Connect 2 PCs, one has internet via USB-tethering

Support Network
6 
# On Master
nmcli connection modify myconnection ipv4.method shared
sudo systemctl restart NetworkManager
# On Slave
nmcli connection modify myconnection ipv4.method auto
sudo systemctl restart NetworkManager

Re/plugin the Ethernet cable. By default it should get the IP via DHCP automatically on the slave device. Really, just tested. I can ping simply any Domain.