VPN fails for iOS and Android devices

L2TP and PPTP VPN set up on OS X Server 3.0 fails when connection is made from iOS or Android device. When connecting from a MacBook Air running Maverick it all works fine. Exact same client settings are done on iOS and OS X.

When connecting from OS X, Server VPN log shows all the details. But when trying to connect from iOS and even from my Android, there is not a single entry in the Server logs that anything even reaches the server.

I checked using TCPMon and using PPTP and was clearly showing that packages were forwarded to the server. But still nothing showed in the log.