flow-control

Enables or disables flow control and flow control negotiation, and advertises flow control.
Syntax
flow-control [ both | generate-only | honor-only ]
no flow-control [ both | generate-only | honor-only ]
Command Default

Flow control is enabled.

Parameters
both

Flow control in PAUSE generation and honoring mode.

generate-only

Flow control in PAUSE generation only mode.

honor-only
Flow control in PAUSE honoring (Default) mode.
Modes

Global configuration mode

Interface configuration mode

Usage Guidelines

On ICX 7750 devices the default packet-forwarding method is cut-through, in which port flow control (IEEE 802.3x) is not supported but priority-based flow control (PFC) is supported. You can configure the store-and- forward command in global configuration mode to enable the store-and-forward method for packet-forwarding.

The recommended flow control settings when the ICX 7750 switch is set for store-and-forward are listed in the following table.

Symmetrical flow control Port-based flow control Configuration commands Cut-through (Jumbo enabled) Store-and-Forward (Jumbo Enabled)
disabled honor-only # flow-control honor-only Not Recommended OK
no flow-control-both #no flow-control both OK OK
enabled no flow-control-both

#symmetrical-flow-control enable

# no flow-control both

OK OK
honor-only

# symmetrical-flow-control enable

#flow-control honor-only

Not Recommended OK
generate-only

# symmetrical-flow-control enable

# flow-control generate-only

OK OK
both

# symmetrical-flow-control enable

#flow-control both

Not Recommended OK

You can configure the store-and- forward command in global configuration mode to enable the store-and-forward method for packet-forwarding.

By default, when flow control is enabled globally and auto-negotiation is on, flow control is enabled and advertised on 10/100/1000M ports. If auto-negotiation is off or if the port speed was configured manually, flow control is neither negotiated with nor advertised to the peer.

Note: Enabling only port auto-negotiation does not enable flow control negotiation. You must use the flow-control neg-on command to enable flow-control negotiation.

The no form of the command disables flow control.

Examples

The following example disables flow control globally. 

device(config)# no flow-control

The following example enables flow control on ethernet ports 1/1/11 to 1/1/15. 

device(config)# interface ethernet 1/1/11 to 1/1/15
device(config-mif-1/1/11-1/1/15)# flow-control

The following example disables flow control on ethernet port 1/1/9. 

device(config)# interface ethernet 1/1/9
device(config-if-e1000-1/1/9)# no flow-control
History
Release version Command history
08.0.20 This command was modified. Enabling only auto-negotiation does not enable flow-control negotiation.
Parent topic: Commands D through H