Network data corruption

lan

I keep receiving bad data from the net and can't figure out why or even get my machine to realise it. For example, if I try to download a reasonably large file (a few megs), it nearly always comes in corrupt but gives no error when downloading. I've tried this with many files, it's definitely not an isolated bad file/server.

I have a home network and connect to the net through a router, a Netgear DG834G. Other pc's on the network connect fine and I've checked them using the same port/cable. Since they have no problem, I'm pretty sure it's my own machines hardware/software.

Its network card is an nVidia nforce networking controller. It's built onto the motherboard, an Epox 9NPA Ultra + which I have the latest drivers for (I'm running Windows 2000 SP4). Many programs show this error, firefox, internet explorer, azereus, etc. . Transfering data across the network locally doesn't seem to cause the error but I haven't really confirmed that.

No program seems it detect that the data it's downloading is corrupt, I get no errors on downloading files. I thought this was odd because I thought Tcp/Ip had built in error checking. Programs like azereus which preform there own validation do catch the bad data but not during transfer, only by hash after downloading.

I've downloaded a packet sniffer (Ethereal) to see if it finds any problems but as far as I can see it gets no errors, I'm not really sure how to use it. It also reports back the number of transmission errors as 0 but does specify this value comes from the network driver, which could be the problem itself.

I had Zonealarm on the machine but removed it incase it was the cause, I have no firewall on now (except the built in hardware one on the router). The nvidia hardware firewall is turned off.

It looks like a hardware/driver problem but I'm not sure and don't know how it fix it, I'm not that familiar with low level networking. Any help would be greatly appreciated. I can give more details if needed.

Thanks

liamo

The few times I've come across corrupt data on a network it was a dodgy network card to blame.

You'll pick up a cheap network card for about 20 Euro. Disable the on-board NIC and pop in the new card. I'm pretty sure that will solve your problem. If it doesn't, you'll at least have eliminated one possible culprit.

Regards,

Liam

The Insider

Yep sounds like the Nic, replace it and it should fix your problem.