My server runs CentOS 6.2. It has two network cards (eth0 and eth1). In my server I have installed CoovaChilli access controller software, that manages the LAN under it. This management is done through a tunnel that is created by CoovaChilli, and all clients from LAN connect to that tunnel.
Now the problem is that I would like to create a VPN between that server and another remote client (or server). I need some help on doing this, taking in account that I'm new to the topic. I tried to follow VPN HOWTO tutorial, but it is old and some things I think are deprecated. Searching on Internet, I found that there are many ways to create a VPN - I mention just a few: IPSec, OpenVPN, CIPE - and this confused me a little bit.
My VPN will be created between my server that runs CentOS and another remote server that runs Linux also.
What I need: some guidelines on how to achieve that working VPN.
N.B. Any links on this topic are welcome!