Table Of Contents
Message Format
Message Structure
Facility Code
Severity Level
Mnemonic Code
Description Field
System Message Log
Default System Message Log Configuration
Configuring System Message Log Options
Configuring System Message Logging
Configuring the syslog Daemon on UNIX syslog Servers
Configuring syslog Servers
Changing the Log Buffer Size
Changing the Logging Timestamp
Configuring Telnet Login Sessions
Displaying the System Logging Configuration
Displaying System Messages
Message Format
This chapter describes how messages from the switch are formatted and how you can enable the System Message Log feature to send messages to the switch internal buffer and system console for display (and optionally, to a logging server on another system). Not all messages indicate problems; some messages are purely informational, while others help diagnose problems with communications lines, internal hardware, or the system software.
Messages are listed by the facility (hardware device, protocol, or a module or system software) that produces the messages. Within each facility, messages are listed by the severity level, from highest to lowest. Each message is followed by an explanation and a recommended action. Messages appear only when the system remains operational.
The following is a sample system message:
6/17/2001,18:31:15:SYS-5-MOD_INSERT:Module 5 has been inserted
where
6/17/2001,18:31:15 is the date and time of the error (this appears if set for system log messaging).
SYS is the facility type.
5 is the severity level, indicating that it is a normal but significant condition.
MOD_INSERT is the mnemonic code that uniquely identifies the message.
Module 5 has been inserted is the message text.
This chapter contains the following sections:
•
Message Structure
•
System Message Log
Message Structure
The messages include the following information:
•
Facility code
•
Severity level
•
Mnemonic code
•
Description field
For example, the messages are structured as follows:
facility-severity-MNEMONIC:description
Messages from the System Message Log are structured the same, but include this date/time stamp at the beginning of the message:
mm/dd/yyy:hh/mm/ss:facility-severity-MNEMONIC:description
where
is the date and time of the error or event.
Facility Code
The facility code consists of two or more uppercase letters that indicate the facility to which the message refers. A facility can be a hardware device, a protocol, or a module within the system software. Table 1-1 lists the facility codes.
Table 1-1 Facility Codes
Code
|
Facility
|
ACL
|
Access Control Lists
|
CDP
|
Cisco Discovery Protocol
|
COPS
|
Common Open Policy Service
|
DRIP
|
Dual Ring Protocol
|
DTP
|
Dynamic Trunking Protocol
|
DVLAN
|
Dynamic VLAN
|
EARL
|
Enhanced Address Recognition Logic
|
FILESYS
|
Flash File System
|
GVRP
|
GARP VLAN Registration Protocol Messages
|
IP
|
Internet Protocol
|
KERNEL
|
Kernel
|
LD
|
Local Director
|
MCAST
|
Multicast messages
|
MGMT
|
Management messages
|
MLS
|
Multilayer Switching
|
PAGP
|
Port Aggregation Protocol
|
PROTFILT
|
Protocol Filtering
|
PRUNING
|
VLAN Trunking Protocol Pruning
|
PVLAN
|
Private VLAN
|
QOS
|
Quality of Service
|
RADIUS
|
Remote Authentication Dial-In User Service
|
RSVP
|
Resource reSerVation Protocol
|
SECURITY
|
Port Security
|
SNMP
|
Simple Network Management Protocol
|
SNMP RMON
|
Simple Network Management Protocol Remote Monitoring
|
SPANTREE
|
Spanning Tree Protocol
|
SYS
|
System
|
TAC
|
Terminal Access Controller Access Control System Plus
|
UDLD
|
UniDirectional Link Detection Protocol
|
VMPS
|
VLAN Membership Policy Server
|
VTP
|
VLAN Trunking Protocol
|
Severity Level
The severity level is a single digit 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 severity levels.
Table 1-2 Message Severity Levels
Severity Level
|
Description
|
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
|
Mnemonic Code
The MNEMONIC code uniquely identifies the error message. All mnemonics are all uppercase character strings.
Description Field
The description field is a text string that describes the condition. The text string may contain detailed information about the event, including terminal port numbers, network addresses, or addresses that correspond to locations in the system memory address space. Because these variable fields can change from message to message, they are represented by short strings in square brackets ([]). A decimal number, for example, is represented as [dec]. Table 1-3 describes how the variable fields are represented in the messages.
