vpn connection random

[anneso]

My colleague randomly connects to the vpn.
Here is the error message
"unable to establish the vpn connection the server may be unreachable on your identity cetificate is not trust"
The firewall 's log says the disconnection came from the customer
I performed the following actions
I verified network driver 
I reinstalled the client
I made a dns flash
I updated the version of forticlient
I deasabled tsl option 
Have you got any solution ?

[sss]

Hello,

Since Certificates are used for authentication + dial-up, based on my experience this might very well be a case of MTU issue.  Worth checking MTU or first try with simple user+password if that works.

Best Regards,

SSS

[anneso]

Hello

The cpu values ​​are correct

[darisandy]

on SSL-VPN Setting, did you enable "Require Client Certificate"?

if it is, you may want to try to disable it and test the connection.

[sss]

Hello anneso,

First question: Is it SSL or IPSec dial-up VPN?

Second, I was mentioning MTU; not about CPU.

Third, have you tested with simple user/password authentication? May be worth a try.

Best Regards,

SSS

[anneso]

Hi sss

I will answer your questions

it's an dial up vpn

I made a typo. I was talking about mtu

I must add that this problem happened when my colleague updated windows 21H2

(excuse me for my english i am franch.)