MCSA/MCSE Self-Paced Training Kit (Exam 70-270): Installing ...

Lesson 4 Configuring Internet Connection Sharing (ICS)
15-43
Setting up ICS on a small network consists of the following general steps:
1. Make sure that the computer that will become the ICS computer is properly connected
to the Internet.
2. Make sure that the ICS computer and the other computers are properly connected
to one another via a local network.
3. On the ICS computer, enable Internet Connection Sharing on the network connection
for the Internet.. This is done by selecting the Allow Other Network Users To
Connect Through This Computer’s Internet Connection option on the Advanced
tab of the network connection’s Properties dialog box. When you enable ICS, the
ICS computer configures itself with the IP address 192.168.0.1 and also becomes a
DHCP server for the network, so that it can provide IP addressing information to
other computers.
4. Configure the remaining computers to obtain their IP address and DNS server
information automatically and restart the computers. When each computer
restarts, it will obtain addressing information from the ICS computer and should
be able to connect to the Internet. IP addresses of the computers will fall in the
range 192.168.0.2–192.168.0.254.
ICS Limitations
Because of what ICS does for a network (IP address allocation, name resolution, and
acting as the network’s gateway), and because the IP address the host computer uses
is always 192.168.0.1 with a subnet mask of 255.255.255.0, several conditions must be
met while ICS is used:
■ The IP addresses of the computers on the network must also be in the 192.168.0.x
range, and the subnet mask must always be 255.255.255.0. If network computers
cannot use these addresses, ICS does not work properly.
■ Windows 2000 Server or Windows Server 2003 servers configured as domain controllers,
DNS servers, gateways, and DHCP servers cannot be used on the network.
ICS is intended for use only in a workgroup environment.
■ Computers with static IP addresses that do not fall in the ICS range do not work
with ICS.
■ If more than one network adapter is available, and if two or more LAN connections
are configured and all of them connect to computers on the network, those
connections need to be bridged. Bridging a connection is as simple as right-clicking
the connection and selecting Bridge Connections.
■ ICS must be enabled from the dial-up, VPN, broadband, or other connection to the
Internet.