FortiClient IPSec VPN kills all network connections

[digbo]

Hi all,

I am trying to get my FortiClient IPSec VPN working, but so far without success. I'm using FortiClient 7.0.3.0193 on Windows 10. I have configured the IPSec connection the way the firewall admin told me, but everytime I click on connect it just gets stuck forever at "Status: connecting" without establishing the connection. At the same time, the client kills almost all IPv4 and IPv6 connections from/to my laptop, so I lose all network connectivity until I click on disconnect. The only connection on my laptop that remains online and pingable during the connection phase is the link-local IPv6 address. All other outgoing and incoming pings from and to my machine fail, but as soon as I click disconnect all addresses are pingable and the system goes online again.

At first I thought it was a problem with the credentials so I tested it with identical setting in a Windows 10 VM and there it works perfectly fine. VPN gets established and internet connection remains functional.

What am I missing? I'm thinking it could be some sort of routing issue, perhaps...?

//edit:

I just noticed that the problem only exists when the laptop is connected to my home WiFi. When I connected to my iPhone hotspot instead, it worked immediately. However, the VM I used for testing (mentioned above) is running on the same laptop, so technically it uses the same internet gateway (meaning that it can not be an issue with the router).

[digbo]

OK. I will check with my FortiGate admin and get back to you. Might take a couple of days.

[digbo · Accepted solution]

Update on this. Together with my FortiGate Admin we were able to find and resolve the issue. It was caused by a running service from another VPN client I had installed on my laptop (AVM FRITZ!Box). This client installs 3 services in Windows which are always running even when the client itself is terminated:

AVM FRITZ!Fernzugang Cert Service
AVM FRITZ!Fernzugang Client
AVM FRITZ!Fernzugang IKE Service

Stopping these services resolved the issue. I think it was probably the IKE Service which was blocking access to some IPSec modules in the OS.

[Test85]

That saved my life. I've been struggeling the whole day with an IPsec not connecting.
Stopping these services did the trick.
Thanks!

[ljgazzano]

The problem is caused by the XBOX GAMING service calling the other service: IKE and AuthIP IPSEC keing module.

Try this: 

1- Close Forticlient agent

2- Stop IKE and AuthIP IPSEC keing module.

3- Open Forticlient agent and try connect to IPSEC vpn

If you dont use XBOX GAMING services, try disabling this (or uninstall).
Sometimes, even if the IKE service is disabled, it may start automatically in the background. This is an interesting flaw, so from time to time you will have to stop the service manually. If you uninstall XBOX GAMING, this issue dissapear.

Please tell me if you resolve this