I am working on a network that consists mainly of 2 stacks of 6 Dell PowerConnect 6224 switches. There are also a few other independent 6224's that connect to the stacks via CAT6 cable. I know when we're having an issue because the lights on the front of the switch will change. Typically they flash fairly slowly and not really in sequence. When they're having an issue, they pulse much more frequently and almost (if not totally) in complete sequence. This seems to be happening on all switches.
It's affecting the network here in that things are running much slower than usual (it's intermittent on some workstations). Mine seems completely unaffected. Others are slow in opening network applications, printing, and even some are slow opening local apps (Word, Excel, PPT).
The switches have spanning tree portfast enabled.
The network had been running fine until last Friday and I honestly can't think of anything that changed.
How can I find the source of this problem and get it corrected?