Windows Vista : Internet Me (part 1) - Share an Internet Connection

Connecting to the Web is much easier than it used to be, so much so that Windows basically takes this for granted. In fact, I'm going to make this really easy for you: if you have broadband (typically via DSL or cable), and you're not using a router, get one right now and hook it up. Once you set up your router , connect your Vista PC to the router either wirelessly or with a cable, and you're online. That's it.

Now, if have broadband but you can't use a router for some reason, or if you're (gasp) still using dial-up, then you need to configure Vista to connect to the Internet for you. Of course, the procedure depends on the type of connection you're setting up:

Broadband with a static IP address

Set up your Ethernet adapter to use your Internet connection's static IP address.

Broadband with a username and password (PPPoE)

Point-to-Point Protocol over Ethernet (PPPoE) is used to establish temporary, dynamic-IP connections over high-speed Internet connections. If your Internet connection has a dynamic IP address, it means your ISP assigns you a different IP address every time you connect to the Internet. The PPPoE protocol facilitates this connection by sending your username and password to your provider.

Never use the proprietary software provided by your ISP to connect via PPPoE; use the procedure explained here instead for best results.

To set up a PPPoE connection, follow these steps:

1. Open the Network and Sharing Center, and click the Set up a connection or network link on the left.

2. Select Connect to the Internet, and click Next.

3. Click Broadband (PPPoE).

4. Type the User name and Password provided by your ISP, and turn on the Remember this password option.

5. Type a name for the connection (anything you like); click Connect.

Later on, if you need to connect manually or make changes to the connection, use the Network Connections window.

Dial-up (analog modem) connection

Sure it's obsolete, but it's cheap, and if there's no broadband around, it may be your only choice. Here's how to set it up.

1. Open the Network and Sharing Center and click the Set up a connection or network link on the left.

2. Select Set up a dial-up connection, and click Next.

3. Type the Dial-up phone number and User name and Password provided by your ISP, and turn on the Remember this password option.

4. Type a name for the connection (anything you like), and click Create.

5. To connect, click the Manage network connections link, and then double-click your new connection.

See the "Live with PPPoE" sidebar, next, for tips that also apply to dial-up connections.

Live with PPPoE PPPoE can be a pain on a day-to-day basis, mostly because Windows is responsible for the dialing. Here are some ways to make it a little more seamless: Connect on demand. To have Windows connect automatically whenever the connection is needed, open the Network Connections window, right-click the connection icon and select Set as Default Connection. Then, go to Control Panel → Internet Options, choose the Connections tab, and select the Always dial my default connection option. Connect automatically. To have Windows connect automatically when you first start your computer, drag the connection from the Network Connections window to your Startup folder. Connect without asking. To skip the Connect dialog that asks for your username and password each time, open the Network Connections window, right-click the connection, and select Properties (or click the Properties in the Connect window itself). Choose the Options tab, turn off the Prompt for name and password, certificate, etc. option, and click OK. Share a PPPoE connection. Of course, the best way to live with PPPoE is to get a router and let it handle the connection. It'll do a much better job than Windows will, plus it provides a superb firewall and a very convenient means of sharing an Internet connection among several PCs.

1. Share an Internet Connection

When including an Internet connection, you have several choices. The old-school approach, shown in Figure 1, involves a single computer connected directly to the Internet (via broadband, dial-up, or whatever). That PC then serves as a gateway (thanks to Internet Connection Sharing, discussed shortly) and shares the Internet connection with the other computers on the LAN.

Figure 1. A simple workgroup with three computers, one of which has a shared Internet connection

There are several downsides to Internet connection sharing. For one, it can be temperamental and frustrating to set up. Performance and security leave a lot to be desired, and it tends to be slow. Also, one computer (the gateway) must always be on for the others to have Internet access, and that computer must have two network adapters.

The preferred method is to use a wireless router, as shown in Figure 2.

Figure 2. A wireless router not only makes it easy to share an Internet connection, it offers better security and more flexibility than the old-school approach shown in Figure 7-19; all of these computers, wired and wireless, have equal access to the Internet—note the wireless print server

The router is a sole unit (the little box with two antennas in Figure 2) that plays a whole bunch of valuable roles on your network:

• A switch, which connects all the PCs on your network to one another.

• A wireless access point, which serves as a base station for your wireless PCs and devices, and connects them to the rest of your network.

• A router, which bridges your local network to the Internet and provides Internet access to all the computers on your LAN. Plus, if you're using a broadband connection that requires a username and password (e.g., PPPoE), the router will log in automatically for you, and keep you logged in.

• A DHCP server, which automatically assigns IP addresses to computers in your local network (typically starting with 192.168.1.100, where 192.168.1.1 is the router itself), allowing them to coexist peacefully on your network.

• A firewall, preventing any and all communication from the outside world, except that which you specifically allow. (This is done through your router's port-forwarding feature.)

