09.12.2012 Views

Understanding the network.pdf - Back to Home

Understanding the network.pdf - Back to Home

Understanding the network.pdf - Back to Home

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

00:00:08: %LINK-3-UPDOWN: Interface E<strong>the</strong>rnet0/0, changed<br />

state <strong>to</strong> up<br />

00:00:08: %LINK-3-UPDOWN: Interface E<strong>the</strong>rnet0/1, changed<br />

state <strong>to</strong> up<br />

Cisco uses <strong>the</strong> syslog level classification <strong>to</strong> define <strong>the</strong> severity of<br />

logging messages:<br />

Message Severity Level Meaning Explanation<br />

0 Emergencies System is unusable<br />

1 Alerts Immediate action needed<br />

2 Critical Critical conditions<br />

3 Errors Error conditions<br />

4 Warnings Warning conditions<br />

5 Notifications Normal but significant conditions<br />

6 Informational Informational messages<br />

7 Debugging Debugging messages<br />

Each level sends messages recursively. If <strong>the</strong> warning's level is set, all<br />

message levels below it are sent as well, so <strong>the</strong> message level defines<br />

what classes of messages will be sent. The default logging<br />

configuration has all router event messages logged. This is achieved<br />

with <strong>the</strong> logging level set <strong>to</strong> debugging:<br />

Router#sh logging<br />

Syslog logging: enabled (0 messages dropped, 0 flushes, 0<br />

overruns)<br />

Console logging: level debugging, 15 messages logged<br />

Moni<strong>to</strong>r logging: level debugging, 0 messages logged<br />

Trap logging: level informational, 19 message lines logged<br />

Buffer logging: disabled<br />

It is possible <strong>to</strong> define which logging level will be sent <strong>to</strong> which logging<br />

method (console, moni<strong>to</strong>r, trap, or buffer). The global configuration<br />

command is used <strong>to</strong> set <strong>the</strong> logging<br />

method's message level. This can be quite helpful, especially if you

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!