Forticlient VPN 7.4.x "timed out while connecting to ..." IPSec VPN

[pdwoods]

So for whatever reason on new devices that we have set up the past couple of months we cannot seem to connect to our VPN at all on these new devices. However, the older devices seemingly have no issue.  We have tried reinstalling the C++ libraries, reinstalling FortiClient, and updating the NIC driver but have had no luck. 

All of these new devices are running Windows 11 Pro 24H2 and its a mix of 2 Dell Latitude laptops and one Microsoft Surface Pro 9 if that helps with anything.  Also tried looking for some of the older versions on the support page but we don't have the firewall tied to our account so it doesn't let us search through the download page.  I have tried version 5.4.3.0870 of FortiClient that we had saved but that didn't work either although I am not sure if that version is Windows 11 compatible or not. 

Not sure where to go from here any help is appreciated!

[AEK]

When you say FCT VPN 7.4.x, do you mean you also tried 7.4.3?

[pdwoods]

Correct we’ve tried 7.4.3, 7.4.2 (installed about a month ago) and 5.4.3 (installer we had saved)

[ToyinOgunnusiNigeria]

Good Day,

I am experiencing same problem, my device Fortinet 80E, I can't connect new laptop/desktop to my VPN and device EOL is 2026,  kindly assist. 

[pdwoods]

Found a solution that worked for us:

So I took a look at the VPN configuration from another machine that is working and turns out in the extra setting at the bottom there were a few differences

In Phase 1:

DH Group was set 20 when it should have been set to 5

In Phase 2:

Under the second box of Authentication it was using SHA256 instead of SHA1

and

DH Group was set to 20 instead of 5

Hopefully this helps anyone in the future wandering through threads for a solution. 

Also if anyone could inform me why those settings made the difference in solving this I'd love to learn why.

[dingjerry_FTNT]

Hi @pdwoods ,

The FCT VPN settings have to match the VPN settings on FGT.

So how did you configure the VPN settings on FCT?

[pdwoods · Accepted solution]

Here is what the configuration looks like in FCT I am not sure if some default settings got changed in a recent FCT update or if there were changes made to our FGT but usually in the past we could just keep the defaults and not worry about anything besides the gateway and key.

The changes I made are the items circled in red:

 

[dingjerry_FTNT]

Understood.  My suggestion:  Do not rely on the default settings. Always double check the settings to match the VPN configuration on FGT

[ToyinOgunnusiNigeria]

This is very helpful, thank you! 

[test261]

This solution works right away on Windows 10. Thanks for your help and posting the solution. If you're running Windows 11 and it doesn't work, you'll need to install the files from this link first: https://learn.microsoft.com/en-us/answers/questions/4167106/dll-files-missing-after-windows-11-update?forum=windows-all&referrer=answers