FortiClient
FortiClient proactively defends against advanced attacks. Its tight integration with the Security Fabric enables policy-based automation to contain threats and control outbreaks. FortiClient is compatible with Fabric-Ready partners to further strengthen enterprises’ security posture.
btan
Staff & Editor
Staff & Editor
Article Id 402369
Description This article describes how to troubleshoot an issue whereby, while attempting a VPN connection with Smart Card PKI authentication, the FortiClient VPN progress failed at 40% and would not ask for the PIN code to proceed with the connection.
Scope FortiClient v7.2, and v7.4.
Solution

VPN setup:

  1. Follow this document: SSL VPN with certificate authentication and configure SSL VPN or IPsec VPN with certificate authentication.
  2. Follow this document SSL VPN and configure the VPN to 'Require Certificate'.

 

Note: In some cases, additional settings on FortiGate may be required, depending on the article Technical Tip: Upgrade to the latest MS Windows 10 version breaks the SSLVPN login using PKI with so...:

 

config vpn ssl settings
    set client-sigalgs no-rsa-pss
end

 

In a successful VPN scenario:

  1. Select the correct certificate for VPN connection, and FortiClient will prompt the user to enter the PIN code for the certificate.

 

july-kb3-suc1.png

 

  1. After inputting the correct PIN code, FortiClient will proceed with the VPN connection and connect successfully.

 

In a failure VPN scenario:

  1. Select the correct certificate for VPN connection, FortiClient pauses the progress at 40%.

 

july-kb3-fail1.png

 

  1. FortiClient did not prompt the user to enter the PIN code and dropped the VPN attempt abruptly.

 

july-kb3-fail2.png

 

When facing the above issue, follow the guidelines below to troubleshoot (applicable to both FortiClient VPN-only version and FortiClient full-version):

  1. Check the machine's Windows version, which can be checked by running a CMD command: winver.
    Windows 10 version 17134 (21H1) or older: Use FortiClient v7.2.11+.
    Windows 10 version 19044 (21H2) or newer: Use FortiClient v7.4.3+.
    Windows 11 version: Use FortiClient v7.4.3+.

  2. If the above has been verified but the issue still persists, open Registry Editor, go to HKEY_LOCAL_MACHINE\SOFTWARE\Fortinet\FortiClient\Sslvpn\Tunnels\tunnelname.
  • Check if there is a dual_stack registry; by right, there should be none; if it exists, it should be set to 0.

 

july-kb3-4.png

 

  • In case the dual_stack registry exists and has been set to 1, manually edit it to 0.
  • If the FortiClient is managed by EMS, manually add/edit the parameter <dual_stack>0</dual_stack> in the endpoint profile.

 

july-kb3-3.png

 

  1. If the issue persists even after dual_stack is set to 0, add an async_mode registry (DWORD 32 bit) and set it to 1.

 

july-kb3-2.png

 

If the FortiClient is managed by EMS, manually add the parameter <async_mode>1</asycn_mode> in the endpoint profile.

 

july-kb3-1.png

 

After verifying all 3 steps above, the issue should be resolved.

 

Further reading about async_modeAsynchronous Operation.

 

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