L2TP connection problem

Hello evrybody,

I have a problem with my VPN connection on my Ipad.
When my Ipad device is connected tot the server, It can't find any server on the internet.
I tested the VPN with my pc and andriod device. It worked fine with them. Only the Ipad isn't working correctly.

The error that is displayed on safari:
Safari can't open the page because the server is unfindable.

The VPN server is Windows Server 2012 R2
Remote acces interface displays the following Details

Activity Status = Active
Authentication method = MSChapv2

Total bytes = 13537

Is the Authentication the problem? I tried to change it, I won't let me

Thanks