CLI Reference Guide-R07

Table Of Contents
Chapter 11
| Interface Commands
Interface Configuration
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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
1000BASE-T does not support forced mode. Auto-negotiation should always be
used to establish a connection over any 1000BASE-T port or trunk.
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 802.3-2002 (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
Example
The following example enables flow control on port 5.
Console(config)#interface ethernet 1/5
Console(config-if)#flowcontrol
Console(config-if)#no negotiation
Console(config-if)#
Related Commands
negotiation (363)
capabilities (359)