Networking → Broadband Connection Sharing

An IP Address is a unique identifier that your Internet Service Provider
(ISP) uses to tell your computer apart from the millions of other computers on the Internet. This whole business of having to "share" your broadband connection is usually due to the fact that your ISP will only support one IP address.

A. Multiple IP Addresses
Some ISPs, however, will gladly sell you more than one IP address for your other computers a for a nice monthly fee.

Advantages

• Simplest to set up... and your ISP will help you, since they sell this service!


• Gives you the most flexible connection. You get the same access from all your computers.
  
• Doesn't require multiple NICs in a computer.
  
• Computers operate independently. Only the computer accessing the network (and the hub it's connected to) need to be on.
  
• Works with any operating system, as long as TCP/IP is supported

Disadvantages

• There is usually a monthly cost.
  
• All of your LAN traffic could be exposed to the Internet.
  
• All of your computers are exposed to possible hacking, if they are not properly secured.

B. Using a Proxy Server
A proxy server is a software application that takes the one IP address that you get from your ISP and routes the data to and from the other computers on your LAN though it.

Advantages

• No monthly cost.
  
• Can be expanded to handle many computers.
  
• Flexible control over who can access the Internet, when, and where from (access management).

Disadvantages

• Requires that the computer running the proxy program be running for other computers to access the Internet.
  
• Need to set the internet applications in each Client computer to point to the Proxy computer. (This is a major pain if one of your Client machines is a laptop that you use in more than one network.)
  
• Can be difficult to set up.
  
• Doesn't support some applications, especially multi-player
  web gaming.
  
• No products available for Macintosh OS.

C. Using Linux (or other UNIX variants)
Linux is an (essentially) free version of Unix that is available for both the Intel
and Motorola computing platforms.  It can be configured in various ways to allow you to share your cable modem connection.

Advantages

• Free.
  
• Very flexible.
  
• Can run on slow, old (486) machines.

Disadvantages

• Usually requires a dedicated computer.
  
• BIG learning curve.
  
• Hard, if not impossible, to set up by non-technical users.

D. Using Microsoft NT If you are using NT Workstation or Server, and your ISP can route multiple IP addresses to you, you can use its built-in routing capabilities.  Routing of multiple addresses (usually all or some of a Class C subnet) is not common for cable modem ISPs, and if they will do it, you'll be charged an extra fee. So you'll probably have to use one of the other sharing options.

Advantages

• Free (if you're using NT)

Disadvantages

• Moderate learning curve.
  
• Difficult to set up by non-technical users.

E. Hardware routers/firewalls
Yes, you can actually go buy a dedicated box to handle sharing your network connection. This solution may be suitable more for business applications with many users. Prices, however, are coming within home user range, as "home networking" is recognized as a growing market.

Advantages

• Higher throughput than software + computer solutions
  
• Doesn't require a dedicated computer.
  
• Only need one NIC per computer.
  
• Reliable and runs without much, if any attention, once you set it up.
  
• Provides firewall protection

Disadvantages

• Higher cost than using part of an existing computer.
  
• Still requires configuration.
  
• May not support VPN or tunneling at all, or may have only limited support.

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DSL & Cable Sharing

On the top of this forum, click on Share Tips to see a brief over-view on how to share broadband connection. If that doesn't help, continue on reading. To share the ONE connection (IP Address) from your ISP

A. For external ethernet (RJ45) modems, you have two (2) choices . Get a cable/dsl router (recommended), OR use a sharing software.

B. For internal or USB modems, you can only use a sharing software (in most cases).

I. Using a cable/dsl router

Most popular routers are:

Netgear RT311/RT314 (1-port/4-port)

Linksys BEFSR11/BEFSR41 (1-port/4-port)

SMC SMC7004BR/SMC7008BR (4-port/8-port) with built-in print server

If you already have a HUB, then just get a 1-port router. Still unsure of which router to get? Practically Networking has a comparison chart between different routers. Going wireless? The comparison chart is here.





For 1-port routers, the setup will look like









For 4-port routers (with built-in 4-port switch, the setup will look like











II. Using a sharing software





For internal modems, the setup will look like






and for external modems, the setup will look like






and for USB modems, the setup will look like





Most popular sharing software are:



A. Microsoft Internet Connection Sharing (ICS)

•  For Win98SE(should be the same for WinME)
  


• For Win2K
  

B. Sygate. Some of its features are:

• DMZ Mode Support with ARP Capability
  


• DNS Forwarding Support for Linux/Win2K clients
  


• Multiple DNS Support with Auto-Switching Capabilities
  

C. WinGate. It:

• Allows networked computers to simultaneously share an Internet connection.
  


• Serves as a firewall, prohibiting intruders from accessing your network
  


• Routes Internet traffic and communication between your network and the
  Internet.
  


• Automatically assigns required network addresses to each networked computer
  

Sources: Practically Networked, DSLR, Netgear, Linksys, SMC, Whatis.com

Note: Picture(s) compliments of Greywolf