USG110 FW 4.62 and L2TP VPN with iOS 14.4.x not working

padavjer Posts: 2
First Comment
edited April 2021 in Security
Hello all

I have been trying for a while now to connect iOS devices with 14.4.x installed over L2TP IPSec PSK to a USG110 with FW 4.62

The issue only appears on iOS devices. There are no issues connecting Windows 10 devices or Android devices (Android 11).

I have read on different apple support pages that the encryption should be changed to SHA128 or SHA256. I did this for phase 1 and 2 but with no success.

Has anybody successfully connected an iOS device with the latest version to a USG firewall with the latest firmware over L2TP?


All Replies

  • Zyxel_Can
    Zyxel_Can Posts: 342
    5 Answers First Comment Friend Collector
     Zyxel Employee

    @Hi padavjer,


    In our lab, we created environment for USG110 with latest version.


    Can you try to create L2TP VPN setting with Quick Setup and try to connect again?


    For that, in Expert mode click “Quick Setup” on the left hand side of the GUI.

    Choose Remote Access VPN Setup > L2TP over IPSec Client(iOS, Windows, Android)

    Best regards.
  • padavjer
    padavjer Posts: 2
    First Comment

    Thank you for your answer. That was actually the first thing I did. It also created me a *.mobileconfig file that I was able to install on an iPad and an iPhone.

    The base encryption settings from the wizard was 3DES and SHA1 (both for phase 1 and phase 2). On some apple blogs it is mentioned that the new iOS is not supporting this type of encryption/authentication anymore. That is why I changed it to AES256/SHA256. Every other configuration was not touched. After changing this the Android devices still worked...the iPhones not.

  • Motivio
    Motivio Posts: 21
    Friend Collector First Anniversary
     Freshman Member
    For me it works with AES128/SHA1 but not with SHA256. Is this something iOS is not supporting?
  • Zyxel_Can
    Zyxel_Can Posts: 342
    5 Answers First Comment Friend Collector
     Zyxel Employee
    Hi @Motivio, @padavjer,

    Can you try applying following configuration?
    Configuration > VPN > IPSec VPN > VPN Gateway

    Configuration > VPN > IPSec VPN > VPN Connection

    Configuration > VPN > L2TP VPN

    With this setup iOS 14.4.2 can connect via VPN.

    What is your device's iOS version?

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