Frequent Automatic Disconnections with IPsec VPN Servers in FortiClient 7.4

[lxh395252851]

I'm using IPsec VPN with FortiClient 7.4. I've configured two IPsec VPN servers (primary and backup) and deployed the settings to clients via FortiClient EMS. However, during usage, the connection to the primary server consistently drops every 30 to 60 minutes, while the backup server disconnects even more frequently and irregularly.

All components are running version 7.4, and there’s no packet loss between the public networks involved. This issue affects all users in our environment.

Has anyone encountered this behavior? Any suggestions on how to troubleshoot or resolve it would be greatly appreciated.

[AEK]

Which FortiClient version exactly (I mean the x in 7.4.x)?

Can you try connecting your client using other internet link or other ISP?

[Carson_Daniels]

Hi — frequent disconnections with FortiClient 7.4 IPsec VPN are often caused by IKE or dead peer detection (DPD) timers being too short, or NAT/keepalive issues. Try the following:

Increase the IKE SA and DPD timers on both VPN servers.

Enable VPN keepalive/ping to maintain the tunnel.

Check for overlapping subnets or duplicate IP assignments that might trigger rekeying.

Review client logs for specific error codes to pinpoint the drop reason.

These steps usually stabilize connections and reduce frequent automatic disconnections.