I have installed OpenVPN in my Centos machine as OpenVPN server. I generated all authentication certificates, keys and all and it worked fine through the key authentication system. I tested it with my VM.
When I used user authentication method, the client gets connected successfully but doesn't have internet connectivity and cant ping to server tunnel. But client still have ping to the client tunnel. I have double checked the iptables in the server. Tried even disabling iptables. But it does not works.
Problem solved :)
It got fixed when i changed the line in the openvpn server configuration file from
push "redirect-gateway def1"
push "redirect-gateway def"
Anyways..thank u..hope this info will help somebody..