This is the second 256/ 2561w, bought direct from informir. Ethernet connection status down after working ok for 3 weeks. Tried reset to default, updated software. Checked all settings. Won't recognise static IP address. Working ok on wifi but no sound on any media input. Very un reliable devices.
Maybe you unplug the Ethernet too many times, damaging the pins? Or on your LAN network, are you running things like PoE, or Jumbo Frames?
Also, have you tried new Ethernet cable? They do break. I've encountered many failed cables.
Do you have a switch you can plug into your router, and then plug the MAG into the switch instead?
We have to isolate the problem by switching one thing, then testing.
Only test with DHCP - NOT STATIC. Once you get it working with DHCP, then you can change it to static. If it works on DHCP, but not static, then there is a configuration error in the IP address.gateway/DNS.
Also, you need to remove the WiFi network on the MAG and change the IP address/gateway to something that won't work (example. 1.1.1.1). I've noticed that when WiFi is setup, and the Ethernet cable is plugged in, the WiFi still says "UP". We want it to say " Down".
Hope that helps.