# Add a bridge interface to Ubuntu desktop using nmcli
Had to do this for some advanced networking with KVM, and couldn't figure out how to do it using the Nework Manager gui.
Did find an article later that showed how to do it with nmtui, but it's so much easier to record what you did when using
the cli.

Note: I now set ```net.ifnames=0``` in grub for all my machines, to ensure my device names are "predictable" (so the first ethernet device will be "eth0" and not "ens1", "eno1 or anything else).

To see what everything looks like before starting:

```
$ nmcli con show
```
I renamed "Wired Connection 1' to the name of my physical interface:

```
$ sudo nmcli con mod 'Wired Connection 1' con-name eth0
```
So let's start out by creating the bridge itself:

```
$ nmcli con add ifname br0 type bridge con-name br0
```
Now add the physical interface as its slave:

```
$ nmcli con add type bridge-slave ifname eth0 master br0
```
Disable STP:

```
$ nmcli con mod br0 bridge.stp no
```
Now down the physical interface:

```
$ nmcli con down eth0
```
For this machine I want a static address:
```
$ nmcli con mod br0 ipv4.addresses 10.1.1.16/24
$ nmcli con mod br0 ipv4.gateway 10.1.1.1
$ nmcli con mod br0 ipv4.dns '10.1.1.1,8.8.8.8,8.8.4.4'
```
Don't forget to set your search domain:
```
$ nmcli con mod br0 ipv4.dns-search 'example.com'
```
Finally tell Network Manager this will be a manual connection:
```
$ nmcli con mod br0 ipv4.method manual
```
Finally, bring up the new bridge interface:
```
$ nmcli con up br0
```
Run ```nmcli device show``` to confirm your changes, and then restart NetworkManager (```sudo systemctl restart NetworkManager.service```)
to make sure the configuration sticks.