diff --git a/sources/tech/20180128 How to add network bridge with nmcli (NetworkManager) on Linux.md b/sources/tech/20180128 How to add network bridge with nmcli (NetworkManager) on Linux.md new file mode 100644 index 0000000000..bf7772ef1a --- /dev/null +++ b/sources/tech/20180128 How to add network bridge with nmcli (NetworkManager) on Linux.md @@ -0,0 +1,146 @@ +How to add network bridge with nmcli (NetworkManager) on Linux +====== + +I am using Debian Linux 9 "stretch" on the desktop. I would like to create network bridge with NetworkManager. But, I am unable to find the option to add br0. How can I create or add network bridge with nmcli for NetworkManager on Linux? + +A bridge is nothing but a device which joins two local networks into one network. It works at the data link layer, i.e., layer 2 of the OSI model. Network bridge often used with virtualization and other software. Disabling NetworkManager for a simple bridge especially on Linux Laptop/desktop doesn't make any sense. The nmcli tool can create Persistent bridge configuration without editing any files. **This page shows how to create a bridge interface using the Network Manager command line tool called nmcli**. + + + +### How to create/add network bridge with nmcli + +The procedure to add a bridge interface on Linux is as follows when you want to use Network Manager: + +1. Open the Terminal app +2. Get info about the current connection: +``` +nmcli con show +``` +3. Add a new bridge: +``` +nmcli con add type bridge ifname br0 +``` +4. Create a slave interface: +``` +nmcli con add type bridge-slave ifname eno1 master br0 +``` +5. Turn on br0: +``` +nmcli con up br0 +``` + +Let us see how to create a bridge, named br0 in details. + +### Get current network config + +You can view connection from the Network Manager GUI in settings: +[![Getting Network Info on Linux][1]][1] +Another option is to type the following command: +``` +$ nmcli con show +$ nmcli connection show --active +``` +[![View the connections with nmcli][2]][2] +I have a "Wired connection 1" which uses the eno1 Ethernet interface. My system has a VPN interface too. I am going to setup a bridge interface named br0 and add, (or enslave) an interface to eno1. + +### How to create a bridge, named br0 + +``` +$ sudo nmcli con add ifname br0 type bridge con-name br0 +$ sudo nmcli con add type bridge-slave ifname eno1 master br0 +$ nmcli connection show +``` +[![Create bridge interface using nmcli on Linux][3]][3] +You can disable STP too: +``` +$ sudo nmcli con modify br0 bridge.stp no +$ nmcli con show +$ nmcli -f bridge con show br0 +``` +The last command shows the bridge settings including disabled STP: +``` +bridge.mac-address: -- +bridge.stp: no +bridge.priority: 32768 +bridge.forward-delay: 15 +bridge.hello-time: 2 +bridge.max-age: 20 +bridge.ageing-time: 300 +bridge.multicast-snooping: yes +``` + + +### How to turn on bridge interface + +You must turn off "Wired connection 1" and turn on br0: +``` +$ sudo nmcli con down "Wired connection 1" +$ sudo nmcli con up br0 +$ nmcli con show +``` +Use [ip command][4] to view the IP settings: +``` +$ ip a s +$ ip a s br0 +``` +[![Build a network bridge with nmcli on Linux][5]][5] + +### Optional: How to use br0 with KVM + +Now you can connect VMs (virtual machine) created with KVM/VirtualBox/VMware workstation to a network directly without using NAT. Create a file named br0.xml for KVM using vi command or [cat command][6]: +`$ cat /tmp/br0.xml` +Append the following code: +``` + + br0 + + + +``` + +Run virsh command as follows: +``` +# virsh net-define /tmp/br0.xml +# virsh net-start br0 +# virsh net-autostart br0 +# virsh net-list --all +``` +Sample outputs: +``` + Name State Autostart Persistent +---------------------------------------------------------- + br0 active yes yes + default inactive no yes +``` + + +For more info read the following man page: +``` +$ man ip +$ man nmcli +``` + +### about the author + +The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on [Twitter][7], [Facebook][8], [Google+][9]. + +-------------------------------------------------------------------------------- + +via: https://www.cyberciti.biz/faq/how-to-add-network-bridge-with-nmcli-networkmanager-on-linux/ + +作者：[Vivek Gite][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.cyberciti.biz +[1]:https://www.cyberciti.biz/media/new/faq/2018/01/Getting-Network-Info-on-Linux.jpg +[2]:https://www.cyberciti.biz/media/new/faq/2018/01/View-the-connections-with-nmcli.jpg +[3]:https://www.cyberciti.biz/media/new/faq/2018/01/Create-bridge-interface-using-nmcli-on-Linux.jpg +[4]:https://www.cyberciti.biz/faq/linux-ip-command-examples-usage-syntax/ (See Linux/Unix ip command examples for more info) +[5]:https://www.cyberciti.biz/media/new/faq/2018/01/Build-a-network-bridge-with-nmcli-on-Linux.jpg +[6]:https://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-cat-command-examples/ (See Linux/Unix cat command examples for more info) +[7]:https://twitter.com/nixcraft +[8]:https://facebook.com/nixcraft +[9]:https://plus.google.com/+CybercitiBiz