The command scheduler will allow you to run commands, or a sequence of commands once or on a recurring basis. This is very similar to the Windows "at" command.
A common request that people have asked me for is to copy a router's running-config to startup-config or to a TFTP server on a certain day of the week every week. This will ensure that no changes are lost if someone forgets to save the config or the router dies.
Here is an example: To get a router to copy the running-config to startup-config every Sunday at 23:00, do the following:
Step 1) Kron policy list
Create a kron policy list - this is your script which lists what commands the router should run at the scheduled time
Router(config)# kron policy-list SaveConfig
Router(config-kron-policy)# cli write
Router(config-kron-policy)# exit
Note:
cli - Specifies EXEC CLI commands within a Command Scheduler policy list.
policy-list - Specifies the policy list associated with a Command Scheduler occurrence.
IMPORTANT: The reason why "write" was used rather than "copy running-config startup-config" is because kron does not support interactive prompts and "copy running-config startup-config" requires interaction. It is important to remember this when creating commands. Also note that kron does not support configuration commands.
Step 2) Create a kron occurrence
Create a kron occurrence, in which you tell the router when and how often you want to run the policy.
Router(config)# kron occurrence SaveConfigSchedule at 23:00 Sun recurring
Router(config-kron-occurrence)
Note:
SaveConfigSchedule - Name of occurrence. Length of occurrence-name is from 1 to 31 characters. If the occurrence-name is new, an occurrence structure will be created. If the occurrence-name is not new, the existing occurrence will be edited.
at - Identifies that the occurrence is to run at a specified calendar date and time.
recurring - Identifies that the occurrence is to run on a recurring basis.
3) Verify
Verify that you've entered everything correctly by using the show command.
r1#sh kron schedule
Kron Occurrence Schedule
SaveConfigSchedule inactive, will run again in 1 days 12:37:47 at 23:00 on Sun
You can see that the schedule is ready to go and will run at the date above.
Note:
inactive - means that kron is not running the command(s) at present. Active means that kron is running the current command(s)
Verify that kron works via debugs:
Router#debug kron exec-cli
Dec 17 22:59:59.999: Call parse_cmd 'write'
Dec 17 23:00:01.587: Kron CLI return 0
'
**CLI 'write':
Building configuration...[OK]'
Dec 17 23:00:59.999: Call parse_cmd 'write'
Dec 17 23:01:01.559: Kron CLI return 0
'
**CLI 'write':
Building configuration...[OK]'
4) View the output of your configuration:
Router# show running-configuration
kron occurrence SaveConfigSchedule at 23:00 Sun recurring
policy-list SaveConfig
kron policy-list SaveConfig
cli write
