I am inside an enterprise network, and connecting a P2P VPN to an Azure VPN gateway. With that VPN connection up I can RDP to a jump server.
I want to do a port scan, indicated by the red arrow. The ports should appear to be closed when scanned from any other place than the jump host (due to firewall rules, in Azure - Network Security Group rules).
I want to test that nodes connected to the VPN gateway should be able to reach the jump host, but nothing else. The reason we want to test this is that we are using Azure technology that is new to us (firewall rules implemented by Network Security Groups). It's a proof of concept project.
What I discovered is that I cannot scan these directly with nmap from my local machine, because the VPN is treated like a PPP connection/dialup interface in windows. E.g. see http://seclists.org/nmap-dev/2006/q3/438.
I am looking for input suggestions on how to proceed.