Internet connectivity is important in just about every network today, and Windows 2000 can use a number of services to make Internet connectivity easier. Several services are available to implement Internet connectivity for a network:
Network Address Translation (NAT) provides a method of allowing Internet connectivity on a network with private IP addresses, eliminating the need for public addresses for every machine that accesses the Internet.
Internet Connection Sharing (ICS) is a simplified form of NAT that has easy configuration; it is also included with Windows 98/Me. ICS is best for small networks.
Microsoft Proxy Server 2.0 acts as a caching proxy and firewall for clients accessing Internet services.
NAT is included as part of Windows 2000; Microsoft Proxy Server 2.0 is a separate product available from Microsoft. At their most basic, both of these products provide an interface between a private network and the Internet. Which service to use depends on a number of factors:
NAT provides a global way of allowing Internet access, but does not provide security. If you need to provide different Internet access to different users or different access to different Internet resources, Proxy Server is a better solution.
NAT and ICS cannot be used on a routed network, unless separate NAT servers are used for each subnet. Proxy Server is a better solution for routed networks and for networks with multiple physical locations. ...