Forticlient // VPN doesn't work for 10 minutes then works fine

[Micro-Reseau]

Hello,

Using Forticlient VPN 7.0, we got a weird issue with some users. 
We can connect to our VPN fine but for the first 10min nothing works (access to internal server, network share...) then at 10:00 everything unlocks.
It happens on Windows 10 and Windows 11; tried rolling back to Forticlient 6.4 and 6.2, same issue.

Can't seems to find any fix or workaround other than reinstalling windows from scratch...

Does anyone got a similar issue or have any idea on how to fix this?

[omega]

The description is so vague, this could be nearly everything.

But I would check which DNS-Servers are used (IPV4/IPV6).

[Micro-Reseau]

Hello omega, thanks for the reply,

IPv6 is off, forcing the connexion on IPv4. We had some issue with FortiClient and the IPv6 so now we turn it off by default.
We tried to use the IP and the DNS name to connect, same result.
FortiClient show that the connexion is fine, i can see very small data trafic (never more than 10ko/s), but you can't access anything. And after exactly 10min everything unlocks and work fine.
For more details, we are using FortiClient VPN app, connecting with a ssl VPN on a FortiGate 200F.
Same configuration on every PC, but not everyone has this issue, so i don't think it come from the VPN config, more from the app.

Hard to describe more because there is no clear error. It's just stuck or something.

[Micro-Reseau · Accepted solution]

Ok find the answer, come from Dell. There a service call ConnectExpress that totally mess up FortiClient VPN.  Uninstall Dell Optimizer and Dell Optimizer Service and problem solved. 

[mattw]

Hey @Micro-Reseau ,

I just wanted to say thank you. I had the exact same issue as you. Uninstalling the Dell Optimizer service fixed it.

Thank you! :)

[slippery]

Ran across this today. No Dell Optimizer installed. It was the Killer Performance Driver Suite UWD under Programs & Features. Removed and problem solved.