I have now set up the three laptops on an infrastructure network, using the BT Voyager 2000 (ADSL Modem / router / switch et al). Laptop A is "plugged" in via the 1-ethernet port, and the other two (B & C) use Netgear wireless pc cards. Laptop A & B can see each other in network neighborhood, but C is invisible! However, all three can access the Internet with no problems.
There are really two steps to debugging this problem.
1) Verify network connectivity between A and C, and between B and C. Launch a DOS command window and type "ipconfig" to identify the IP address of each PC. Then type "ping " to check connectivity. For example, if A is 192.168.0.2 and C is 192.168.0.3, then from a DOS command windows on A type "ping 192.168.0.3" and look for:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss)
If the result is something like this instead:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss)
then your problem is network connectivity. To debug, look at the adapter Properties panel in laptop C to see if perhaps the Internet Connection Firewall or another firewall program is enabled, blocking incoming traffic. If you don't use dynamic IP addresses, you should also check IP settings on C to be sure you have the right netmask.
2) If all three PCs can ping each other, then start looking for NetBIOS and Network Neighborhood problems. All three PCs should be configured with the same Workgroup Name or all three should be configured with the same Domain Name (one or the other, not a mixture). On Windows XP, names are set from the My Computer / System Information / Computer Name panel. On older Windows operating systems, set the computer's name and workgroup from the Network Control panel. Since you have a home network, you probably should use a Workgroup, not a Domain.
All three PCs must also have the Client for Microsoft Networks enabled; this is done using the network adapter's Properties panel. To verify NetBIOS connectivity, use a DOS command window again to type "nbtstat -A <Ipaddress>" to query the name table of laptop C from either A or B. To get help on using the nbtstat command, type "nbtstat" without any parameters. Finally, although it should not affect seeing shares in Network Neighborhood, accessing shares can be easier if you have the same user (login) account and password on all three PCs.
Member response to this Q&A
- Thanks again for your help. I have resolved the problem, it would appear that it was a firewall issue. We are using Norton Internet Security, and for various reasons needed to uninstall & re-install. Once this was done, all three computers could see each other on the network. Amazing!—Mark
Dig Deeper on Wireless LAN (WLAN)
Related Q&A from Lisa Phifer
As the remote workforce increases, network managers and users might opt to set up two concurrent VPN connections from the same remote device. But ... Continue Reading
Is there a difference between a wireless access point vs. a router? Yes -- while the two wireless devices are related, they meet different needs in a... Continue Reading
Learn the differences between site-to-site VPNs vs. remote-access VPNs and find out about the protocols, benefits and the data security methods used ... Continue Reading