Poor mans kron
January
03
, 2018
Use the Cisco IOS command scheduler
For example, let's say you want to automatically back up your router's running configuration (in RAM) to the startup configuration (in NVRAM) every Monday night at 10 P.M. You might want to make sure that the system is preserving router changes, even if the router losses power and even if someone forgets to save his or her changes.
The new IOS command scheduler makes this a relatively easy task. Here's how you can use kron to accomplish this.
First, create a kron policy list. Essentially, this policy list serves as your "script," which lists what you want the router to run at a scheduled time. Here's an example:
TERMINAL
- Router(config)# kron policy-list backup
- Router(config-kron-policy)# cli write
- Router(config-kron-policy)# exit
Next, create a kron occurrence, in which you tell the router when and how often you want to run this policy list (i.e., group of commands). Here's an example:
TERMINAL
- Router(config)# kron occurrence backup at 22:00 Mon recurring
- Router(config-kron-occurrence)# policy-list backup
This code sets up your backup job to run every Monday night at 10 P.M. (22:00 in military time).
Finally, verify that you've entered everything correctly by using the show command.
TERMINAL
- Router# show kron schedule
- Kron Occurrence Schedule
- backup inactive, will run again in 2 days 22:03:46 at 22:00 on Mon
TERMINAL
- Router# show running-configuration
- (truncated)
- kron occurrence backup at 22:00 Mon recurring policy-list backup
- !
- kron policy-list backup cli write
- (truncated)
You might be wondering why I used the write command instead of the copy running-configuration startup-configuration commands. While the copy run start command is interactive, the write command is not. In other words, write doesn't prompt to verify what you want to do. It's important to remember that the Cisco IOS Command Scheduler doesn't allow any interactive commands.
