Table 154 Error Messages Logging and Syslog Levels

Level Keyword

Level

Description

Syslog Definition

Emergencies

0

System unusable

LOG_EMERG

Alerts

1

Immediate action needed

LOG_ALERT

Critical

2

Critical conditions

LOG_CRIT

Errors

3

Error conditions

LOG_ERR

Warnings

4

Warning conditions

LOG_WARNING

Notifications

5

Normal but significant condition

LOG_NOTICE

Informational

6

Informational messages only

LOG_INFO

Debugging

7

Debugging messages

LOG_DEBUG

Logging is enabled by default on Cisco routers. Log messages are sent to any of five locations, which are not mutually exclusive:

• The console port, enabled via the logging console level global configuration command.

• A circular buffer in RAM, which is enabled and sized using the logging buffered [size] global configuration command.

• The terminal lines, enabled via the logging monitor level global configuration command; virtual terminals (such as Telnet connections) can attach to this output via the terminal monitor exec command.

• A syslog server, via the logging trap level global configuration command.

• A SNMPtrap server, enabled via the snmp-server enable trap syslog, and with the level set by the logging history global configuration commands.

In most cases, the best solution for a large network is to configure all critical routers to log all messages to a syslog server within the NMS, in which they can be properly monitored and archived. Again, the definition of "critical" is not always clear, but certainly all core and any distribution routers aggregating large numbers of customers are prime candidates.

By default, only messages at the informational level or above are sent to the syslog server. However, this may be adjusted using the logging trap global configuration command. You may wish to set the level to debug to aid the troubleshooting process. Messages are sent to the local facility, although this can be changed using the logging facility facility-type global configuration command.

Was this article helpful?

0 0

Post a comment