I concur - That was the exact same error I am getting when plugged in via ethernet.
If you go back to @orbistat post on the previous page, and confirm that the when the ethernet is plugged in it is only negotiating at 100M not 1000M as it probably should.
Try unplugging the cable and then back into another port; does this clear the error on the xbox (temporarily as it did with myself).
I've honestly given up plugging it in via ethernet as there has been no traction from support to identify and rectify the issue.
Having previously given the xbox an address reservation both INSIDE and OUTSIDE of DHCP and turning on DMZ for this IP; I still recieved the error.
I would prefer it to be cabled, but just settled with WiFi.