EF3116 different up and down speeds

[RonaldV]

Hi community, this is my first time here.
I have a problem with an EF3116 switch and a specific PC. I have the following configuration : a EF3116 switch with PC1, PC2 and a laptop, connected with short cat5 cables. The combination switch and PC1 is the problem. The ingoing data on PC1 is 10 times faster than the outgoing. So, if I do a ftp ( with a file of about 2G) from PC1 to laptop it takes 200 seconds, the same file from laptop to PC1 takes 18 seconds. The same applies for PC1 -> PC2 which takes 200 seconds, while PC2 -> PC1 tale 18 seconds. PC2 --> laptop is about 17 seconds both way. If I replace the switch with an identical type, all times are 17 or 18 seconds. The same PC1 has the same problem with 2 different ships on which the same type switches are used. I think the switch somehow decides to limit the speed from PC1 but not to PC1, and is related to the MAC address. My question is: How is this problem introduced and how can I solve it. Thanks for any reply. Ronald.

[fox_mulder]

Is there any firewall software installed in those computers?

[RonaldV]

No, on neither PC's or laptop is a firewall installed. We use a minimal Redhat 7.2 Linux configuration. I can get dozens of PC's, installed with the same software (like clones) and the same hardware, that will work with the funny switch. Also, I can get dozens of switches (same type) that will work with the funny PC. Is there a function in the switch, a kind of management mode, with telnet or other, to clean some settings, if present. I know the Catalyst types from Sisco can, and Linksys is Sisco.

[fox_mulder]

this is an unmanaged switch