Configuring Ethernet Interfaces
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:
•
•
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.
To configure flow control on an interface, follow these steps beginning in privileged EXEC mode:
Command
Step 1
configure terminal
Step 2
interface interface-id
Step 3
flowcontrol {receive} {on | off | desired}
Step 4
end
Step 5
show interfaces interface-id
Step 6
copy running-config startup-config
To disable flow control, use the flowcontrol receive off interface configuration command.
This example shows how to turn on flow control on a port:
Switch# configure terminal
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# flowcontrol receive on
Switch(config-if)# end
Configuring Auto-MDIX on an Interface
When automatic medium-dependent interface crossover (auto-MDIX) is enabled on an interface, the
interface automatically detects the required cable connection type (straight through or crossover) and
configures the connection appropriately. When connecting switches without the auto-MDIX feature, you
must use straight-through cables to connect to devices such as servers, workstations, or routers and
crossover cables to connect to other switches or repeaters. With auto-MDIX enabled, you can use either
type of cable to connect to other devices, and the interface automatically corrects for any incorrect
cabling. For more information about cabling requirements, see the hardware installation guide.
Auto-MDIX is enabled by default. Auto-MDIX is supported on all 10/100/1000-Mb/s and on
10/100/1000BASE-TX small form-factor pluggable (SFP)-module interfaces. It is not supported on
1000BASE-SX or -LX SFP module interfaces.
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
1-34
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 either direction. In case of congestion, no indication is
given to the link partner, and no pause frames are sent or received by either device.
Chapter 1
Purpose
Enter global configuration mode
Specify the physical interface to be configured, and enter
interface configuration mode.
Configure the flow control mode for the port.
Return to privileged EXEC mode.
Verify the interface flow control settings.
(Optional) Save your entries in the configuration file.
Configuring Interface Characteristics
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