Linux Mint 19 EthernetΒΆ

Configure the network adapter to work with an ethernet card

To find the ethernet adapter name in a terminal

ip link show or ip a

To setup a static IP address edit /etc/network/interfaces file

sudo nano /etc/network/interfaces

auto enp0s25 << change to match your interface name
        iface enp0s25 inet static

shutdown and install a second LAN card if you need to connect to the internet