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Knowing how to properly use logging is a necessary skill forany network administrator. It's vital that you know how to use logging when itcomes time to start troubleshooting.The Cisco IOS offers a great many options for logging. Tohelp bring you up to speed, let's discuss how to configure logging, examine howto view the log and its status, and look at three common errors when it comesto logging.The loggingcommand in Global Configuration Mode and the show logging command in Privileged Mode are two simple but powerfultools to configure and show all Cisco IOS logging options. Let's take a closerlook. Configure logging in the Cisco IOSWhen configuring logging, the most important command to knowis the logging command, used when inGlobal Configuration Mode. Here's an example of this command and its options. You can also send the router's events to a syslog server.This is an external server running on your network.
Most likely, the syslogserver is running on a Linux or Windows server. Because it's external to therouter, there's an added benefit: It preserves events even if the router losespower. A syslog server also provides for centralized logging for all networkdevices.To configure syslog logging, all you need to do is use the logging command and the hostname or IPaddress of the syslog server.
I tried to download and update the router and switches we bought from Cisco, but found the download section closed for non service contr.
So, to configure your Cisco device to use asyslog server, use the following command: Router(config)# logging 10.1.1.1To learn more about using syslog with the Cisco IOS, check outthis TechRepublic download,The Cisco IOS enables logging to the console, monitor, andsyslog by default. But there's a catch: There's no syslog host configured, sothat output goes nowhere.There are eight different logging levels. 0—emergencies. 1—alerts. 2—critical. 3—errors. 4—warnings.
5—notification. 6—informational. 7—debuggingThe default level for console, monitor, and syslog is debugging.The logging on command is thedefault. To disable all logging, use the nologging on command.By default, the router logs anything at the level of debuggingand greater. That means that logging occurs from level 7 (debugging) up tolevel 0 (emergencies). If you want to par down what the system logs, usesomething like the logging consolenotifications command.In addition, the router doesn't enable logging to the systembuffer by default.
That's why you must use the logging buffered command to enable it. View the status of logging and the logging itselfTo view the status of your logging as well as the localbuffered log, use the show loggingcommand.