After the bridge is configured with Mac, bridge is automatically disabled.
Each time (including restart), you need to manually execute the following command to enable:
```
sudo ifconfig br1 up
```
The command to configure the MAC address is as follows:
```
set interfaces bridge br1 mac <mac-address>
```
Usually, the bridge will automatically select the MAC of the smallest port in the port list as its MAC address. However, when I try to specify a non-existent MAC address as the bridge Mac, it will automatically shut down when I execute commit, although communication can be restored by manually executing the up command. I don't know that this is the design situation, and I have not tested whether the same situation will happen when the MAC in the specified port list is the bridge Mac. However, if this situation will cause the bridge to work abnormally or possibly stop, then at least a warning should be output during commit instead of disable directly.