Weird slow network performance...

[syee]

I have a weird problem that has had me baffled for the last few days...

I have a VLAN where I have 4 servers situated. 3 of the servers appear to work fine on the network. I can browse the internet, connect to remote computers, etc with no problem. Speed seems reasonable when connecting to ther machines. However, I have this one particular machine that seems to be SUPER slow.

I'll start with the specs of this machine to see if it makes any difference.

*Pentium 233 SBC (single board computer) with on board Macronix 987x LAN controller
*256MB RAM
*Running Windows NT 4.0 SP6a and our custom recording software.

I know the CPU is antiquated.

I have another box on the same VLAN that has similar specs that is working fine.

With this particular machine, I've tried to run a netstat -a to see what connections it is trying to establish in the hopes of uncovering a trojan or some kind of virus like activity on specific ports. Everything that shows up shows the destination as itself, and I don't see any mysterious ports that are out of the ordinary. However, whenever I try connect to the Internet, it is SLOW (to give you an idea, I have been trying to run a Windows Update on the machine, and it has only downloaded 400k of data over the last 4 hours). Another machine on the same VLAN was able to download the same update within 5 minutes.

I changed out the CPU thinking it might be the NIC causing the problems...however, it didn't really resolve the problem. I also reinstalled the OS on the machine to eliminate any possibility of a virus or trojan or corruption being the cause.

All these changes hasn't done any good and the connection is still slow. Even a local connection from my PC to this box yeilds slow speeds. I am trying to file transfer files to this box, and the transfer speed shows 68 bytes/sec (this machine is about 200ft away from where I am). The network parameters are the same as the working machines (subnet mask, gateway, DNS, WINS)...I just can't figure out what is causing the general slowness...anyone have any ideas?

 

[Slowlearner]

Have you tried changing the NIC? It may be an old 10Base T, research the model/make. If its the current standard 10/100, make sure its set for full duplex. Next checking the cabling - is it all in good shape? BTW what kind of cables do you have ?

 

[syee]

The NIC is built into the CPU board. I just changed out the entire board today. At least now, a ping doesn't result in any packet loss (it was getting 25-50% packet loss before).

It's a 10/100 NIC, but I didn't check for full duplex. It's set to autodetect. I'll try force it to full and see if that helps. The cabling is Cat 5e. I'm going to try switch out the cables with one of the known good machines to see if that helps when I get back to the office on Monday.

 

[JeffMD]

did you try connecting to a different port on the switch? You may have gotten a bad port. I've had ports die on my routers and swithes before.