You want the router to display log messages to your VTY session in real time.
Use the terminal monitor command to enable the displaying of log messages to your VTY:
Router#terminal monitor Router#
To disable logging to your VTY session, use the following command:
Router#terminal no monitor Router#
By default, routers forward all logging messages to their console ports, but not to their VTY lines. When you are troubleshooting a network problem on a remote router, it is often quite useful to instruct the router to send log messages to your VTY so that you can view them in real time. Here is an example showing how to configure the router to display messages with informational severity level and greater (see Table 18-1Table 18-1 for more information about logging severity levels) to VTY lines:
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#logging monitor informational
Router(config)#exit
Router#terminal monitor
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface Fastethernet0/0
Router(config-subif)#shutdown
Router(config-subif)#end
Router#
Mar 26 09:36:43: %LINK-5-CHANGED: Interface Fastethernet0/0, changed state to
administratively down
This example changes the logging monitor level to informational, enables terminal monitoring, and changes the state of an interface to trigger a sample log message. By default, when you enable VTY displaying of log messages, the terminal monitor severity level is set to debugging so that you can see all messages. In this example, we have changed the severity level to informational, which will suppress the printing of debug messages but still display messages with all other severity levels. Keep in mind that setting the severity level for VTY logging is a configuration command, while the command to enable VTY logging, terminal monitor, is a privileged level EXEC command that must be set per session.
Enabling this type of logging makes a Telnet session to a router's VTY port similar to the process of connecting directly to the router's console port. You can use the show logging command to view the current monitor logging configuration:
Router>show logging
Syslog logging: enabled (0 messages dropped, 101 messages rate-limited, 0 flushes, 0
overruns)
Console logging: level debugging, 66712 messages logged
Monitor logging: level informational, 65263 messages logged
Logging to: vty66(0)
Buffer logging: level debugging, 644 messages logged
Logging Exception size (4096 bytes)
Trap logging: level debugging, 3805 message lines logged
Logging to 172.25.1.1, 3805 message lines logged
Log Buffer (8000 bytes):
The bold section of the output shows that the monitor logging facility has been set to a severity level of informational and that one session is currently in use, with the messages being displayed on vty66(0).
Router>show users
Line User Host(s) Idle Location
* 66 vty 0 ijbrown idle 00:00:00 freebsd.oreilly.com
67 vty 1 kdooley idle 00:00:26 solaris.oreilly.com
Router>
You can easily determine which user is currently using the monitor logging facility by issuing the show users command. This output indicates that the user ijbrown is currently using the monitor logging facility.
|
This feature is so useful that enabling it will soon become second nature.
 |
|
|
| Top |
