Problem solve Get help with specific problems with your technologies, process and projects.

Troubleshooting slow FTP speed over Cisco switches

I have a switched network with Cisco 2950 switches with all ports configured for 100 Mbps full duplex. A 1MB file...

takes 22 seconds when I do a FTP from one machine to an another. Could you let me know what could be the problem. You need to do a little troubleshooting. But first of all don't think that on a 100 Mbps connection you can transfer a 100 Mb file in a second. There are a lot of other factors that are in the picture, i.e., CPU load, memory space, attenuation on wire, other machines taking over the wire, mismatch on duplex and speed at the NIC level, OS of the machines, other applications and many other factors which I may not be knowing.

For your case I would suggest to connect these two machines with a cross cable and check the speed. If it's better than earlier certainly your switch (or any other switch /hub connected between, if at all) is heavily loaded. CPU may not be free. Interface buffers may not be empty. Or connect these two machines on a same VLAN on the switch itself and check. See how many VLAN you have created on the switch, if there is any trunk created or not.

Also check duplex mode and speed of the ports, NIC throughout the path.

This was last published in September 2003

Dig Deeper on Campus area network