Cisco 3560G 48TS Software Configuration Guide - Page 231

Configuring Auto-MDIX on an Interface

Page 231 highlights

Chapter 10 Configuring Interface Characteristics 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: • 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. Note For details on the command settings and the resulting flow control resolution on local and remote ports, refer to the flowcontrol interface configuration command in the command reference for this release. Beginning in privileged EXEC mode, follow these steps to configure flow control on an interface: Step 1 Step 2 Command configure terminal interface interface-id Step 3 Step 4 Step 5 Step 6 flowcontrol {receive} {on | off | desired} end show interfaces interface-id copy running-config startup-config Purpose Enter global configuration mode Enter interface configuration mode and the physical interface to be configured. 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. 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 gigabitethernet0/1 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, refer to the hardware installation guide. Auto-MDIX is disabled by default. When you enable Auto-MDIX, you must also set the speed and duplex on the interface to auto in order for the feature to operate correctly. Auto-MDIX is supported on all 10/100 Mbps interfaces and on 10/100/1000 BASE-T/TX SFP interfaces. It is not supported on 1000 BASE-SX or -LX SFP interfaces. Table 10-2 shows the link states that results from Auto-MDIX settings and correct and incorrect cabling. 78-16156-01 Catalyst 3560 Switch Software Configuration Guide 10-15

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10-15
Catalyst 3560 Switch Software Configuration Guide
78-16156-01
Chapter 10
Configuring Interface Characteristics
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:
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.
Note
For details on the command settings and the resulting flow control resolution on local and remote ports,
refer to the
flowcontrol
interface configuration command in the command reference for this release.
Beginning in privileged EXEC mode, follow these steps to configure flow control on an interface:
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 gigabitethernet0/1
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, refer to the hardware installation guide.
Auto-MDIX is disabled by default. When you enable Auto-MDIX, you must also set the speed and
duplex on the interface to
auto
in order for the feature to operate correctly. Auto-MDIX is supported on
all 10/100 Mbps interfaces and on 10/100/1000 BASE-T/TX SFP interfaces. It is not supported on 1000
BASE-SX or -LX SFP interfaces.
Table 10-2
shows the link states that results from Auto-MDIX settings and correct and incorrect cabling.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode
Step 2
interface
interface-id
Enter interface configuration mode and the physical interface to
be configured.
Step 3
flowcontrol
{
receive
} {
on
|
off
|
desired
}
Configure the flow control mode for the port.
Step 4
end
Return to privileged EXEC mode.
Step 5
show interfaces
interface-id
Verify the interface flow control settings.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.