The figure and examples shown in the Internet gateway configuration scenario employ a system with two Ethernet interfaces: one interface to the office LAN and the other to the Internet. It is assumed in this scenario that the basic system configuration is completed. In this scenario, the LAN hosts are enabled to connect to the Internet by using DHCP, NAT, and a basic firewall that limits inbound connections.

For the examples shown in this scenario, it is assumed that you have completed the configuration shown in the basic system scenario (see Scenario: Basic System Configuration).