Public and private network connections

In a home or small office network that has Internet Connection Sharing (ICS) enabled, there are two network connections, one public and one private

The public network connection is the connection to the Internet. Any type of modem, 28.8 or 56 kilobits per second (Kbps), ISDN, DSL, or cable modem, that is connected to the computer can provide and direct network communication to and from the Internet to all the computers on your network. The modem acts as a network adapter 

The private side of the network are the computers that are connected together as shown in this illustration The computers on the network communicate with each other and send Internet requests through the network to the ICS host computer. The ICS host computer sends the request to the Internet and then returns the response to the computer that made the request.

Using this connection model provides increased security for your home or small office network. Files and folders that are shared on any computer are protected and will not be seen by people on the Internet.

Before installing the second network adapter on your ICS host computer, it is recommended you rename the modem or network connection that is connected to the Internet. This is so you can easily identify the connection to the Internet.


Most external DSL and cable modems are connected to an Ethernet network adapter. Check the manufacturer's specifications to determine the type of network adapter you need to connect to your external DSL or cable modem.

Hardware requirements overview

Choosing your Internet Connection Sharing host computer

Network adapters overview

Modems overview

Rename a network connection icon

Steps for creating a home or small office network

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