Bug ID 708415: Interface Flow Control Status does not update when using copper SFPs and Link Partner Flow Control is disabled

Last Modified: Nov 07, 2022

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.0.0,,,,,, 14.0.1,

Fixed In:

Opened: Mar 01, 2018
Severity: 4-Minor


When setting the flow control value of an interface with a copper SFP to any value other than 'none' and the link partner has flow control disabled on their end, the interface stats will not reflect the configured flow control setting. This is because the interface stats reflect the negotiated link state rather than the advertised capabilities.


There is no functional impact, as flow control cannot be performed until both link partners agree to support it.


BIG-IP device is using copper SFPs. -- Flow control is enabled on an interface. -- That interface is connected to another device where flow control has not been enabled. For example, an administrator might perform the following on a BIG-IP system with a copper SFP on interface 1.1: # modify net interface 1.1 flow-control tx-rx # show net interface 1.1 all-properties Under the 'Flow Ctrl' column of the interface properties, the value will indicate 'none' even though the interface was configured to enable transmit and receive flow control. This is because the column does not indicate the advertised capabilities but rather the negotiated property of the link.


Flow control must be enabled on the remote device and the link must be re-negotiated, in order for the flow control configuration to take effect and be reflected in the interface properties of the link.

Fix Information

Interface Flow Control Status is now updated when using copper SFPs and Link Partner Flow Control is disabled. Note: The 'Flow Ctrl Req' label under 'tmsh show net interface all-properties' differs in previous versions: 'Flow Ctrl'. The value listed is the same, however, and represents the admin-requested value, and not the operational value.

Behavior Change