Bug ID 1086749: Interface speeds are not reported correctly when linked at a slower speed

Last Modified: Oct 19, 2025

Affected Product(s):
F5OS F5OS(all modules)

Fixed In:
F5OS-A 1.4.0, F5OS-A 1.3.0

Opened: Mar 14, 2022

Severity: 3-Major

Symptoms

RSeries 2xxx/4xxx interfaces support linking at certain speeds slower than the portgroup speed, but the interface speed is reported as higher. For example: -- A portgroup in 25G mode accepts a 10G SFP and link at 10G. The interface speed is reported as 25G. -- A portgroup in 25G mode can link at 1G. The interface speed is reported as 25G. -- A portgroup in 10G mode can link at 1G. The interface speed is reported as 10G.

Impact

The interface speed reported in the webUI/CLI is higher than the actual link speed.

Conditions

This occurs when using an SFP that only supports a slower speed, or when connecting a 10G copper port to a 1G capable device.

Workaround

You can determine the actual link speed using ethtool, for example: -- For port 1.0, use ethtool x557_1. -- For port 5.0, use ethtool sfp_5.

Fix Information

Now reports correct interface speeds.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips