Technical Tip: Workaround for high CPU usage taking by 'iked.session' daemon in v7.6.1

[yangw]

Description	This article provides a workaround to resolve the 'iked.session takes CPU usage 99%' in v7.6.1 and v7.6.2.
Scope	FortiGate, v7.6.1 and v7.6.2
Solution	Verify the true cause: NTP servers configured over IPsec (set ntpsync enable) are causing iked.session daemon to consume a high CPU of 99.9% in one core after upgrading to v7.6.1 and/or v7.6.2. The command below can be used to trace the CPU usage consuming status to identify the issue if related to the issue: diagnose sys top 5 50 (run it for 20 seconds, press "q" to quit the sys top) diag debug crashlog read Debug output: 4U, 0N, 7S, 89I, 0WA, 0HI, 0SI, 0ST; 16046T, 8407F iked 489 R 99.9 0.2 4 2025-02-07 01:53:19 <00489> firmware FortiGate v7.6.1,build3457b3457,241127 (GA.F) (Release) 2025-02-07 01:53:19 <00489> application iked.session 2025-02-07 01:53:19 <00489> *** signal 11 (Segmentation fault) received *** Action plan: If the debug log matches, it would match the issue. Arrange an available time to upgrade the firmware to v7.6.3.