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Catalyst 2960 Switch SoftwareConfiguration Guide
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Chapter10 Configuring Interface Characteristics
Configuring Ethernet Interfaces
This example shows how to set the interface speed to 100 Mbps on a 10/100/1000 Mbps port:
Switch# configure terminal
Switch(config)# interface gigabitethernet0/2
Switch(config-if)# speed 100
Configuring IEEE 802.3x Flow Control
Flow control enables connected Ethernet ports to control traffic rates during congestion by allowing
congested nodes to pause link operation at the other end. If one port experiences congestion and ca nnot
receive any more traffic, it notifies the other port by sending a pause frame to stop sending until the
condition clears. Upon receipt of a pause frame, the sending device stops sending any data packets,
which prevents any loss of data packets during the congestion period.
Note Catalyst 2960 ports can receive, but not send, pause frames.
You use the flowcontrol interface configuration command to set the interface’s ability to receive pause
frames to on, off, or desired. The default state is off.
When set to desired, an interface can operate with an attached device that is required to send
flow-control packets or with an attached device that is not required to but can send flow-control packets.
These rules apply to flow control settings on the device:
•receive on (or desired): The port cannot send pause frames but can operate with an attached device
that is required to or can send pause frames; the port can receive pause frames.
•receive off: Flow control does not operate in ei ther direction. In case of congestion, no indication is
given to the link partner, and no pause frames are sent or received by either device.
Note For details on the command settings and the resulting flow control resolution on local and remote ports,
see the flowcontrol interface configuration command in the command reference for this release.
Beginning in privi leged EXEC mode , follow these ste ps to configure flow control on an interface:
To disable flow control, use the flowcontrol receive off interface configuration command.
Command Purpose
Step1 configure terminal Enter global configuration mode
Step2 interface interface-id Specify the physical interface to be configured, and enter
interface configuration mode.
Step3 flowcontrol {receive} {on | off | desired} Configure the flow control mode for the port.
Step4 end Return to privileged EXEC mode.
Step5 show interfaces interface-id Verify the interface flow control settings.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.