Sharing an Internet Connection Through Software
You don't have to invest in a dedicated router or residential gateway to share a single Internet connection and simultaneously protect your network. Using Internet Connection Sharing, you can turn a single computer with an active Internet connection into the functional equivalent of a router. The connected computer acts as the ICS host and shares its Internet connection. All other computers on the network route their Internet traffic through the ICS host computer.

ICS is most effective with high-speed (cable or DSL) connections, although it works acceptably with dial-up Internet connections. To share a broadband connection, the ICS host computer must have separate network adapters for the Internet connection and the LAN connection. The single biggest drawback of ICS, of course, is that the shared connection is available only if the ICS host computer is turned on.

Although ICS is included as a feature in Windows 98 Second Edition, Windows Me, and Windows 2000, we strongly recommend that you use a computer running Windows XP (Home Edition or Professional) as your ICS host. The security and usability features of this version of ICS are head and shoulders above those found in earlier versions of Windows. Most notably, the Internet Connection Firewall, found only in Windows XP, is tightly integrated with ICS and adds a measure of security that is unmatched in earlier versions.

NOTE
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The Network Setup Wizard, which runs from CD or floppy disk to set up ICS on client computers, does not work with Windows 95 or Windows 3.1. If computers running either of these operating systems are present on your network, you must configure the networking components manually to take advantage of an ICS host.
Do not use ICS on any network that includes a Windows 2000 Server (or Windows .NET Server) domain controller or any other computers running a DNS server, DHCP server, or Internet gateway. In addition, if any computers on the network are configured with static IP addresses, you may need to reconfigure them to be in the private address range that is automatically assigned by ICS.

Using ICS does not expose your computer to any security risks different from those that you should be concerned about on a computer that is directly connected to the Internet. If you're using the original release of Windows XP, however, be certain you install the security patches referred to in two Microsoft Security Bulletins: MS01-54, "Invalid Universal Plug and Play Request can Disrupt System Operation" (http://www.microsoft.com/technet/security/bulletin/MS01-054.asp) and MS01-059, "Unchecked Buffer in Universal Plug and Play can Lead to System Compromise" (http://www.microsoft.com/technet/security/bulletin/MS01-059.asp). These patches, which are also included in Windows XP Service Pack 1, fix serious security holes that could allow an attacker to exploit a weakness in the Universal Plug and Play service and shut down your computer or install a Trojan horse program. Note that any client machines that were set up on ICS by using this early release of Windows XP will also need to be patched; see the referenced bulletins for access to those patches.

Libellés : Connection, Internet, Sharing, Software, Through