Disclaimer: I have only rudimentary knowledge of VPNs. I would love to learn about them properly, however, at the moment I really need to make stuff work on short notice.

I am trying to set up a ProxMox virtualization platform in an existing network.

The network currently consists of several servers which have VMWare free edition.

There is some sort of VPN defined in switch. In order for VMWare management interface to be accessible, there needs to be ticked a checkbox in the network settings for VPN and entered the VPN id.

I didn't notice any such configuration option during ProxMox installation, so my Proxmox VE on the same physical server, using same manual IP settings (ip/nm/gw), is not accessible.

As I understand I should touch the Proxmox's underlying Debian config in /etc/network/interfaces, but I have no idea, what should I aim for: do I specify the settings for eth0, do I make a virtual interface? How to make it accessible for both ProxMox VE and underlying future VMs? I read the ProxMox installation guide, but unfortunately it presumes better understanding of VPNs than I have.

A config template or similar would be appreciated.

Thanks in advance.