How to set up l2tp + ipsec in debian 8.10 for android?

Question

Android

In general, you need to raise a VPN server to connect from Android.
I tried all the manuals on the Internet for setting up l2tp + ipsec.
Also iPhone options.
Android does not want to connect and writes a failure.
Yuzal 2 different devices. Android 6.
Please share the working configs, who has it.
Or give manuals.

Answer 1

The Android VPN client has a bug . In a nutshell, ESP hashing uses the SHA2 algorithm, but in its draft 96-bit implementation. You can configure the server to work with this implementation with the parameter sha2-truncbug=yes, but then clients with normal 128-bit will stop working with it. I was helped by specifying another algorithmesp=aes256-sha2_512