This week while going through TechRepublic's Technical Q&A forum, I found an interesting post from member ChuukAG who is having trouble with a three-machine, Windows 2000 peer-to-peer network. "The NICs and cables are working okay, but I cannot see other computers in the neighborhood," ChuukAG wrote, "I ping each machine from the other and no response."
According to ChuukAG, each PC on the network is using the 192.168.100.x IP address range and is subnetted as 255.255.255.0. The selected address range and subnet mask should work fine for the task at hand. However, there are several problems that could be preventing the PCs from talking to each other. Let's take a look.
Check the hardware first
In a situation like this, the first thing that you need to do is to verify that there isn’t a hardware problem. All of the NICs must be working. Furthermore, the correct cable types must be used, and the cables should be connected to a hub. ChuukAG should not use crossover cables, because these cables are used to directly connect two PCs on a peer-to-peer network.
Give me a ping
Once you determine that no hardware problems exist, test communications between the machines. ChuukAG reported that he was unable to ping from one PC to another. I would recommend pinging by IP address. If TCP/IP is configured correctly but you are unable to ping by IP address, it could mean a hardware problem still exists or that the NIC’s driver isn’t working correctly. If after checking these factors you are still unable to ping by IP address, I would suggest changing the 192.168.100.x address range to something more common, like 192.168.0.x. The subnet mask for this range should be 255.255.255.0.
What's in a name?
If you're able to ping by IP address, communications are working correctly. However, you may still not be able to browse the network neighborhood because of name resolution problems. Normally, when TCP/IP is used on a network, a DNS or a WINS server is used to resolve host names to IP addresses. If you're building a small peer-to-peer network consisting entirely of workstations, setting up one of these servers may not be an option.
In such a case, you might consider installing the NetBEUI protocol. Normally, I don’t advise running NetBEUI, especially along side of TCP/IP, because of the amount of network traffic that NetBEUI generates. However, for small, peer-to-peer networks, the NetBEUI protocol is ideal and will solve name resolution problems.
Check for software conflicts
If none of these techniques get the job done, it could be that some software mechanism is interfering with communications. I would recommend checking the software running on each PC, temporarily disabling any personal firewall software, and checking to see if the problem goes away after doing so. For more information on resolving network connectivity problems, download TechRepublic's network access troubleshooting decision tree.