ICS
Although ICS is discussed separately from NAT, it is nothing more than an implementation of NAT on Windows platforms since Windows Me. ICS makes it very simple to share an Internet connection with multiple systems on the network.
Because ICS was intended as a simple mechanism for a small office network or a home network to share a single Internet connection, configuration is simple. However, simplicity is also the potential downfall of ICS. ICS provides no security, and the system providing the shared connection is not secure against outside attacks. For that reason, ICS should be used only when no other facilities are available or in conjunction with a firewall application, which later versions of Microsoft Windows, such as XP, now include.