9.2. Using the NetworkManager Command Line Tool, nmcli To create a bridge, named bridge-br0 , issue a command as follows as root : If no interface name is specified, the name will default to bridge , bridge-1 , bridge-2 , and so on. To view the connections, issue the following command: Spanning tree protocol ( STP ) is enabled by default. The values used are from the IEEE 802.1D-1998 standard. To disable STP for this bridge, issue a command as follows as root : To re-enable 802.1D STP for this bridge, issue a command as follows as root : The default bridge priority for 802.1D STP is 32768 . The lower number is preferred in root bridge selection. For example, a bridge with priority of 28672 would be selected as the root bridge in preference to a bridge with priority value of 32768 (the default). To create a bridge with a non-default value, issue a command as follows: The allowed values are in the range 0 to 65535 . To change the bridge priority of an existing bridge to a non-default value, issue a command in the following format: The allowed values are in the range 0 to 65535 . To configure a bridge connection to forward group addresses in the range from 01:80:C2:00:00:00 to 01:80:C2:00:00:0F , change the group-forward-mask property. This property is a mask of 16 bits. Each bit corresponds to a group address in the above-mentioned range that must be forwarded. For example: Important The group-forward-mask property cannot have any of the 0 , 1 , 2 bits set to 1 because those addresses are used for Spanning tree protocol (STP), Link Aggregation Control Protocol (LACP) and Ethernet MAC pause frames. To view the bridge settings, issue the following command: Further options for 802.1D STP are listed in the bridge section of the nmcli(1) man page. To add, or assign an interface, for example enp1s0 , to the bridge bridge-br0 , issue a command as follows: To assign an existing connection to a bridge, proceed as follows: Change its controller and port-type properties. For example to assign an existing VLAN connection named vlan100 : Reactivate the connection to apply the changes: To change a value using interactive mode, issue the following command: You will be placed at the nmcli prompt. See Section 3.3, "Configuring IP Networking with nmcli" for an introduction to nmcli .

Commands:
~]# nmcli con add type bridge ifname br0 Connection 'bridge-br0' (6ad5bba6-98a0-4f20-839d-c997ba7668ad) successfully added.
~]USD nmcli con show NAME UUID TYPE DEVICE bridge-br0 79cf6a3e-0310-4a78-b759-bda1cc3eef8d bridge br0 enp1s0 4d5c449a-a6c5-451c-8206-3c9a4ec88bca 802-3-ethernet enp1s0
~]# nmcli con modify bridge-br0 bridge.stp no
~]# nmcli con modify bridge-br0 bridge.stp yes
~]USD nmcli con add type bridge ifname br5 stp yes priority 28672 Connection 'bridge-br5' (86b83ad3-b466-4795-aeb6-4a66eb1856c7) successfully added.
~]USD nmcli connection modify bridge-br5 bridge.priority 36864
~]USD nmcli connection modify bridge-br5 bridge.group-forward-mask 8
~]USD nmcli -f bridge con show bridge-br0
~]USD nmcli con add type ethernet ifname enp1s0 master bridge-br0 Connection 'bridge-slave-enp1s0' (70ffae80-7428-4d9c-8cbd-2e35de72476e) successfully added.
~]USD nmcli connection modify vlan100 master bridge-br0 slave-type bridge
~]USD nmcli connection up vlan100
~]USD nmcli connection edit bridge-br0
nmcli> set bridge.priority 4096 nmcli> save Connection 'bridge-br0' (79cf6a3e-0310-4a78-b759-bda1cc3eef8d) successfully saved. nmcli> quit