Sample network configuration.

In the picture above the network configuration considered for tests and following scenarios is shown. 192.168.0.2 and 192.168.0.3 are internal hosts, with private network addresses. Host 192.168.0.1 acts as a gateway, and does NAT MASQUERADING and filtering of all connections. In this configuration, all machines are supposed to have ipfire installed. Internal hosts are connected by means of a simple HUB, while connection with external Internet is assured by a modem, with IP address dynamically assigned and shown above as 80.111.114.96. This address changes every time a connection is established with the Internet Service Provider, and so may vary in IPFIRE outputs that will be shown in next pages.