Faraway routers can be safely configured by using a reload command first. If the router becomes unreachable as a result of a typo or other misconfiguration, you need only wait, and the router will reload itself to the saved configuration permitting you to try, try again.
Before any configuration changes are made, issue a reload command to the remote router. This command instructs the router to reboot in 30 minutes:
reload in 30
Use this command to reload at a specific time.
reload at 00:00
Proceed to configure the router as needed. As long as no configuration changes are saved, the router will revert to its previous configuration when it reloads.
If configuration changes are successful, this code will stop the pending reload:
If configuration changes cause a loss of connectivity, the local side can be easily reset to the previous configuration. When the router reloads, connectivity will be restored.