Fundamental problem with 10/100 base-T

[JohnE]

Okay, a short history lesson. Prior to buying my latest motherboard I used a Belkin wireless LAN to connect my 2 machines in a peer-to-peer network (1 x desktop machine, 1 x laptop). When I bought the new motherboard (about 4 months ago) I carried on using it successfully, even though both my machines now have onboard 10/100 base-T. Eventually I overcame my laziness and went to my local computer shop and bought a crossover cable which I installed after removing the wireless LAN. It worked brilliantly and was wonderfully fast - until I switched the machines off and tried to turn them on again the following morning. The machines turn on alright, but the cable network just refuses to work.

I've figured out that it must be a really fundamental problem because I can't even ping one computer from the other. The hardware appears to be working and both machines do notice if the cable is removed, for example. Both machines claim that the link is working at 100mbits/s but absolutely no communication takes place. Sometimes I got occasional problems like this with the old wireless LAN and I found that if I set the IP addresses to 10.0.0.1 and 10.0.0.2 respectively, that would usually start it working again and I could then change the settings - however, that's not working with the cable setup.

Both machines use Windows XP Home Edition and I've even tried the setup wizard (which fails to complete on both machines). The really annoying thing is that it worked perfectly for the first day! I've tried re-installing the wireless LAN (which still works) but nothing seems to bring the cable network to life.

There's a possible clue in all of this. If I run 'ipconfig /renew' from the command line, both machines report "Unable to contact your DCHP server". Does that mean anything or isn't it relevant in peer-to-peer networking?

I've been plugging away at this for two whole days without success. Please help someone....

[Uranium-235]

your IP addresses need to be set statically. There is no DHCP daemon built into XP Home so don't bother with ipconfig.

The wireless lan was using DHCP. Since you no longer use it, the computers have no way of optaining an IP address so you have to set them manually

Set one machines IP address to 192.168.0.1 and the other to 192.168.0.2. Both should have a Subnet mask of 255.255.255.0 and set the workgroup name to anything you want just as long as both machines match. .

[JohnE]

Thanks to you both for the suggestions. In fact I'd already tried the 192.168.X.X addresses before setting them to 10.0.0.1 and 10.0.0.2. I've used subnet masks of 255.0.0.0 and 255.255.255.0 but still no joy.

The actual hardware link seems to be working. For example, I can set the link speed on either machine (to 10Mb/s or 100Mb/s) and both machines report the correct link speed. Also, if I remove the cable, both machines report the cable as unplugged and both of them respond when the cable is plugged back in again. The only oddity which I discovered after my original post is that if I ping machine 1 from machine 2, the 'transmit' icon on machine 2's system tray will immediately light up. However, nothing at all happens if I try to ping machine 2 from machine 1. It's as though the hardware is working but somehow, the software can't communicate with it.

I found some info on another forum from someone who described the same problem and said he had fixed it by uninstalling TCP/IP and then re-installing it. Althouh he described a procedure for doing this, he reckons that it won't work for Windows XP. Do either of you know how to do this for XP?

Thanks,

John

[JohnE]

Woohoo! - I got it working again. This makes no sense whatever to me but I'll post it and see if it makes any sense to you guys....

My PC actually has 3 x primary partitions, allowing me to boot into Windows XP, 2000 or 98 respectively. After removing the Belkin software (which was installed on all three) none of these OS's could communicate with my laptop (at least, not using the 10/100 Base-T Ethernet) as I described.

By a stroke of luck, I'd had the foresight to back-up my Win2k partition immediately before removing the Belkin stuff. This morning (after days of frustration) I bit the bullet and restored the old Win2k partition to see what would happen. Guess what? All THREE OS's now have their TCP/IP working again and I can ping away merrily and even communicate via my Ethernet cable LAN again. The strange thing is that I didn't do anything to the other 2 partitions - only the Win2k one. So why have the others mysteriously sprung into life?

I don't understand it but I'm glad it happened !!

Cheers,

John

It's FM.