Internet Connection Sharing (ICS) is a feature of Network and Dial-Up Connections that allows you to use Windows 2000 to connect your home network or small office network to the Internet. For example, you might have a home network that connects to the Internet by using a dial-up connection. In this lesson, you learn how to install ICS in Windows 2000.
After this lesson, you will be able to
Estimated lesson time: 35 minutes
ICS is a simple package consisting of DHCP, NAT, and DNS. You can use ICS to easily connect your entire network to the Internet. Because ICS provides a translated connection, all computers on a network can access Internet resources such as e-mail, Web sites, and FTP sites. ICS provides the following:
ICS provides many more features than just address translation. Microsoft has added many features to make the configuration of Internet connections as simple as possible. ICS can be fully configured and administered from the Routing and Remote Access Manager. For a simple home network, a Connection Sharing wizard can also be launched from Control Panel Connections. The wizard does not allow configuration of any options but can get a home network up on the Internet in minutes. What simplifies the configuration is automatic addressing and automatic name resolution through the DHCP allocator, DNS proxy, and WINS proxy components. Each of these components provides a simplified configuration over the full version of DHCP, DNS, and WINS servers.
By enabling ICS on the computer that uses the dial-up connection, you are providing NAT, addressing, and name resolution services for all computers on your home network. After ICS is enabled and users verify their networking and Internet options, home network or small office network users can use applications such as Microsoft Internet Explorer and Microsoft Outlook Express as if they were directly connected to the ISP. The ICS computer then dials the ISP and creates the connection so that the user can reach the specified Web address or resource. To use the ICS feature, users on your home office or small office network must configure TCP/IP on their local area connection to obtain an IP address automatically.
Before you enable ICS, consider the following:
Follow these steps to enable ICS on a network connection:
Connection Sharing is configured from within the Routing and Remote Access Manager.
Follow these steps to install Connection Sharing:
The Select Routing Protocol dialog box appears.
Figure 14.5 Routing and Remote Access Manager IP Routing menu
If you have not previously established an Internet connection, you should do so.
Follow these steps to establish an Internet connection:
If you have previously established an Internet connection, you are prompted to complete the following steps.
Follow these steps to configure Internet options for ICS:
To connect a small office or home office network to the Internet, you can use either a routed or translated connection. For a routed connection, the computer running Windows 2000 Server acts as an IP router that forwards packets between the internal network and the public Internet. Although conceptually simple, a routed connection requires knowledge of IP addressing and routing. However, routed connections enable all IP traffic between internal hosts and the public Internet. For more information, see the Small Office/Home Office (SOHO) Network to the Internet Help topic.
For a translated connection, the computer running Windows 2000 Server acts as a network address translator. Translated connections that use computers running Windows 2000 Server require less knowledge of IP addressing and routing and provide a simplified configuration for hosts and the Windows 2000 router. However, translated connections may not allow all IP traffic between SOHO hosts and Internet hosts.
In Windows 2000 Server, you can configure a translated connection to the Internet by using either the ICS feature of Network and Dial-Up Connections or the NAT routing protocol provided with Routing and Remote Access. Both ICS and NAT provide translation, addressing, and name resolution services to SOHO hosts.
As described in the previous section, ICS is designed to provide a single step of configuration (a single check box) on the computer running Windows 2000 to provide a translated connection to the Internet for all of the hosts on the network. However, once enabled, ICS does not allow further configuration beyond the configuration of applications and services. For example, ICS is designed for a single IP address obtained from an ISP and does not allow you to change the range of IP addresses allocated to hosts.
As you learned in Lesson 1, the NAT routing protocol is designed to provide maximum flexibility in the configuration of the computer running Windows 2000 Server to provide a translated connection to the Internet. NAT requires additional configuration steps; however, each step of the configuration is customizable. The NAT protocol allows for the use of ranges of IP addresses from the ISP and the configuration of the range of internal IP addresses allocated to hosts.
Table 14.2 summarizes the features and capabilities of ICS and NAT.
Table 14.2 ICS and NAT Features
|Single check box configuration||Manual configuration|
|Single public IP address||Multiple public IP addresses|
|Fixed address range for internal hosts||Configurable address range for internal hosts|
|Single internal interface||Multiple internal interfaces|
ICS and NAT are features of Windows 2000 Server that are designed to connect SOHO networks to the Internet. ICS and NAT are not designed to do the following:
Answer the following questions to troubleshoot configuration problems with Connection Sharing (NAT):
ICS is a feature of Network and Dial-Up Connections that allows you to use Windows 2000 to connect your home network or small office network to the Internet. ICS can be fully configured and administered from the Routing and Remote Access Manager. By enabling ICS on the computer that uses the dial-up connection, you are providing NAT, addressing, and name resolution services for all computers on your home network.