FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
This article describes a session timeout issue in which the Session expiration timer continues to count down even with continuous traffic, resulting in a session timeout.
Scope
FortiGate v7.0, v7.2, v7.4.
Solution
Session expiration doesn't get updated for offloaded traffic to/from a specific host range (x.x.x.[224-239]).
This bug, 971404, only happened to the NP7 models.
To resolve the session timeout issue, follow these steps:
Identify the FortiGate version: Check the FortiGate version to see if it is affected by the bug. The bug affects versions before v7.0.14, v7.2.8, and v7.4.4.
Disable auto-asic-offload: If the FortiGate OS version is affected, disable auto-asic-offload on the firewall policy to prevent session timeout issues. By default, the auto-asic-offload is enabled in the firewall policy. This can be done by using the following command:
config firewall policy
edit 1
set auto-asic-offload disable next end
Upgrade to a fixed version: To permanently resolve the issue, upgrade the FortiGate to a version that includes the bug fix, such as v7.0.14, v7.2.8, or v7.4.4.
