Self Assigned Ip Address. You can use to solve the self-assigned IP address issue on your Mac running macOS High Sierra, macOS Mojave and the latest macOS Catalina. The only thing that fixes it every time is.
Nothing else I found online worked for me, but this finally fixed my problem. I had this issue for months and was only able to go online via ethernet. Fix Self-Assigned IP Address Issue on Mac.
Luckily, there is an easy solution.
If a third device The MacBook shows the physical ethernet connection as up but the IP address is self-assigned and not correct.
If your DHCP server uses that address then. Self IP Address is also used to send monitor probes to the group of servers in that VLAN. I had this issue for months and was only able to go online via ethernet.