iPhone / VPN Server

Post your questions about SoftEther VPN software here. Please answer questions if you can afford.
Post Reply
Posts: 1
Joined: Thu Mar 26, 2020 12:29 pm

iPhone / VPN Server

Post by ironic » Thu Mar 26, 2020 1:53 pm

Hi all.

This is my first post, thanks for having me!

As a personal project I setup a SoftEther VPN Server on Windows 10 in a spare pc i had (IP ADDRESS:

I also installed the SofEther VPN Client on another Windows 10 pc, the one i use regularly (IP ADDRESS: I installed the certificate and key files and have no problems connecting to the vpn server (

The problem I have is connecting my iphone to the same VPN Server. All 3 devices are connected to the same network, both Windows 10 over ethernet and my iphone wirelessly.

I added the vpn configuration (L2TP) on my iphone but after trying to connect, i get an "Authentication failed" error message.

What am I doing wrong?

Thanks in advance guys!

Posts: 293
Joined: Wed Sep 18, 2013 1:49 pm

Re: iPhone / VPN Server

Post by centeredki69 » Thu Mar 26, 2020 10:42 pm

Is the L2TP/Ipsec setting activated on the SE server? Did you forward UDP ports 500 and 4500 to the SE server address (IP ADDRESS:

If you are trying to connect with the same username and you have chosen certificate authentication on the SE server for the windows SE client it will want a certificate for all types of connections. The L2TP client uses a Username, password and pre-shared so it will not work as the server want a certificate. Create another user for the mobile device and chose password authentication. Or change the exiting user to password authentication.

Post Reply