Openvpn – difference between OpenVPN and PPTP

None is similar in PPP's based on pppd. But there're workarounds as usual: running a check-script from ip-pre-up hook to check for a existing route to the same IP-address is one of them. Beware of race conditions though and use postcontrol as well.

You need to install Openvpn "Openvpn is different like pptp" That is not a problem

http://openvpn.net/index.php/open-source/documentation/howto.html This is good tutorial

PS"Next time pls give us more information abount OS will help us this information"