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Flowcontrol, Flowcontrol 4-224 – LevelOne FGL-2870 User Manual

Page 590

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Command Line Interface

4-224

4

Related Commands

negotiation (4-222)
speed-duplex (4-221)
flowcontrol (4-224)

flowcontrol

This command enables flow control. Use the no form to disable flow control.

Syntax

[no] flowcontrol

Default Setting

Disabled

Command Mode

Interface Configuration (Ethernet, Port Channel)

Command Usage

• Flow control can eliminate frame loss by “blocking” traffic from end stations or

segments connected directly to the switch when its buffers fill. When enabled,
back pressure is used for half-duplex operation and IEEE 802.3-2005
(formally IEEE 802.3x) for full-duplex operation.

• To force flow control on or off (with the flowcontrol or no flowcontrol

command), use the no negotiation command to disable auto-negotiation on
the selected interface.

• When using the negotiation command to enable auto-negotiation, the

optimal settings will be determined by the capabilities command. To enable
flow control under auto-negotiation, “flowcontrol” must be included in the
capabilities list for any port

• Avoid using flow control on a port connected to a hub unless it is actually

required to solve a problem. Otherwise back pressure jamming signals may
degrade overall performance for the segment attached to the hub.

Example

The following example enables flow control on port 5.

Related Commands

negotiation (4-222)
capabilities (flowcontrol, symmetric) (4-223)

Console(config)#interface ethernet 1/5
Console(config-if)#flowcontrol
Console(config-if)#no negotiation
Console(config-if)#