VPN Mesh / VPN P2P Software

Hello, We need vpn mesh or vpn p2p software that can do something like this 1. first client connect to server and get ip address from server like [login to view URL] netmask [login to view URL] 2. second client connect to server and get ip address from server like [login to view URL] netmask [login to view URL] 3. third client connect to server and get ip address from server .... 4. when first client want to communicate with second client it must be p2p connection that mean all traffic will not pass through main server My requirement 1. Small application for win32 install . any solution or language is accept . (Don't need any interface) only install and get ip address 2. auto start up when windows start 3. compatible to running in Centos (version 5 and 6) *additional 4. You can use any free open source to implement but It must be easy to use for our client like only click for install and finish !! Any suggestion is welcome Best Regards, Filesseo