Table 1-3 Representation of Variable Fields
Representation
|
Type of Information
|
[dec]
|
Decimal
|
[chars]
|
Character string
|
[hex]
|
Hexadecimal integer
|
System Message Log
The System Message Log (syslog) software can save system messages in a log file or direct the messages to other devices. The system message logging software has these features:
•
Provides you with logging information for monitoring and troubleshooting
•
Allows you to select the types of logging information captured
•
Allows you to select the destination of captured logging information
By default the switch logs normal but significant system messages to its internal buffer and sends these messages to the system console. You can specify which system messages should be saved based on the type of facility and the severity level. Messages can be time-stamped to enhance real-time debugging and management.
You can access logged system messages using the switch CLI or by saving them to a properly configured syslog server. The switch software saves syslog messages in an internal buffer. You can also save messages on UNIX servers that are configured properly. The syslog software reads the messages from the buffer and sends them to the specified destination.
With syslog, you can access system messages by logging in to the console through Telnet. This allows you to monitor system messages remotely from any workstation that supports the Telnet protocol.
Default System Message Log Configuration
The switches ship with the default configuration shown in Table 1-4.
Table 1-4 Default System Message Log Configuration
Configuration Parameters
|
Default Setting
|
System message logging to the console
|
Enabled
|
System message logging to Telnet sessions
|
Enabled
|
Logging server
|
Disabled
|
Syslog server IP address
|
None configured
|
Server facility
|
LOCAL7
|
Server severity
|
Warnings (4)
|
Logging buffer size
|
500
|
Logging history size
|
1
|
Timestamp option
|
Disabled
|
Facility/severity level for system messages
|
sys/5 dtp/5 pagp/5 mgmt/5 mls/5 cdp/4 udld/4 ld/3 all other facilities/2
|
When you first log on to the switch console, enter the show logging command to display the default configuration.
Configuring System Message Log Options
This section describes how to configure the options for the System Message Log.
Configuring System Message Logging
To change the default system message logging facility and severity levels, perform one of these tasks in privileged mode:
| |
Task
|
Command
|
Step 1
|
Set the default facility and severity level for system messages.
|
set logging level facility severity [default]
|
Step 2
|
Disable system message logging to the console.
|
set logging console disable
|
This example shows how to change the default system message logging facility and severity levels for the Cisco Discovery Protocol (CDP) to severity level 3:
Console> (enable) set logging level cdp 3
System logging facility <cdp> for this session set to severity
3(errors)
Note
To receive syslog messages for a message facility, the server severity level must be set equal to or greater than the default severity level set for the message facility.
This example shows how to disable system message logging to the console:
Console> (enable) set logging console disable
System logging messages will not be sent to the console.
Configuring the syslog Daemon on UNIX syslog Servers
Before you can send system log messages to a UNIX syslog server, you must configure the syslog daemon on the UNIX server.
To configure the syslog daemon, log in as root and perform these steps:
| |
Task
|
Command
|
Step 1
|
Add a line in the file /etc/syslog.conf.1
|
user.debug /var/log/myfile.log2
|
Step 2
|
Create the log file by entering these commands at the UNIX shell prompt.
|
$ touch /var/log/myfile.log $ chmod 666 /var/log/myfile.log
|
Step 3
|
Make sure the syslog daemon reads the new changes by entering this command.
|
$ kill -HUP `cat /etc/syslog.pid
|
Configuring syslog Servers
Before you can send system log messages to a UNIX syslog server, you must configure the syslog daemon on the UNIX server, as described in the section "Configuring the syslog Daemon on UNIX syslog Servers" section. To configure the switch to log messages to a syslog server, perform this task in privileged mode:
| |
Task
|
Command
|
Step 1
|
Add a syslog server to the configuration. You can configure a maximum of three syslog servers at a time
|
set logging server ip_addr
|
Step 2
|
Enable system message logging to configured syslog servers.
|
set logging server enable
|
Step 3
|
Set the facility and severity level for syslog server messages.
|
set logging server facility server_facility_parameter
set logging server severity server_severity_level
|
This example shows how to add a new syslog server with an IP address of 171.69.192.205 to the system logging server table:
Console> (enable) set logging server 171.69.192.205
171.69.192.205 added to the System logging server table.
This example shows how to enable system message logging to a configured syslog server:
Console> (enable) set logging server enable
System logging messages will be sent to the configured syslog servers.
This example shows how to set the syslog server facility to local0:
Console> (enable) set logging server facility local0
System logging server facility set to <local0>
This example shows how to set the syslog server severity level to 4:
Console> (enable) set logging server severity 4
System logging server severity set to <4>
To remove a syslog server from the configuration, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Delete a syslog server from the configuration.
|
clear logging server ip_addr
|
This example shows how to delete the syslog server 171.69.192.207 from the configuration:
Console> (enable) clear logging server 171.69.192.207
System log server 171.69.192.207 removed from system log server table.
