Cisco Systems 3560 Troubleshooting Power over Ethernet Switch Ports, SFP Module Security and Identification

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Catalyst 3560 Switch Software Configuration Guide

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Chapter 47 Troubleshooting

Troubleshooting Power over Ethernet Switch Ports

Troubleshooting Power over Ethernet Switch Ports

These sections describe how to troubleshoot Power over Ethernet (PoE) ports.

If a powered device (such as a Cisco IP Phone 7910) that is connected to a PoE switch port and is

error-disabled state. To recover from an error-disabled state, enter the shutdown interface configuration

command, and then enter the no shutdown interface command. You can also configure automatic

recovery on the switch to recover from the error-disabled state. The errdisable recovery cause

loopback and the errdisable recovery interval seconds global configuration commands automatically

take the interface out of the error-disabled state after the specified period of time.

Use these commands, described in the command reference for this release, to monitor the PoE port

status:

• show controllers power inline privileged EXEC command

• show power inline privileged EXEC command

• debug ilpower privileged EXEC command

If a Cisco powered device is connected to a port and you configure the port by using the power inline

never interface configuration command, a false link up can occur, placing the port into an error-disabled

state. To take the port out of the error-disabled state, enter the shutdown and the no shutdown interface

configuration commands.

You should not connect a Cisco powered device to a port that has been configured with the power inline

never command.

SFP Module Security and Identification

Cisco small form-factor pluggable (SFP) modules have a serial EEPROM that contains the module serial

number, the vendor name and ID, a unique security code, and cyclic redundancy check (CRC). When an

SFP module is inserted in the switch, the switch software reads the EEPROM to verify the serial number,

vendor name and vendor ID, and recompute the security code and CRC. If the serial number, the vendor

name or vendor ID, the security code, or CRC is invalid, the software generates a security error message

and places the interface in an error-disabled state.

Note The security error message references the GBIC_SECURITY facility. The switch supports SFP modules

and does not support GBIC modules. Although the error message text refers to GBIC interfaces and

modules, the security messages actually refer to the SFP modules and module interfaces. For more

information about error messages, see the system message guide for this release.

If you are using a non-Cisco SFP module, remove the SFP module from the switch, and replace it with

a Cisco module. After inserting a Cisco SFP module, use the errdisable recovery cause gbic-invalid

global configuration command to verify the port status, and enter a time interval for recovering from the