I have three network switches, all gigabit, from DLink and TPLink:
- 1x 4-port
- 2x 8-port
Connecting to these are 5 laptops and 2 desktops, all with gigabit NICs:
- 4 Realtek
- 1 Intel
- 1 AMD
- 1 unknown
The network has 4 45' runs and 4 60' runs.
All computers will only connect at gigabit speed when the runs are less than 30'.
I've tried 4 different cable brands, all riser-rated Cat 5e from Hitachi, Frisby, Webtrack, and one unknown brand. I have re-tipped the cables several times. I've used keystone jakcs at both ends with pre-made cables. I have used a 24-port patch panel with pre-made cables at the ends. I have tried PC-to-PC. I've played with the hardware settings.
I have not yet tried Cat 6. I've ordered it but the shipment is delayed currently.
I was able nail down 30' as the success point by starting with a 75' cable, testing it, and then cutting 5' off the end until the the systems connected at gigabit.
The problem is that none of my runs are shorter than 45' and so obviously 30' won't work in the environment.
Does anybody have any ideas as to what may be causing this issue?