I have been searching for couple months and still didn't get the solution to build a VPN application using L2TP/IPSEC PSK using Android native language. I tried ToyVpn but didn't see how you pass username and password to server. I didn't tried openvpn since it didn't support TAP mode. So I just want to ask:
- Is it possible to build L2TP/IPSEC PSK applications for Android 4.x using vpnservice API?
- Is it possible to build L2TP/IPSEC PSK applications for Android 4.x using C# and DotRas (https://dotras.codeplex.com/)?