I have tried setting up the ethernet connection many times since I received the GL-RM10. The ethernet on the screen is always yellow. I was not able to set up wired connection. The wifi connection works, but once I inserted the ethernet cable, the connection broke since ethernet received higher priority and either is broken.
I think the only thing you can still try as round for elimination is removing the power wire wait a few seconds or even better powercycle without the power coord in, you could just tab screen for the little power to be gone if any.
Then put in power, if it then still doesn't work, and you also eliminated the other end of the cable not being a issue, my guess point it may be broken.
Did it work before?, you may try also a reset to factory, then you tried basicly anything to troubleshoot the hardware part.
Since I also own the RM10 for me it works fine, but I never configurated wifi, so I can't confirm that maybe that is the issue.
Another thing also comes to mind, also submit logs to support, I thought it was not needed but maybe it is a cable negotiation issue.
I followed the instructions from the customer service. However, the ethernet connection is still broken. I tried: /etc/init.d/S98multi-wan restart, no luck. I am sure my router and ethernet cable are functioning normally after testing them with other devices.
Please try executing the following command: /etc/init.d/S98multi-wan stop. After executing this command, the network icon on the screen will always be displayed in yellow. Please check your actual network status.