[Mashiro]

So you want to build a VPN server. Why not say it from the start, though? Admittedly I have never installed a pure IPSec VPN server myself. So I can only point you to a guide that I know about that was written by a very clever network and system administrator from LET.

Here you go: https://raymii.org/s/tutorials/IPSEC_vpn...tOS_7.html

It is very detailed. Give it a try. He also has links to different various other VPN guides.

Alternatively I could provide you a working guide a multi VPN protocol suite solution if you are interested (it includes a SSL VPN, L2TP with IPSec and OpenVPN in one server).

Be aware that certain VPN technologies may not work on OpenVZ VPSs due to more complex firewall needs that aren't supported by OpenVZ inside OpenVZ containers.