Dear @Curtava
Yes, random disconnections for FortiGate VPN users, especially during high network traffic, can be related to bandwidth limits or other network path issues. Here are some steps to troubleshoot and address the issue:
Check Bandwidth Limits: Ensure that there are no bandwidth limits set on the VPN tunnel that could be causing disconnections during high traffic periods.
Network Path Issues: Verify if any network path issues such as ISP traffic shaping, rate-limiting, or packet loss could be affecting the VPN connection.
NAT Device Timeouts: Check if NAT device timeouts are closing translation entries for idle connections, which can cause disconnections.
Keepalive Configuration: Ensure that keepalive messages are configured to maintain the tunnel's active state and prevent it from going idle.
Debugging: Use diagnostic commands to capture and analyze traffic, such as diagnose sniffer packet and diagnose debug application ike -1, to identify any specific issues causing the disconnections.
https://community.fortinet.com/t5/FortiGate/Technical-Tip-Understanding-and-Troubleshooting-IPSec-VP...
Best regards,
Erlin
