qos flowcontrol

Configures link-level flow control (IEEE 802.3x Flow Control) in the transmission and reception direction on an interface or enables priority flow control on a CoS of an SLX 9150 or SLX 9250 interface.

Syntax

qos flowcontrol [ pfc CoS-number ]tx { on | off } rx { on | off }

no qos flowcontrol

Command Default

By default, link-level flow control (LLFC) reception is enabled.

Parameters

pfc CoS-number: (Optional) Enables priority flow control (PFC) on the specified CoS of an SLX 9150 or SLX 9250 interface. For the CoS-number variable, enter an integer from 0 to 7.
tx { on | off }: Activates or deactivates the transmission portion of flow control.
rx { on | off }: Activates or deactivates the reception portion of flow control.

Modes

Interface configuration mode

Usage Guidelines

LLFC alleviates system congestion by pausing data transmission. LLFC allows a congested receiver to communicate a PAUSE frame to a transmitter to stop data transmission until the congestion is cleared.

The device supports the transmission (Tx) and reception (Rx) of PAUSE frames for each physical interface or port channel.

LLFC can be configured only at the interface level.

Before configuring LLFC on an interface, stop the traffic on the interface.

Use the no form of this command to reset the default behavior.

Examples

The following example configures flow control on an interface.

device# configure terminal
device(config)# interface ethernet 1/4
device(conf-eth-1/4)# qos flowcontrol tx on rx on

The following example enables PFC on CoS 2 of an SLX 9150 interface.

device# configure terminal
device(config)# interface ethernet 0/1
device(conf-eth-0/1)# qos flowcontrol pfc 2 tx on rx on