2.11. Configuring syslog

Overview

Function Introduction

The system message logging software can save messages in a log file or direct the messages to other devices. The system message logging facility has these features:

  • Provides you with logging information for monitoring and troubleshooting.

  • Allows you to select the types of logging information that is captured.

  • Allows you to select the destination of the 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 the severity level. The messages are time-stamped to enhance real-time debugging and management.

You can access the logged system messages using the switch command-line interface (CLI) or by saving them to a properly configured log server. The switch software saves the log messages in an internal buffer that can store up to 1000 messages. You can monitor the system messages remotely by accessing the switch through Telnet or the console port, or by viewing the logs on a log server.

Principle Description

Terminology:

Terminology

Description

Logging

Current logging configuration

Show

Show logging configuration

Levels

Severity level information

Enable

Enable write log to local file

Disable

Disable write log to local file

System Message Log Facility Types

Facility Name

Definition

kern

kernel messages

user

random user-level messages

mail

mail system

daemon

system daemons

auth

security/authorization messages

syslog

messages generated internally by syslogd

lpr

line printer subsystem

news

network news subsystem

uucp

UUCP subsystem

cron

clock daemon

authpriv

security/authorization messages (private)

ftp

ftp daemon

Severity Level Definitions

Severity Level

Definition

emergency

system is unusable

alert

action must be taken immediately

critical

critical conditions

error

error conditions

warning

warning conditions

notice

normal but significant condition

information

Informational

debug

debug-level messages

Configuration

Configuring Logging server

step 1 Enter the configure mode

Switch# configure terminal

step 2 Enable logging server and set the attributes

Switch(config)# logging server enable
Switch(config)# logging server address 1.1.1.1
Switch(config)# logging server address 2001:1000::2
Switch(config)# logging server severity debug
Switch(config)# logging server facility mail

step 3 Exit the configure mode

Switch(config)# end

step 4 Validation

Switch# show logging
Current logging configuration:
============================================================
logging buffer 500
logging timestamp bsd
logging file enable
logging level file warning
logging level module debug
logging server enable
logging server severity debug
logging server facility mail
logging server address 1.1.1.1
logging server address 2001:1000::2
logging alarm-trap enable
logging alarm-trap level middle
logging merge enable
logging merge fifo-size 1024
logging merge timeout 10
logging operate disable

Configuring Logging Buffer Size

By default, the number of messages to log to the logging buffer is 500. If desired, you can set the number between 10 and 1000.

step 1 Enter the configure mode

Switch# configure terminal

step 2 Set the logging Buffer Size

Switch(config)# logging buffer 700

step 3 Exit the configure mode

Switch(config)# end

step 4 Validation

Switch# show logging
Current logging configuration:
============================================================
logging buffer 700
logging timestamp bsd
logging file enable
logging level file warning
logging level module debug
logging server enable
logging server severity debug
logging server facility mail
logging server address 1.1.1.1
logging alarm-trap enable
logging alarm-trap level middle
logging merge enable
logging merge fifo-size 1024
logging merge timeout 10
logging operate disable

The following is the information of logging server:

image

Fig. 2.1 syslog dump on server

Application cases

N/A