CCNA House keeping Logging Synchronous Command.

CCNA House keeping commands
Logging Synchronous Command.

For our students coming into Cisco networking for the first time they are always surprised by a few of the default command settings that are present on the Cisco switches and routers.

These default command settings are a real draw back if left at the default settings so unless the student changes the default settings then the CCNA student is generally going to become increasingly frustrated.

At Commsupport we continually practice the procedure of instructing our CCNA students (and sometimes our CCNP students) that they must change the default settings in order to make their programming via the command line a lot more fluid and without interruption.

The first of our house keeping commands is the “Logging Synchronous” command.
The no logging synchronous command is enabled by default. The purpose of this command is to so that when events occur on your Cisco device these events are reported to the administrators console but unfortunately the messages do by default interrupt the typing and can make life difficult for the administrator to type in command fluidly.

To prevent the console from reporting device events directly to the users console screen you can if you wish completely disable the logging to the console. To disable any logging to the console issue the following command in the global configuration mode:

Router(config)#logging console

If you do decide to disable all logging messages to the console you will lose all visibility of the any events that are occurring on the device, such events may be interfaces enabling or disabling, routing protocols losing or gaining neighbors, or interface duplex mismatches, all of these events are important to you the network administrator.

So that you may retain visibility of events that occur on the device you may wish to log the events to a syslog server on a machine that your device knows of. To turn on syslog on the Cisco device, follow these commads:

Router(config)#logging x.x.x.x

Note: x.x.x.x is the ip address of the P.C with the logging software.

To prevent device events from interrupting your typing but no to prevent the events from being issued onto the console screen you will enter the following command under the line Console prompt, also whilst we are in the line console setting we will also instruct the console that it must never time-out the session even if see that there is no activity i.e. typing commands, this command is the “exec-timeout 0 0”. The two zeros represent minutes and seconds respectively. By setting the values to “0 0” we have instructed the console never to time out

Router(conf)# line console 0
Router(config-line)#no logging synchronous
Router(config-line)#exec-time 0 0

Now when events occur on the Cisco router or switch those very same messages which interrupted your typing will still be displayed onto the console screen but now what ever command you were typing in will simply be dropped down to the next available prompt and no longer chopped in half.

Joe Spoto is a senior lecturer at Commsupport networks CCNA in the United Kingdom. Joe teaches Cisco CCNA, CCNP, CCVP courses when he is not out on the road fixing and building networks, if you want to find out more about what we do at Commsupport please visit us at CCNACommsupport run free one day training sessions and free on-line webinars, CCNP