Cisco Catalyst 4500 series Administration Manual page 413

Chapter 8 Configuring Interfaces
The following line cards support Auto-MDIX by default, when port auto-negotiation is enabled:
Note
WS-X4424-GB-RJ45, WS-X4448-GB-RJ45,WS-X4548-GB-RJ45 and WS-X4412-2GB-T. You cannot
disable them with the mdix command.
Note The following line cards do not support Auto-MDIX, neither by default nor by CLI:
WS-X4548-GB-RJ45V, WS-X4524-GB-RJ45V, WS-X4506-GB-T,WS-X4148-RJ, WS-X4248-RJ21V,
WS-X4248-RJ45V, WS-X4224-RJ45V and WS-X4232-GB-RJ.
The following line cards support Auto-MDIX through the CLI on their copper media ports:
Note
WS-X4124-RJ45, WS-X4148-RJ45 (hardware revision 3.0 or higher), and WS-X4232-GB-RJ45
(hardware revision 3.0, or higher), WS-X4920-GE-RJ45, WS-4648-RJ45V+E, WS-X4748-UPOE+E
and WS-X4748-RJ45+E (Auto-MDIX support when inline power is disabled on the port).
Table 8-3
Table 8-3
Local Side auto-MDIX
On
On
Off
Off
To configure auto-MDIX on a port, perform this task:
Command
Step 1
Switch# configure terminal
Step 2
Switch(config)# interface
interface-id
Step 3
Switch(config-if)# speed auto
Step 4
Switch(config-if)# mdix auto
Step 5
Switch(config-if)# end
Step 6
Switch# show interfaces
interface-id
Step 7
Switch# copy running-config
startup-config
To disable auto-MDIX, use the no mdix auto interface configuration command.
This example shows how to enable auto-MDIX on a port:
Switch# configure terminal
Switch(config)# interface fastethernet 6/5
Switch(config-if)# speed auto
Switch(config-if)# mdix auto
OL-30933-01
shows the link states that results from auto-MDIX settings and correct and incorrect cabling.
Link Conditions and auto-MDIX Settings
Remote Side auto-MDIX With Correct Cabling
On
Off
On
Off
Purpose
Enters global configuration mode
Enters interface configuration mode for the physical interface to be
configured.
Configures the port to autonegotiate speed with the connected device.
Enables auto-MDIX on the port.
Returns to privileged EXEC mode.
Verifies the configuration of the auto-MDIX feature on the interface.
(Optional) Saves your entries in the configuration file.
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
Configuring Optional Interface Features
With Incorrect Cabling
Link up Link up
Link up Link up
Link up Link up
Link up Link down
8-31