Did your current configuration EVER work? If it has been
working fine for months, and then goes nuts, something has
changed in the configuration or possibly an electronic
fault has popped up.
You will have to isolate the problem further. Is it all
PC's on one switch that have problems, or is it all of them? Can you switch off all PC's execept one, and then
turn them back on one by one to see if a "babbling" network
card in a PC is causing the problem?
papa4