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.

Example

The following example enables flow control on port NETP7.

Console(config)#interface ethernet NETP7

Console(config-if)#flowcontrol

Console(config-if)#no negotiation

Console(config-if)#

Related Commands

negotiation (4-86)

capabilities (flowcontrol, symmetric) (4-87)

4-90Sun Fire B1600 Blade System Chassis Switch Administration Guide • June 2003

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Image 288
Sunfire B1600 manual Following example enables flow control on port NETP7, Consoleconfig#interface ethernet NETP7