I have a very strange issue with my home network.
I have a router (TP-Link Archer C7) that brings me an internet connection by ethernet and WIFI. It works well until my Mac, which is plugged directly by ethernet cable to the router, goes into sleeping mode. Then I have no internet connection on all my devices connected by WIFI. If I turn on my Mac back on, the internet connection comes back... I don't have any idea what can cause this issue. I have barely learned some basics about network and I can't figure it out with my knowledge...
112 Answers
SOLVED. I had the same issue after connecting my mac laptop to a Dell USB-C Hub Monitor - U2722DE, from which the Ethernet cable was connected to a network switch. My entire network was stopping working soon after my mac laptop was going into sleep mode (before I was using a different docking solution and never had any problem).
To fix, go to System Preferences --> Battery --> Power adapter and disable "Wake for network access". In this way the network on the laptop will not be active, and it will not cause any issue on the rest of the network. However, if you need to have your network active while in sleep mode, this will not be a viable solution, and I suggest using a different way to connect the laptop to the network
Not sure if this will work, but my intuition tells me that the Mac is trying to override your router as the primary DHCP server. If you don't recall setting that up yourself in any application, the most likely place the DHCP server would be enabled in System Preferences.
Try going to > System Preferences > Sharing. Click on Internet Sharing in the column on the left, and make sure that the checkbox next to it is unchecked - marked 1 in the screenshot. Also make sure that all the checkboxes on the right column are unchecked - 2 in the screenshot. If that's all done, you should see a red dot and "Internet Sharing: Off" where I've marked 3. If that red dot was green when you started, that probably means that we've found the culprit.
