Hello,

I've got a Proxmox server, and I'm wanting to use an A&A L2TP VPN[0] on
the Proxmox host.

I'm unsure how to set this up in `/etc/network/interfaces`, as I
primarily use NetworkManager on NixOS.

I was thinking of running pfSense/opnSense in a VM, and then connecting
my VMs and LXC containers behind it. The reason I'm using a L2TP VPN is
because the hosting company don't offer IPv6 without a block of IPv4 IPs,
and I think that's overkill. All I need is one IPv6 block and one IPv4
address.

My desired setup would be:

WAN <==> L2TP VPN <==> Proxmox host <==> Firewall VM 
                                          |         |
                                    VMs  <=>       <=> LXC  

[0]: https://www.aa.net.uk/broadband/l2tp-service/

Is this possible?

Best wishes,
--
Dom Rodriguez
GPG Fingerprint: EB0D 45E6 D0DC 1BA1 A2B5  FC24 72DC F123 1E54 BD43