Set a Fixed MAC Address on Debian

In this tutorial, you will learn how to set a fixed MAC address for the Ethernet interface on a Debian system using nmcli.

Step 1: List Network Connections

First, list all network connections to identify the connection you want to modify:

nmcli connection show

This command will display a list of all network connections. Note the name of the connection you want to modify.

Step 2: Modify the Connection

Next, modify the connection to set a fixed MAC address. Replace "Connection Name" with the actual name of your connection and "<mac address>" with the desired MAC address:

sudo nmcli connection modify "Connection Name" 802-3-ethernet.cloned-mac-address "<mac address>"
# If it is a Wi-Fi connection, use `wifi.cloned-mac-address permanent`

Step 3: Verify the Change

Verify that the MAC address has been set correctly by running the following command:

nmcli connection show "Connection Name" | grep cloned-mac-address

This should output wifi.cloned-mac-address: "<mac address>" or 802-3-ethernet.cloned-mac-address: "<mac address>", depending on the type of connection.

Step 4: Bring Up the Connection

Finally, bring up the modified connection to apply the changes:

nmcli connection up "Connection Name"

Your network connection should now be using the fixed MAC address you specified.