Now, if you don't have a router, the alternative is to use the Internet Connection Sharing (ICS) feature built into Windows, along with a bunch of cables. To get ICS to work, you'll need the following:

• At least two computers, each with an Ethernet adapter properly installed and functioning. ICS can be used with both conventional and wireless networks.

• One of the computers must have an Internet connection properly set up.

• If you're sharing a broadband (DSL or cable) connection, the PC with the Internet connection must have two Ethernet cards installed. See Figure 1, earlier, for a diagram of this setup.

If your Internet connection is accessed through a router or you've allocated multiple IP addresses, you don't need ICS.

The first step in setting up ICS is to configure the host, the computer with the Internet connection that will be shared:

1. In the Network and Sharing Center, click the Manage network connections link. If you haven't already done so, open the Views drop-down and select Details.

2. Here, you should have at least two connections listed: one providing your Internet, and the other providing access to your LAN. If they're not there, your network is not ready. (For clarity, rename the two connections to "Internet Connection" and "Local Area Connection," respectively.)

3. Right-click the connection providing your Internet, and select Properties. This is either an Ethernet adapter plugged into your DSL or cable modem, or, if you're using PPPoE, your broadband connection.

4. This step is optional, but may be required if there are any PCs on your network running Windows 98 or older versions : to set the IP address of the host to 192.168.0.1.

5. Choose the Sharing tab, and turn on the Allow other network users to connect through this computer's Internet connection option, as shown in Figure 3.

   Figure 3. Any Internet connection can be shared with other computers in your workgroup

   

6. Click OK when you're done. Verify that Internet Connection Sharing is enabled; it should say "Enabled, Shared" in the Status column of the Network Connections window.

That's it! The change will take effect immediately, and you won't have to do anything special on the client PCs. Verify that the Internet connection still works on the host by attempting to open a web page, and then try it on each of the clients.

1.1. Fix your shared Internet connection with a new MTU

There are some circumstances when a shared Internet connection doesn't quite work as it's supposed to. The problem, where some web pages load and some do not, affects client computers that access a shared Internet connection facilitated by PPPoE.

Although all web sites will be accessible on the host computer, certain web sites will never load successfully from any of the client machines. If you don't know what "hosts" or "clients" are with regard to ICS, you'll want to review the previous section before you proceed. Note that this applies to Windows' built-in PPPoE support, as well as PPPoE provided by third-party software and even some routers.

The following solution is intended to fix this specific problem.

1. Sit down in front of one of your client machines, and type:

   PING -f -l 1500 192.168.0.1

   
   

   This assumes that 192.168.0.1 is the IP address of the host computer (or router); substitute the correct address if it's different. If you don't know the IP address of the host computer, open a Command Prompt window (cmd.exe) on the host, and type ipconfig at the prompt. (If a router is providing your Internet connection, consult the router documentation for details on obtaining its IP address.)

2. You'll probably get an error message indicating that it must be fragmented. (If not, then this solution doesn't apply to you.) Next, type the following:

   ping -f -l 1492 192.168.0.1

   
   

   If that results in the same error message, try this instead:

   ping -f -l 1480 192.168.0.1

   
   

   If you still get an error, try:

   ping -f -l 1454 192.168.0.1

   
   

   The numbers in each of these examples (1500, 1492, 1480, and 1454) are values for the Maximum Transmission Unit (MTU). Continue issuing this command with lower and lower MTU numbers until you get normal ping responses instead of an error message. The highest MTU value that does not result in an error is the correct one for your network. It's not unheard of for an MTU as low as 576 to be required, although Microsoft recommends no value less than 1,400 for Windows XP.

3. Once you've found an MTU that works for you, open the Registry Editor on the client machine.

4. Expand the branches to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces.

   There should be several subkeys under the Interfaces key; most likely, you'll find three. View each key's contents, and find the one that corresponds to your primary network adapter; it will be the one with more values than the other two, and will have an IP address value set to the IP address of the machine.

5. Once you've found the correct subkey, create a new DWORD value in it by selecting New and then DWORD Value from the Edit menu. Name the value MTU.

6. Double-click the new value, choose the Decimal option, type the MTU value you determined earlier in this procedure, and click OK.

7. Close the Registry Editor when you're done; you'll need to restart Windows for this change take effect.

8. Repeat steps 3–7 for each client machine on your network (but not the host).

In most cases, this should solve the problem. However, on some systems, you may need to set the MTU in another registry location as well. If you've found that a lower MTU value is what you need, but the above procedure didn't work, try this as well:

1. Navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Ndiswan\Parameters\Protocols\0. If any keys in this Registry path aren't there, just create them by going to Edit → New → Key.

2. Once you're in the key, create a new DWORD value called ProtocolType and give it a Decimal value of 2048.

3. Then, create a new DWORD value called PPPProtocolType and give it a Decimal value of 33.

4. Finally, create a new DWORD value called ProtocolMTU and give it a Decimal value of the MTU you determined above.

5. Close the Registry Editor and restart your system when you're done.