4 Command Line Interface

Example

The following example configures Ethernet port 5 capabilities to 100half, 100full and flow control.

Console(config)#interface ethernet 1/5

Console(config-if)#capabilities 100half

Console(config-if)#capabilities 100full

Console(config-if)#capabilities flowcontrol

Console(config-if)#

Related Commands

negotiation (4-118)speed-duplex(4-117) flowcontrol (4-120)

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 802.3x 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.

4-120

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SMC Networks SMC8150L2 Flowcontrol, Negotiation 4-118speed-duplex4-117 flowcontrol, Syntax No flowcontrol Default Setting