Cisco Configuration Archive & Rollback: Using revert Instead of reload

Managing configuration changes on Cisco devices, especially when working remotely, can be challenging.

Traditionally, administrators have used the reload in command to schedule a device reboot, providing a safety net to revert to a previous configuration if something goes wrong.

However, Cisco’s Configuration Archive and Rollback feature offers a more efficient and less disruptive method: the revert command.

Setting Up Configuration Archiving

To utilize the rollback feature, you first need to enable configuration archiving and specify a storage location for the archived configurations. This can be done by entering global configuration mode and defining the archive path:

The path command supports various storage options, including local flash memory, FTP, HTTP, and SCP. Using local flash storage is often preferred to avoid potential connectivity issues with external repositories.

After configuring the archive path, you can verify the setup with the show archive command.

Implementing the Revert Timer

With archiving enabled, you can set a revert timer before making configuration changes.

This timer specifies a period (ranging from 1 to 120 minutes) after which, if not canceled, the device will automatically roll back to the previous configuration.

To set a 1-minute revert timer and change the device hostname:

Router# configure terminal revert timer 1

Router(config)# hostname NewHostname

NewHostname(config)# end

NewHostname#

If the timer expires without confirmation, the device reverts to its prior configuration, undoing any changes made during that period.

Managing the Revert Timer

To check the remaining time on the revert timer, use:

Router# show archive config rollback timer

If you need more time to complete your changes, you can reset the timer:

Router# configure revert timer <new_time_in_minutes>

This command restarts the timer with the specified duration.

Manually Rolling Back Changes

If you decide to revert to the previous configuration before the timer expires, execute:

Router# configure revert now

This command immediately rolls back all changes made since the revert timer was set.

Confirming and Saving Changes

Once you’re satisfied with the new configuration and want to retain it, cancel the rollback process:

Router# configure confirm

This command stops the revert timer, ensuring your changes remain active. Remember, this action does not save the configuration to the startup configuration. To make the changes persistent across reboots, use:

Router# write memory

Considerations

While the revert feature is powerful, it’s essential to test it in a controlled environment before deploying it in production.

Some users have reported issues where the revert timer did not cancel as expected, leading to unintended rollbacks.

Additionally, this feature affects only the running configuration. If you save changes to the startup configuration but allow the revert timer to expire, the running configuration will revert, but the startup configuration will retain the new changes.