I'm trying to use nmcli to configure a VPN in a remote machine.
The issue is that networking interfaces are google managed.
I've created a VPN connection with
sudo nmcli connection add type vpn vpn-type openvpn ifname test-vpn vpn.data "ca = /home/myuser/ca.vpn.cer, connection-type = password, password-flags = 2, port = 443, proto-tcp = yes, remote = vpn.mycompany.com, username = [email protected]"
But when I try echo "vpn.secrets.password:mypass" > pass.txt; sudo nmcli connection up vpn-mangel-vpnt passwd-file pass.txt it raise Error: Connection activation failed: Could not find source connection.
I've tried to change /etc/NetworkManager/NetworkManager.conf to set ifupdown manage to true:

And adding those lines in /etc/network/interfaces

With that, the VPN connects (Wrong pass fails) but the VPN is not connected to machine network
After many attemps and error, deleting new interfaces that are dynamically created I finally got the vpn connected, and removing folders from run/interfaces I successfully connected to vpn and could check it with a ping. Some minutes later o lost the ssh connection.
I've restarted the machine, but if I connect to the VPN lose the ssh connection.
And I can't replicate in a new instance.
I don't have much idea about VPNs and Interfaces so could someone guide me in what look for?

Google Cloud Virtual Private Cloud (VPC) networks are by default isolated private networking domains. Networks have a global scope and contain regional subnets. VM instances within a VPC network can communicate among themselves using internal IP addresses as long as firewall rules permit. However, no internal IP address communication is allowed between networks, unless you set up mechanisms such as VPC Network Peering or Cloud VPN.