I try to use a RPi4 B as a server (to setup netxcloud, PiHole, etc). To do this I connect it to the modem via ethernet connection as showed in this picture :
At first it works, the RPi is detected as router by the modem :
But then after some hours, the RPi seems to no be detected by the modem and the ethernet LEDs are turned off :
I need to reboot the RPi4 to get the ethernet reconnected to the modem.
I don't know much about network so I don't know if the problem is linked with the RPi itself (maybe the ethernet goes to a sleep mode after a certain time) or the modem.
Some of you have any idea how I could solve this problem so that I can run my RPi4 24/24h ?