Set ethernet connection MAC address on Fedora/RHEL

• 1 # List eth connection details
  nmcli -t -f NAME,UUID,DEVICE,TYPE c show | awk -F: '{cmd="cat /sys/class/net/"$3"/address 2>/dev/null"; cmd | getline mac; close(cmd); if(mac=="") mac="N/A"; print $0 ":" mac}' | grep 802-3-ethernet
  
• 2 # Assign interface MAC to a variable
  IFACE_MAC=$(ip link show eth0 | awk '/ether/ {print $2}')
  
• 3 # Set eth MAC address
  nmcli c modify ${CONN_NAME} 802-3-ethernet.mac-address ${IFACE_MAC}
  
• N Use empty string "" instead of ${IFACE_MAC} for dynamic asignment.
  

References

• https://networkmanager.dev/docs/api/latest/nm-settings-nmcli.html
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/networking_guide/sec-configuring_ip_networking_with_nmcli
• https://serverfault.com/questions/1006634/nmcli-set-static-ip-address-without-the-dhcp