So this is how you build a network bridge, configured to use DHCP, using network manager.

nmcli con show This lists all available connections. I used it to identify the physical connection enps30

nmcli con add ifname <bridge name> type bridge con-name <bridge name> This command adds a new connection, type bridge, with name <bridge name>

You then use nmcli con add type bridge-slave ifname <connection name> master <bridge name> to add the physical connection <connection name> to the bridge <bridge name>

nmcli con mod <bridge name> bridge.stp no Turns off STP. Don’t ask questions

nmcli con down <connection name> Takes down <connection name>,but can be any physical or logical network connection.

nmcli con up <bridge name> brings up <bridge name>, but can be any physical or logical network connection.