Can't get ethernet to connect

[hammerzzz]

My Ethernet connection shows up as red. I've tried a ethernet cable direct from router to iMac and also one via Devolo DLAN 500 to iMac and neither work. Any ideas?
I contacted Apple previously and they suggested a reinstall which i did today and still no change. On Monterey 12.5. 2019 iMac

 

[Fishrrman]

Thoughts in no particular order...

Can you connect via wifi? (even a slow connection, the point is simply "to connect")

Did you try the following?
a. Open the "network" pref pane
b. On the left, click the ethernet connection ONE TIME to select it
c. Down below on the left, click the "-" sign to DELETE the ethernet connection.
d. Close System Preferences and REBOOT
e. Re-open the network pref pane, and click the "+" sign on the lower left to ADD a new connection.
f. Make it ethernet.
g. Does that work?
(no promises, just something to try)

 

[hammerzzz]

wifi is fine. done the rest and still no joy.

 

[svenmany]

Are you using DHCP and are you getting an IP address? If yes and no, respectively, try setting a manual IP address as an experiment.

 

[Brian33]

On Monterey 12.5. 2019 iMac

I don't think a 2019 could come with Monterey, so you were running, maybe, Big Sur before? Did the Ethernet connection work then? Did it only stop working when you upgraded to Monterey?

 

[Nermal]

Can you boot into Internet Recovery via cable? That'll take your currently-installed OS out of the equation. Does the light on the switch at the other end come on when the cable's connected?