Catalyst 2940 Switch System Message Guide
System Message Overview
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System Message Overview

Table Of Contents

System Message Overview

How to Read System Messages

Error Message Traceback Reports

Output Interpreter

Bug Toolkit

Contacting TAC

System Message Overview

This guide describes the Catalyst 2940-specific system messages. During operation, the system software sends these messages to the console (and, optionally, to a logging server on another system). Not all system messages indicate problems with your system. Some messages are purely informational, whereas others can help diagnose problems with communications lines, internal hardware, or the system software. This guide also includes error messages that appear when the system fails.

This chapter contains these sections:

How to Read System Messages

Error Message Traceback Reports

How to Read System Messages

System messages begin with a percent sign (%) and are structured as follows:


FACILITY is a code consisting of two or more uppercase letters that show the facility to which the message refers. A facility can be a hardware device, a protocol, or a module of the system software. Table 1-1 lists the system facility codes.

Table 1-1 Facility Codes 

Facility Code


Low-level function

"C2950_MONITOR Messages" section


Cluster Membership Protocol

"CMP Messages" section



"DOT1X Messages" section


Dynamic Trunking Protocol

"DTP Messages" section



"EC Messages" section



"ENVIRONMENT Messages" section


Ethernet controller

"ETHCNTR Messages" section


Express Setup

"EXPRESS_SETUP Messages" section


Gigabit Interface Converter (GBIC) module identification and validation

"GBIC Messages" section


GBIC module security

"GBIC_SECURITY Messages" section


GBIC module security

"GBIC_SECURITY_CRYPT Messages" section


GBIC module security

"GBIC_SECURITY_UNIQUE Messages" section


Hardware MAC address table manager

"HWMATM_MOD Messages" section



"PHY Messages" section


Application-specific Integrated Circuit (ASIC) for Catalyst 2950 switches

"PLATFORM_CAT2950 Messages" section


Low-level platform

"PLATFORM_CATALYST2940 Messages" section


Low-level platform messages

"PLATFORM_CATALYST2950 Messages" section


Port manager

"PM Messages" section


Port security

"PORT SECURITY Messages" section


Switch Port Analyzer (SPAN)

"SPAN Messages" section


Spanning tree

"SPANTREE Messages" section


Spanning-tree fast convergence

"SPANTREE_FAST Messages" section


Spanning-tree VLAN switch

"SPANTREE_VLAN_SWITCH Messages" section


Storm control

"STORM_CONTROL Messages" section


VLAN manager

"SW_VLAN Messages" section


UniDirectional Link Detection (UDLD)

"UDLD Messages" section


UplinkFast multicast software

"UFAST_MCAST_SW Messages" section

SEVERITY is a single-digit code from 0 to 7 that reflects the severity of the condition. The lower the number, the more serious the situation. Table 1-2 lists the message severity levels.

MNEMONIC is a code that uniquely identifies the message.

Table 1-2 Message Severity Levels 

Severity Level

0 - emergency

System is unusable.

1 - alert

Immediate action required.

2 - critical

Critical condition.

3 - error

Error condition.

4 - warning

Warning condition.

5 - notification

Normal but significant condition.

6 - informational

Informational message only.

7 - debugging

Message that appears during debugging only.

Message-text is a text string describing the condition. This portion of the message sometimes contains detailed information about the event, including terminal port numbers, network addresses, or addresses that correspond to locations in the system memory address space. Because the information in these variable fields changes from message to message, it is represented here by short strings enclosed in square brackets ([ ]). A decimal number, for example, is represented as [dec]. Table 1-3 lists the variable fields in messages.

Table 1-3 Representation of Variable Fields in Messages 

Type of Information


Decimal integer


Single character


Character string


Ethernet address (for example, 0000.FEED.00C0)


Hexadecimal integer


Internet address

This is a sample system message:

%EC-5-UNBUNDLE:Interface Gi0/1 left the port-channel Po2

The messages in "Message and Recovery Procedures," are described in alphabetical order by facility code with the most severe (lowest number) errors described first.

Error Message Traceback Reports

Some messages describe internal errors and contain traceback information. This information is very important and should be included when you report a problem to your technical support representative.

This message example includes traceback information:

-Process= "Exec", level= 0, pid= 17
-Traceback= 1A82 1AB4 6378 A072 1054 1860 

Some system messages ask you to copy the error messages and take further action. These online tools also provide more information about system error messages.

Output Interpreter

The Output Interpreter provides additional information and suggested fixes based on the output of many CLI commands, such as the show tech-support privileged EXEC command. You can access the Output Interpreter at this URL:

Bug Toolkit

The Bug Toolkit provides information on open and closed caveats, and you can search for all known bugs in a specific Cisco IOS Release. You can access the Bug Toolkit at this URL:

Contacting TAC

If you cannot determine the nature of the error, see the "Obtaining Technical Assistance" section for more information.