I was changing some things in a server room this week:
Using cat5e cable and these ends
However, we experienced a network slowdown the following day because some of the servers turned their NIC down to 100MB because the new cable could not handle 1 gig...
Why did this new cable not handle 1 gig? It was only some of them too... I did run the cable on a handheld tester to verify it was okay before connecting it but the reader does not give speed rating.. simply a yes or no.
Any ideas? Simply bad terminating?