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New Contributor

FortiClient VPN IPsec can't connect, ISP problem 2


I have problem on one site with connecting VPN FortiClient. 
When I try connect VPN by app it show all the time this communication from screen.

When I change Internet to Mobile HotSpot or just another WiFi I can connect without problems. 
So please help me define what is wrong in my network or ISP.

Should I call ISP and they should unlock something? 
Please help 


Hi, since several data is missing (Windows? Forticlient Version?) try to see if this can help you: -VPN-not-connecting/m-p/242560/highlight/true#M205285

New Contributor

Have you had any luck in finding a solution? I am experiencing the same thing. I am running Forticlient VPN (IPSEC) ver with Windows 10 Pro. I can connect via hot spots, other wifi connections but have isolated it to one site that is using a Sonicwall TZ500. If I bypass their Sonicwall and connect directly to their WAN I can connect.


Hello , 
If you can connect from other networks means that there is no issue with the Forticlient, mostly ISP side. 

I have faced this issue in the past with another VPN client (not Forticlient) and a call to the ISP solved my issue. It is worth giving them a call. 


If you have found a solution, please like and accept it to make it easily accessible for others.



Please install wireshark on PC  and initiate connection by this you will be able to see if there is any reset packet from ISP.
Thaks & Regards
Mayank Sharma

New Contributor III

is that possible to login in VPN IP port number? on a browser with a VPN user name password on the office network?

and check if any blocking is happening on APP proxies 

Honored Contributor

This indeed sounds like that win11 + realtek + Forticlient issue mentioned by FortiMax_it in here.

That happend to me on my win11 pc here too. VPN failed as long as pc was connected to the internet via its ethernet (realtek chipset). Using Wifi for the Internet made it work here too.

I did not apply any workaround as any time I need the VPN I am online via wifi or mobile hotspot ;)


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