By using address translation instead of routing, address sharing provides an inherent security benefit. That’s because host PCs on the Internet can only see the public IP address of the external interface on the computer that provides address translation and not the private IP addresses on the internal network.
There are three main network protocols supported: NetBEUI, TCP/IP, and IPX.
The Network layer is responsible for data routing, packet switching and control of network congestion. Routers operate under this layer.