We are now going to a look at how a Proxmox network configuration file works and how we can modify it to adapt to different networking environments. This configuration file is stored at /etc/network/interfaces. Network configuration can be modified both from the GUI and the CLI. Any changes made from the GUI are saved temporarily in /etc/network/interfaces.new. The changes get transferred to /etc/network/interface only after reboot. You can also directly edit the interfaces file at /etc/network/ and activate or deactivate components with #ifup <name> or #ifdown <name> without needing to reboot. All virtual bridges must be configured on all the Proxmox nodes in the cluster. If there is a lot of bridge configurations in the interface file, simply copy them to all nodes and modify only the physical interfaces on each node. The following screenshot is the GUI representation of the configuration file for node pmxvm01:
