In today’s network, just about every network device you are working with is remote to where you are. located. When making some types of changes to network devices, you always run the risk that the change may cause the device to go unreachable, which then triggers an uncomfortable series of events to get the device back online.
Bringing the device back online may require you to do one of the following:
- Contact someone at the remote site to go to the device and power it off/on to restore the configuration to its state before you made the change. If you are doing this change off-hours, this might mean waiting until someone comes back in the office.
- Activate your remote hands support and roll a truck/resource to the site to do the work for you. This usually comes at a cost to get a resource on-site to assist.
- In some cases, based on when you saved your changes during your work, this might require the resource to have a laptop/console cable to connect to the console port to help you backout your change.
But there is a much safer way to handle risky changes like these. Cisco’s IOS operating systems gives us a great solution.
Backup your Running-Configuration to Startup-Configuration
Before making any changes, do a copy running-configuration startup-configuration to make sure you have your “known good” configuration saved to your startup-configuration/nvram.
Schedule a reboot in the future
Use the following command to schedule a reboot in the future:
Lab-Router#reload in 10This command will schedule a reboot in 10 minutes. The count-down timer starts the minute to hit enter. Make sure you give yourself enough time to make and test the change. If you are doing this during the day and are worried about how long of an outage you might create if you have an issues, you might want to reduce the amount of time to the scheduled reboot.
Make your configuration changes
Proceed to make your network configuration changes and test them. Make sure that they have the intended result. Once you have verified that the configuration changes are complete and you have not negatively impacted the devices you can cancel the scheduled reload.
Cancel the scheduled reload
LabRouter#reload cancelNow that you know your change worked, you should also take the time to save your successful change to the startup configuraiton.
Save your successful configuration
LabRouter#copy running-configuration startup-configurationWhat happens if your change causes the device to drop off the network?
Not to worry, go grab a cub of coffee and just wait for the scheduled reload to reboot the device and it will come back online with the configuration that you saved before you started to make network changes.
Once the device comes back online, you can take the time to review your configuration change, what went wrong, and plan to try again.
Other ways to schedule a reload
Cisco IOS also gives you some other ways to schedule a reload in the future. Rather than specifying a number of minutes to reload in, your can specify a time to reload:
Lab-Router#reload at 3:00This will schedule a reload at 3:00 am. Keep in mind that this is going to schedule the reboot at 3:00 am based on the time in this network devices clock. This would be a great time to make sure this device is syncing to an NTP server. How to configure NTP on a Cisco IOS device
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