the netmask. If this is already OK then leave it. If you don't know what to use, than specify 255.255.255.0. In this case internal addresses can be between 192.168.7.0 and 192.168.7.255 (don't use 0 and 255). Note that it should be the same as eth1 in your interfaces file. Using .255 is the easiest way." Last line should be "Using 255.255.255.0 is the easiest way". Sorry about that!