Troubleshooting Q&A - April 8, 2004
Internet Connection Sharing and Networking Issues
This week's Q&A looks at when to use - and when not to use - Windows XP's Internet Connection Sharing (ICS) for networking computers, as well as when to go with wireless over wired networks.
By Ron Pacchiano
Q. My roommate and I are having problems trying to share an Internet connection. My roommate has an ADSL modem and a Windows XP Professional computer set up as the host. We bought a Linksys BEFSR41 router and connected the network cable from the DSL modem to the WAN port, then connected both of our computers to LAN ports on the router. We both have Windows XP — she has Professional and I have Home Edition.
After we connect everything, we try to use the Network Setup Wizard but receive an error message that reads, "Cannot complete the Network setup wizard: Other computers cannot connect to the Internet through this computer. In addition to its Internet connection, this computer must have a connection to your network."
A. The fact that you have a Windows XP computer set up as the “Host” system leads me to believe that you’re trying to set up Internet Connection Sharing (ICS) on your systems. If you have a broadband router like the Linksys BEFSR41, then you shouldn’t be using Windows XP’s Internet Connection Sharing (ICS) feature.
ICS is necessary only when you lack a router and instead connect your Internet connection directly to a PC. To properly configure ICS you would need to have two network adapters in the “Host” PC — one to connect to the DSL Modem and the other to connect to your internal network and the machines on it.
When you’re using a router, this isn’t necessary. You simply connect the computers to the router and then the router to the DSL line. The only configuration that needs to take place on the workstations is to verify that the network adapters in both machines are configured to obtain an IP address automatically. Attempting to use both a router and ICS together would explain why you received the error message you did.
From the specs I saw online, the Linksys router has a 4-port switch integrated into it. Just connect each machine’s Ethernet cable directly to the router. If it doesn’t immediately assign your systems IP addresses, it could be because the person who installed your router disabled its DHCP service.
The easiest way to resolve this is to simply reset the router back to the default factory settings. A reset switch can usually be found on the back of the router. Once this has been done, you should be able to connect to the router via a web browser, using the default address and logon information (it’s probably 192.168.0.1 or something similar). Your router’s documentation can provide you with all the information you’ll need to accomplish this.
Most of today’s routers come with a setup wizard that will configure your router to work properly with your DSL line. Once this is done, you should find that both of your computers now have access to the shared Internet connection.
Q. I have a PC running Windows 98 Second Edition and would like to use it to share my cable modem connection with my daughter’s PC. I heard that I could use Microsoft’s Internet Connection Sharing (ICS) program to accomplish this, but can’t seem to figure out how to install it.
Does it come with Windows 98 Second Edition or do I need to download it from Microsoft’s web site? I looked everywhere on my system and just can’t seem to find it. Thanks.
A. The good news is that you don’t need to download Internet Connection Sharing as it is already included with Windows 98 Second Edition. The problem is that it does not get installed by default, which explains why you’re having difficulties locating it.
However, installing it on your system can be accomplished rather easily. All you have to do is go to the Control Panel and select the Add/Remove Programs applet. Once it opens, go to the Windows Setup tab, select Internet Tools, and click Details. Select Internet Connection Sharing and click OK. Click OK again and the system will start installing the new software.
At this point you may be prompted for your Windows 98SE CD, so make sure you have it handy. Once it finishes installing, just reboot your PC and configure the host and client computers to use ICS.
Complete instructions for configuring Internet Connection Sharing for both the host and clients can be found at http://support.microsoft.com/default.aspx?scid=kb;en-us;306126.
One last thing, unless your daughter’s PC is in the same room as yours you might want to consider investing in a low-cost wireless router instead. They are easier to configure and would give you the ability to move the PC around or add new ones without having to trip over wires. Good Luck!
Q. I’m trying to set up a peer-to-peer wireless network between my desktop and laptop computers. One is running Windows 2000 Professional with a Zoom Air card, while the other is running Windows XP Professional with a 3COM card.
Both cards look like they’re configured correctly and are coming up as working in Device Manager, but they can’t seem to communicate with each other. Although an icon in the status bar says I’m connected, I can’t ping from one machine to the other. Any suggestions you have would be greatly appreciated.
A. Before we get started I’d like to point out that in spite of the fact that the status bar says you’re connected, there is a good possibility that your network isn’t configured correctly. All this indicator really signifies is that the card can see the presence of another wireless adapter or access point; it doesn’t mean that it can communicate with it.
Now with that being said, you didn’t provide us with any detailed information on your network configuration, making it impossible for me to tell you exactly what the cause of your problem is. However, there are a number of things you can check to help resolve the problem.
The first thing you should check are the basics. Make sure that both computers are members of the same workgroup. Next, you’ll need to doublecheck your IP settings. In a peer-to-peer environment like this (i.e. one that doesn’t utilize an access point), you should make sure that both PCs are using a static IP address and that they share a common subnet mask.
A typical example for this would be to give PC1 an IP address of 192.168.0.2 and PC2 an IP address of 192.168.0.3. (192.168.0.1 is usually reserved for the Router/Gateway address.) Then each PC would be given a Subnet mask of 255.255.255.0.
With that done we now need to take a look at your wireless settings. Since you’re not using an access point, check and make sure both wireless network cards are in ad-hoc mode rather than infrastructure mode. Most cards default to infrastructure mode, so this can be a common problem.
Now verify that both wireless cards are configured to use the same wireless settings. They should share a common SSID (just like the workgroup name) and they should be transmitting data on the same channel. Adapters made by different vendors sometimes default to different channels, which can prevent communication.
While troubleshooting this problem, you should disable any WEP encryption you currently have enabled. I understand that you want your data to be secure, but WEP can be extremely problematic to configure, particularly from cards made by different vendors. Once you have conductivity between your two systems, then you can worry about getting WEP to function properly.
When you do finally enable it, take your time and ensure that the WEP settings on both cards are set to the same encryption level (64-bit, 128-bit, etc.) and are using identical encryption keys.
If you follow these steps carefully you should find yourself online in no time. Hope this helps!
|Home | Networking | Backgrounders | Internet Sharing | Security | HowTo | Troubleshooting | Reviews | News | About | Jobs | Tools | Forums|