nmcli c add type bridge autoconnect yes con-name br0 ifname br0
nmcli c modify br0 bridge.stp no
nmcli c modify br0 ipv4.addresses "xxx.xxx.xxx.142/24" ipv4.method manual
nmcli c modify br0 ipv4.gateway xxx.xxx.xxx.1
nmcli c modify br0 ipv4.dns 127.0.0.1

nmcli c delete System\ eth0
nmcli c add type bridge-slave autoconnect yes con-name System\ eth0 ifname eth0 master br0
systemctl stop NetworkManager; systemctl start NetworkManager