In network engineering, configuring a production device can be a high-stakes operation. One wrong command could cause a cascade of network issues or potentially cut off access to the device. This becomes an even more significant issue when no Out of Band (OOB) management access is set up.
Fortunately, Cisco provides a nifty command to serve as a safety net for such scenarios: the reload command.
The Reload Command
Normally, if you issue the reload command on a Cisco device without additional parameters, it will immediately restart the device.
Router# reload
However, if you have made some configuration changes and lost connection to the device, this command won’t help. The changes you’ve made might not be saved, and the device might not return to the state you expect, exacerbating the situation.
The Reload In Command
Using the reload in command is a safer approach. This command schedules a device to reload after a specified amount of time.
For example, you might use the command reload in 10, which would schedule the device to reload in 10 minutes.
Router# reload in 10
Now, you can safely make your changes. If everything works as expected, you can cancel the scheduled reload with the `reload cancel` command.
Router# reload cancel
However, if something goes wrong and you lose access, the device will automatically revert to its previous state after the scheduled reload time.
Remember, this safety net is not foolproof. If you save a problematic configuration before realizing there’s an issue, the device will reload with that configuration.
Always Plan for OOB Management
While the reload in command provides a solid safety net, nothing can replace proper OOB management access for critical devices. An OOB network can provide an alternative access path to the device if the primary connection is lost.
Regardless of your safety measures, nothing is as valuable as careful planning and thorough testing. Always aim to test changes in a controlled environment before deploying them in production, and only save configurations when you’re confident they’re working correctly.