To disable logging to the syslog server, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Disable system message logging to configured syslog servers.
|
set logging server disable
|
This example shows how to disable system message logging to a configured syslog server:
Console> (enable) set logging server disable
System logging messages will not be sent to the configured syslog
servers.
Changing the Log Buffer Size
To limit the number of messages buffered, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Change the buffer to limit the number of messages stored.
|
set logging buffer buffer_size
|
This example shows how to limit to 200 the number of messages stored in the buffer:
Console> (enable) set logging buffer 200
System logging buffer size set to <200>
Changing the Logging Timestamp
To enable or disable the system logging messages timestamp, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Enable or disable the timestamp display on system logging messages.
|
set logging timestamp {enable | disable}
|
This example shows how to enable the timestamp display on system logging messages:
Console> (enable) set logging timestamp enable
System logging messages timestamp will be enabled.
Configuring Telnet Login Sessions
By default, system messages are sent to Telnet sessions based on the default facility and severity values.
To configure the logging settings for Telnet sessions, perform one of these tasks in privileged mode:
| |
Task
|
Command
|
Step 1
|
Change the facility and severity values for Telnet login sessions.
|
set logging level facility severity
|
Step 2
|
Disable system message logging to the current Telnet login session.
|
set logging session disable
|
Step 3
|
Disable system message logging to the console.
|
set logging console disable
|
Step 4
|
Reenable system message logging to the current Telnet login session.
|
set logging session enable
|
Step 5
|
Reenable system message logging to the console.
|
set logging console enable
|
This example shows how to change the facility and severity values for Telnet login sessions:
Console> (enable) set logging level cdp 3
System logging facility <cdp> for this session set to severity
3(errors)
This example shows how to disable system message logging to the current Telnet session:
Console> (enable) set logging session disable
System logging messages will not be sent to the current login session.
This example shows how to disable system message logging to the console session:
Console> (enable) set logging console disable
System logging messages will not be sent to the console.
This example shows how to reenable system message logging to the current Telnet session:
Console> (enable) set logging session enable
System logging messages will be sent to the current login session.
This example shows how to reenable system message logging to the console session:
Console> (enable) set logging console enable
System logging messages will be sent to the console.
Displaying the System Logging Configuration
To display the current configuration for system messages, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Display the current system message log configuration.
|
show logging
|
This example shows the results of a show logging command:
timestamp option: enabled
server severity: warnings(4)
Current Logging Session: enabled
Facility Default Severity Current Session Severity
------------- ----------------------- ------------------------
0(emergencies) 1(alerts) 2(critical)
3(errors) 4(warnings) 5(notifications)
6(information) 7(debugging)
To verify the system message log configuration, enter the show logging command. If you are verifying the system message log configuration for the console and the syslog server is disabled, the first five lines of output look as follows:
Console> (enable) show logging
If you are verifying the system message log configuration for a Telnet login session, an additional line showing the current logging session is displayed, as follows:
Console> (enable) show logging
Logging buffer size: 500
Logging console: enabled
Logging server: disabled
Current Logging Session: enabled
Displaying System Messages
To display the first N system messages in the internal buffer of the switch, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Display the first N messages in the buffer.
|
show logging buffer N
|
This example shows how to display the first five messages from the internal buffer:
Console> (enable) show logging buffer 5
%PRUNING-4-NOTRUNK:trunk 100 not found(domain Lab_Network)
%PRUNING-4-NOTRUNK:trunk 100 not found(domain Lab_Network)
%MLS-5-ROUTERDEL:Route Processor 172.20.52.6 deleted - router excluded
from include list
%SYS-5-RTE_DEFGATEFROM:Default Gateway switching from 172.20.52.121
%SYS-5-RTE_DEFGATETO:Default Gateway switching to 172.20.52.125
To display the last N system messages in the internal buffer of the switch, perform this task in privileged mode:
| |
Task
|
Command
|
| |
Display the last N messages in the buffer.
|
show logging buffer [-] [N]
|
This example shows how to display the last five messages from the internal buffer:
Console> (enable) show logging buffer -5
%CDP-4-DUPLEXMISMATCH:Full/half duplex mismatch detected on port 10/1
%DTP-5-TRUNKPORTON:Port 10/1 has become dot1q trunk
%PAGP-5-PORTTOSTP:Port 10/1 joined bridge port 10/1
%SPANTREE-2-RX_1QPVIDERR: Rcved pvid_inc BPDU on 1Q port 10/1 vlan 1.
%SPANTREE-2-TX_BLKPORTPVID: Block 10/1 on xmtting vlan 522 for inc
peer vlan.