Debian 12 Ethernet

Open a terminal (Ctrl Alt t) and gGet the device names of the installed Ethernet NIC’s

nmcli device status
Debian 12 Ethernet 1

For me enp5s0 is a PCIe NIC and is connected to the internet so the enp2s0 is the NIC that needs a fixed IP address.

Edit the network configuration file to create a fixed IP address for a Mesa card

sudo nano /etc/network/interfaces

Comment out source /etc/network/interfaces.d/*

# source /etc/network/interfaces.d/*

Add a static IP for the enp2s0 device

auto enp2s0
  iface enp2s0 inet static
Debian 12 Ethernet 2

To save the changes Ctrl x, y, Enter

Reboot the PC to restart the network.

Plug in a Mesa Ethernet card and set the jumpers for and open a terminal (Ctrl Alt t) and test the connection.

Debian 12 Ethernet 3

Ctrl c to stop the ping.