I've setup VPN connections with different servers today and all worked, in one direction, from VPN client TO VPN SERVER.
BUT I could NOT whatever I tried access ports/services on my 'connected' VPN client's vpn given IP address FROM the VPNSERVER.
In all cases I used Windows Native Client on my Windows 7 PC and I tried various VPN connections to various servers. I tried connecting to a couple different IPSEC L2TP vpn servers and also an SSTP VPN server.
I could access the VPN SERVER and its network from the VPN CLIENT side, but I could never access the VPN Client's vpn given IP from the VPN server side, neither with IPSEC L2tp nor with SSTP regardless of all the routing tricks I tried. ( see VPN SSTP windows client can not ping or connect to VPN server but it can talk to every other PC on the local LAN that VPN server is on )
THE QUESTION:
IS this a PURPOSEFULLY set limitation on native Windows VPN client to protect VPN users? After banging my head all day I came to this conclusion since I was not able to load website or even PING my VPN CLIENT from the VPN SERVER. The other way works fine. My conclusion was that I have to do a Site-to-Site type VPN connection to have 2-way connection between my Windows PC VPN client and the remote vpn server. I assume if what I was trying to do did work, then a lot of VPN users of FREE VPN services could be compromised/hacked/exposed etc so I figured for security reasons it does not allow communication to the VPN client initiated from vpnserver.
BUT after reading this: https://social.technet.microsoft.com/Forums/en-US/1da6fbe1-5263-4097-b87c-6a58afdd15f8/sstp-vpn-back-connections-possible-?forum=forefrontedgeiag
It's claimed there that you CAN connect TO VPN CLIENT from the server? So now I'd like a definitive answer from some networks guru.
So I've just edited this question now to be more specific that I'm only concerned with built-in native Windows VPN client. So, is it possible for a VPNServer administrator to 'initiate' connection and connect to ports on a connected windows VPN client machine? (the VPNserver can be IPsec L2TP or SSTP but client has to be non-server Windows version (Windows 7 Home Premium) using its built-in native Windows VPN client).