Last Modified: Aug 25, 2026
Affected Product(s):
F5OS F5OS-A
Known Affected Versions:
F5OS-A 1.8.0, F5OS-A 1.8.1, F5OS-A 1.8.2, F5OS-A 1.8.3, F5OS-A 1.8.4, F5OS-A 1.8.4-HR1
Opened: Oct 15, 2025 Severity: 3-Major
Some packets destined to the internal Kubernetes API server may leave the system's management port towards the configured management gateway for up to 10 seconds during platform services shutdown or reboot. These packets will be destined to an IP address in the internal network range on TCP port 6443, by default 100.64.0.0/12 (RFC6598).
There is no known impact to system operation. Packets will no longer leave the management port once platform services start up again, which happens automatically on system startup. The small number of "leaked" packets may occasionally be observed in monitoring or logs from external systems such as firewalls.
Platform services are shutting down, typically during a system reboot.
The following workaround will stop the packets into management interface. As a root user need to add following dummy route. e.g. ip route add unreachable 100.64.0.0/12 metric 1000 table main Based on network prefix, the IP Address 100.64.0.0/12 need to be adjusted to relevant prefix.
None