Windows does not connect to L2TP / IPSec server behind NAT¶
By default, Windows OS does not allow connection to L2TP / IPSec server if that one is behind NAT. This case and the method for solving it are described on the sites microsoft.com. For example on the official site и or here.
To allow such a connection, you need to do the following:
Go to the Windows Registry Editor (regedit)
There go to the branch “HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesPolicyAgent”
Add a key with the following parameters:
“Key parameters”¶ key type DWORD (32-bit) Value key name AssumeUDPEncapsulationContextOnSendRule Set the required key value:
“Key value”¶ 0 Windows client connection to L2TP / IPSec server behind NAT is not allowed 1 Windows client connection to L2TP / IPSec server behind NAT is allowed 2 Windows client connection behind NAT, with L2TP / IPSec server behind NAT allowed Restart Windows OS
Connection to L2TP / IPSec servers behind NAT is successful