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INT1
INT1
Explorer
December 4, 2024
Question

VPN IPSEC bytes received 0

  • December 4, 2024
  • 3 replies
  • 6956 views

it happened after a windows update i think im not sure about it i tried unistalling the updates but its still not working what can be the issue?

 

Screenshot 2024-12-04 110628.png

3 replies

sjoshi
Staff
sjoshi
Staff
December 4, 2024

Hi,

 

What is the forticlient version.

Can you try reinstalling the FCT

If you have found a solution, please like and mark it as solved to make it easily accessible for everyone.
    INT1
    INT1Author
    Explorer
    December 4, 2024

    hello, 

    its the latest version 7.4.1, i unistalled it and installed back again didnt work

     

    sjoshi
    Staff
    sjoshi
    Staff
    December 4, 2024

    Is this also affecting your traffic flow via the ssl vpn

    If you have found a solution, please like and mark it as solved to make it easily accessible for everyone.
      link470
      link470
      Visitor III
      February 9, 2025

      @INT1- did you ever get this figured out?  I'm experiencing the exact same problem with a couple machines.  Both Windows 11, both running FortiClient VPN 7.4.1, connecting via IKEv2 IPSec.  They were previously working, now they're not.  No changes have been made on the FortiGate config or on the FortiClient VPN config. 

       

      The connection establishes and shows connected, and on the FortiGate, under Dashboard > IPsec Monitor, I see the connection.  But no traffic passes over the tunnel and Received Bytes stays at 0.

       

      Interestingly enough, using the exact same Windows 11 laptop, I'm able to connect to the same VPN connection on one network (source IP) and transmit data, but on other networks I've tried (including hotspot'd to my phone's WiFi connection), I can connect to VPN, but no data passes.  These other networks were networks where the connection previously passed data no problem over the VPN.

       

      I've tried the following:

      •Uninstalling and reinstalling the Forticlient VPN 7.4.1 software

      •Uninstalling 7.4.1 and installing 7.4.2

      •Disabling IPv6 on the tunnel adapter

      •Disabling IPv6 on all other adapters

      •Installing the latest January Windows 11 updates

       

      So far, nothing has solved the issue.

      funkylicious
      SuperUser
      funkylicious
      SuperUser
      February 9, 2025

      try installing, https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170

      see if you have windows update KB5026372 installed and uninstall it ( this was recommended for SSLVPN but you can try for IPsec )

      also, have a look at https://community.fortinet.com/t5/FortiGate/Technical-Tip-No-bytes-are-received-when-connected-to-IPSEC/ta-p/352403 

      "jack of all trades, master of none"
        link470
        link470
        Visitor III
        February 9, 2025

        > try installing, https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170

         

        I forgot to mention that I'd ensured Visual C++ 2015-2022 was installed as part of installing FortiClient VPN (it was), and I did attempt to update it just in case to the latest version from Microsoft.  This didn't fix the issue.

         

        > see if you have windows update KB5026372 installed and uninstall it

         

        That Windows Update wasn't installed on this machine; that particular update is for Windows 11 v22H2 and I'm running v24H2.

         

        > also, have a look at https://community.fortinet.com/t5/FortiGate/Technical-Tip-No-bytes-are-received-when-connected-to-IP... 

         

        This only applies to IKEv1 connections by the looks of it.  I'm using IKEv2.

         

        Good news though, fixed!  See my reply to MZBZ.

        FortiDor
        FortiDor
        Explorer II
        July 20, 2025

        Hello,

         

        Same problem for me now.

         

        I am working on this topic too :

        https://community.fortinet.com/t5/Support-Forum/IPsec-won-t-split-tunnel/td-p/402089

         

        Any update here ?

        michael2406
        michael2406
        Visitor III
        July 21, 2025

        For me the solution was to check network adapters from Fortinet in "Device-Manager". There were Fortinet Adapters with #2 or #3 at the end. Delete them, afterwars it started to work. 

          FortiDor
          FortiDor
          Explorer II
          July 21, 2025

          Hello @michael2406 

           

          Indeed it works !

           

          Is it a bug in the FCT 7.4.3 with the workaround of deleting the both network adapters ? Something in the Release Notes ?

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