Question: 2013 iMac ONLY negotiates 100 Mbps
I have a Late 2013 iMac running High Sierra 10.13.2 that will only negotiate 100 Mbps on the built in ethernet port. It works fine at 100 Mbps. I would use the thunderbolt adapter, but I am using both ports for additional monitors.
Below are my completed trouble shooting steps.
1. Cable. I connected the cable to the same switch port with a thunderbolt adapter and it negotiated 1000 Mbps on my iMac.
2. Switch. I used the same port, cable, and thunderbolt adapter on my MacBook Pro and it too negotiated 1000 Mbps.
Is there any remedy to this nightmare?
iMac, macOS High Sierra (10.13.2)