Catalyst 3550 Multilayer Switch System Message Guide, 12.1(4)EA1
System Message Overview
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System Message Overview

Table Of Contents

System Message Overview

How to Read System Error Messages

Error Message Traceback Reports

System Message Overview

This guide describes the IOS system error messages for the switch. The system software sends these error messages to the console (and, optionally, to a logging server on another system) during operation. Not all system error messages indicate problems with your system. Some messages are purely informational, while 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 Error Messages

Error Message Traceback Reports

How to Read System Error Messages

System error 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 



Cluster Membership Protocol

"CMP Messages" section


CPU network interface

"CPU Network Interface Messages" section


Dynamic Trunking Protocol

"Dynamic Trunking Protocol Messages" section



"EtherChannel Messages" section


Ethernet controller

"Ethernet Controller Messages" section


Feature manager

"Feature Manager Messages" section


GigaStack GBIC

"GigaStack GBIC Module Messages" section


Layer 2 forwarding manager

"Layer 2 Forwarding Manager Messages" section


Catalyst 3550 switch

"Catalyst 3550 Platform Messages" section


Port manager

"Port Manager Messages" section


Quality of service (QoS) classification and security ACL manager

"QoS Classification and Security ACL Manager Messages" section


QoS manager

"QoS Manager Messages" section


Spanning tree

"Spanning-Tree Messages" section


Spanning-tree fast convergence

"Spanning-Tree Fast Convergence Messages" section


UniDirectional Link Detection (UDLD)

"UDLD Messages" section


VLAN manager

"VLAN Manager 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 error 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




Single character


Character string


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


Hexadecimal integer


Internet address

The following is a sample system error message:

%LINK-2-BADVCALL: Interface [chars], undefined entry point

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 sample message includes traceback information:

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