A increasing popular issue these days is Home Networks and the ability to share an Internet connection between the LAN (Local Area Network) Computers.

I propose here to only give you a set of brief guidelines for Internet Sharing, LAN's and Firewalls as the Internet is full of so much technical information on "How to do it" You could use the Google search engine to locate an information site or I recommend some sites such as:

http://www.directron.com/howtobuilhom.html

http://www.madmick3006.com/networking.htm

The Hardware, Network Cards (NIC's) are inexpensive and the Software is included with the Windows Operating Systems. If the installation and setup instructions are followed carefully then it is a relatively painless exercise to have a useful LAN which will allow sharing of Files, Printers and the Internet. If your Network is to consist of only two Computers then a Network Card for each Computer and a special Cat 5 cable (cross-over connections) is needed to join the Network Cards together.

Should you have (or think you may in the future have) more than two computers in your Network then you need a Hub to act as the junction for the cables from each Computer. Every Computer has a NIC and a length of Cat 5 cable connecting the NIC to the Hub. Nic's and cables may be purchased from any Computer Store either separately or as a starter pack.

Care should be taken when installing the driver for the NIC (mostly supplied on a diskette accompanying the NIC) as this is the area where many people fail to complete the task successfully. Without the NIC working correctly it will be impossible to setup the Network.

This is made more difficult when there is only two Computers in the Network as it is difficult to determine which Computer is not working correctly. When installing the driver you will most times be asked for your Windows Operating System CD ROM. Be aware that sometimes the installation routine will access files from the diskette, then the CD ROM and finally maybe back to the diskette. Failure to "find" the required files on the diskette in this third stage and your failure to "point" the installation to the diskette will cause a faulty NIC installation which may not show up in the device manager.

Having properly installed the NIC's and cabled the Computers either to the Hub or with a cross-over cable the next step is to setup the software. The only protocol you need to use these days (with very few exceptions) is the TCP / IP protocol.

This protocol is needed (and mandatory) to enable Internet Connection Sharing which is sharing your Dial-up Modem connection or your ADSL or Cable connection with the other Computers on your Network.

You need to give each Computer a unique name (Bill or Study etc) and put then in the same Workgroup (Home or Office etc). File and printer sharing needs to be installed if you intend to share files or printers and the each drive or printer needs to be specifically shared via the properties for that drive or printer.

If, and only if, with the only the TCP / IP protocol installed, you can access each Computer and or Printer from any Computer proceed to the next stage of Internet connection sharing .

Internet Connection Sharing (ICS) is available with all current Microsoft Windows Operating systems. If you have a Dial-up Internet account then this software will use this account and allow other LAN Computers to access the Internet via your Computer which has the Modem attached.
Note: This Computer must be on and connected (on-line) to share the connection.

If you have a Cable or ADSL(Broadband) Internet account the Computer which has the Cable or ADSL Modem attached will share this connection. You need to be careful when setting up the ICS that you identify which NIC in this Computer is for the Cable or ADSL Modem and which NIC is for the LAN. Note: This Computer must be on and connected (on-line) to share the connection.

On the Computer with the Modem or (Server), use the Control Panel "Add-Remove Programs" .. Communications subsection.. Add ..Internet Connection Sharing. Follow the prompts to install the software.
You need not make the diskette for the other Computers (Clients) when prompted as providing your network is functioning with the TCP / IP Protocol the others on the Network will be able to access the Internet each time the Server is connected.

With a LAN and ICS you must use fully functional Virus Scanning software with current and regularly updated data or signature files (suggested  every second day) as many viruses today spread rapidly through a LAN cross-infecting each Computer.

A " Software" Firewall is recommended for the Dialup modem connection and is mandatory for ADSL or Cable users as their "Internet Address" is more permanent and more likely "probed" by Hackers and others intent on creating havoc. The most popular software at this time is Zone Alarm which is available free to non-commercial users. www.zonelabs.com

As can be appreciated, the need to have the "Host" Computer turned on at all times to allow other Computers on the LAN to access the Internet may become a nuisance. With a Cable or ADSL connection there are many Broadband Routers available which make the actual connection to the ISP and then provide "Private" IP Addresses to all the Computers on the LAN. By the nature of these units they provide "Hardware" Firewall protection by "masking" the LAN Computer address'. Such Routers also provide the functions of a Hub allowing the LAN Computers to connect and share data, printer and Internet.

I recommend the D-Link range of Broadband Routers and presently use the DL-714P+ which includes a "Print Server".  This means your printer connects directly to the Router and any Computer on the LAN may print without the need for a traditional printer host computer being turned on.

Broadband Internet is set to increase in popularity as the pricing moves to a more economic level and certainly once a user has experienced permanent connection as provided by Broadband they will want that convenience and speed forever. Dialup will survive, however I predict the number of ISP's will slowly decrease and future generations of new users will only consider Broadband. Dialup was only an interim measure until Broadband Technology was able to provide speed and reliability at a reasonable price....