Port Status and Configuration

Viewing Port Status and Configuring Port Parameters

Table 10-4. Cable Types for Auto and Manual MDI/MDI-X Settings

 

MDI/MDI-X Device Type

Setting

PC or Other MDI Device Type

Switch, Hub, or Other MDI-X Device

 

 

 

Manual MDI

Crossover Cable

Straight-Through Cable

 

 

 

Manual MDI-X

Straight-Through Cable

Crossover Cable

 

 

 

Auto-MDI-X

Either Crossover

or Straight-Through Cable

(The Default)

 

 

 

 

 

The Auto-MDIX features apply only to copper port switches using twisted-pair copper Ethernet cables.

Syntax: interface < port-list> mdix-mode < automdix mdi mdix >

automdix is the automatic, default setting. This configures the port for automatic detection of the cable (either straight-through or crossover).

mdi is the manual mode setting that configures the port for connecting to either a PC or other MDI device with a crossover cable, or to a switch, hub, or other MDI-X device with a straight- through cable.

mdix is the manual mode setting that configures the port for connecting to either a switch, hub, or other MDI-X device with a crossover cable, or to a PC or other MDI device with a straight- through cable.

Syntax: show interfaces config

Lists the current per-port Auto/MDI/MDI-X configuration.

Syntax: show interfaces brief

Where a port is linked to another device, this command lists the MDI mode the port is currently using. In the case of ports configured for Auto (automdix), the MDI mode appears as either MDI or MDIX, depending upon which option the port has negotiated with the device on the other end of the link. In the case of ports configured for MDI or MDIX, the mode listed in this display matches the configured setting. If the link to another device was up, but has gone down, this command shows the last operating MDI mode the port was using. If a port on a given switch has not detected a link to another device since the last reboot, this command lists the MDI mode to which the port is currently configured.

For example, show interfaces config displays the following data when port 1 is configured for auto-mdix, port 2 is configured for mdi, and port 3 is configured for mdix.

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