On Sun, Mar 7, 2021 at 4:25 PM IL Ka <kazakevichilya@gmail.com> wrote:The reason for the two networks is that my modem-router is electrically incompatible with one of my computers.hmm, I never heard about such things)Is your electrical grounding configured correctly?In my country some old apartments do not have third (ground) wire. I've seen a lot of glitches because of that.Have you tried to install an ethernet switch?yes i did, and it did not work --- just the fact that the router was in contact with the incompatible model even through a switch was enough to make it malfunction. :(danYou can connect your modem-router to the ethernet switch, and connect all PCs to this switch. It may help.