Windows 7 : Configuring Your LAN (part 3) - Connection Sharing Router with a Broadband Connection, Cable Internet with Multiple Computers

3. Connection Sharing Router with a Broadband Connection

Your router’s manufacturer will provide instructions for installing and configuring it. If you’re using cable or DSL Internet service, you’ll connect your broadband modem to the router using a short Ethernet patch cable. Then you’ll connect the router to your LAN using one of the two methods shown in Figure 5.

If you connect your router to a separate switch (or hub), be sure that the link indicators come on at both the switch and the router. If they don’t, you might need to move the switch end of the cable from a regular port to an uplink port or vice versa.

You then configure the router, telling it how to contact your ISP and what range of IP addresses to serve up to your LAN. Every device will use a different procedure, so you will have to follow the manufacturer’s instructions.

If your ISP uses PPPoE to establish a connection, you need to enable PPPoE and store your logon and password in the router. Most DSL service works this way. If your DSL provider does use PPPoE, you should enable the router’s auto-sign-on feature, and you can optionally set up a “keepalive” value that will tell the modem to periodically send network traffic even if you don’t, to keep your connection active all the time. (This might violate your service agreement with the DSL provider—better check before you do this.)

If you use cable Internet service and your ISP didn’t provide you with a special hostname that you had to give to your computer, your ISP probably identifies you by your network adapter’s MAC (hardware) address. You might find that your Internet connection won’t work when you set up the router. One of your router’s setup pages should show you its MAC address. You can either call your ISP’s customer service line and tell them that this is your new adapter’s MAC address, or configure the router to “clone” your computer’s MAC address—that is, copy the address from the computer you originally used to set up your cable connection. Your router’s setup manual should tell you how to do this.

You might also opt for even better hacker protection by having your router filter (block) Microsoft file and printer sharing data. This is usually done on an advanced setup screen labeled

Using Universal Plug and Play

If you use a hardware connection-sharing router, you might want to consider enabling a feature called Universal Plug and Play (UPnP). UPnP provides a way for software running on your computer to communicate with the router. Specifically, UPnP provides a means for the following:

• The router to tell software on your computer that it is separated from the Internet by NAT. This may let some software—the video and audio parts of most instant messaging programs, in particular—have a better chance of working.

• Software running on the network to tell the router to forward expected incoming connections to the correct computer. Again, Windows Live Messenger is a good example. When the computer on the other end of the connection starts sending data, the router would not know to send it to your computer. UPnP lets UPnP-aware application programs automatically set up forwarding in the router.

• Other types of as-yet-undeveloped hardware devices to announce their presence on the network so that Windows can automatically take advantage of the services they provide.

To use UPnP, you must enable the feature in your router. It’s usually disabled by default. If your router doesn’t currently support UPnP, you might have to download and install a firmware upgrade from the manufacturer. Most routers now do support UPnP.

4. Cable Internet with Multiple Computers

In this configuration, follow your ISP’s instructions for setting up each computer separately. The only unusual thing here is that the computers plug in to a switch or hub, and the switch or hub plugs in to the cable modem—otherwise, each computer is set up exactly as if it was a separate, standalone computer with cable Internet service.

To verify that the network location is set to Public Network on Windows 7, follow these steps:

If you later decide that you want to use file and printer sharing, do not simply set the network location to Home or Work and enable file and printer sharing. Instead, set up a shared connection using scheme B or C.

5. Routed Service Using a Router

Some ISPs will sell you service that provides multiple, fixed IP addresses. This is the case for Frame Relay service and, in some cases, higher-priced business-class DSL service. You should really have a good reason for going this way, beyond just wanting to connect multiple computers—it’s not as secure as a single shared connection. Good reasons might be that you want the reliability of Frame Relay service or you need fixed IP addresses to host web, email, or other Internet-based services on several different computers.

For this type of service, if you are using a cable, DSL, satellite, or Frame Relay modem with a built-in router, your ISP will help you configure your network. In this setup, you will be provided with a fixed list of IP addresses, which you’ll have to parcel out to your computers. Your ISP should help you install all of this, but I can give you some pointers.

First of all, it is absolutely essential that your router be set up to protect your network. You must ensure that at least these three items are taken care of:

Second, either your ISP will set up your router to automatically assign network addresses using DHCP, or you will have to manually set up a fixed IP address for each computer, using the IP address, network mask, gateway address, and DNS server addresses supplied by your ISP.

If you will be making the settings manually, make a list of the names of each of your computers and the IP addresses you want to assign. Follow these steps on each computer that is to get manual settings: