I recently replaced our PowerConnect 2124 switches with new PowerConnect 2848 switches. The 2848s not only allow us to run gigabit but also use managed mode. But some of my users are reporting spotty network connectivity following this upgrade. Seems like they lose connectivty for brief moments. Performance seems spotty at times.

The issue with my building is we have CAT-3 running from the switches to each desktop. Our building is not huge and I found that all desktops were able to run at or near 100 mbps with the CAT-3. Now only those closest to the computer room can run about 100 mbps (tops seem to be 280 mbps). For those who 100 mbps is the top speed, I set each ports on the switch to only advertise 10/100.

Flow Control is enabled for all ports. I do not have Storm Control enabled, as only 1-2% of packets were broadcast or multicast. I have the switches configured so each connects into a "main" switch; they are not chained together.

Not sure if there is really an issue here other than the poor wiring in our building, but these issues didn't seem to happen when I was running the old, dumb 2124 switches. Any suggestions about other settings I could check?