Last Modified: Mar 19, 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
Opened: Oct 07, 2025 Severity: 3-Major
On affected F5OS-A appliances running version 1.8.0, specific LAG member ports (3.0 and 7.0) fail to link up after system reboot when configured with 25G speed and FEC disabled. This occurs even when connected to switches that do not support RS_IEEE_FEC/CL108 (such as Cisco Nexus C9508). Other LAG member ports (13.0 and 17.0) in the same configuration come up successfully. The issue persists across multiple EHF releases and requires manual intervention after every reboot.
Interfaces 3.0 and 7.0 do not come up automatically after a reboot.
-- Remote swtichport does not support RS_IEE_FEC/CL108. -- F5 appliance is rebooted. -- FEC is disabled on F5OS-A port. -- Ports 3.0 and 7.0 are part of an LAG.
Follow actions are needed to restore connectivity to 3.0 and 7.0 every time a reboot is performed on the appliance: 1. Change portgroup speed from 25G to 10G for ports 3.0 and 7.0 2. Reboot the appliance 3. Change portgroup speed back from 10G to 25G for ports 3.0 and 7.0 4. Reboot the appliance again 5. Disable FEC via CLI on interfaces 3.0 and 7.0
None