How would you log/monitor vpn traffic on your own custom VPN? I don’t think this was covered in the course unless I overlooked it.
It depends how you mean.
Do you mean on the wire? - This would be through protocol analyses, or on routers and firewalls. This is covered in volume 2.
Do you mean on a VPN client? This would depend on the client. If you take for example airVPNs client there is simply an option to switch logging on
Do you mean on the VPN server? This would depend on the server. With OpenVPN you switch on logging
Hope that helps.