How many times have you locked yourself out of your device? In my professional career, this happened to me several times when I was either configuring AAA or making any routing related changes. Usually, the reason for this is the human error associated with invalid configuration. Some vendors offer a commit model that allows you to apply the configuration and then save it to the system by committing the change. As we know not all vendors offer the commit model approach and when a change is introduced in the system, such a change is pushed immediately. This approach means that sometimes, as a result of an erroneous change, we may lose access to the device, create loops, shutdown the interface we didn’t want, etc. In such a situation, we often have to use the console to gain access back to the device, if we have one, in the worst case, if the configuration has not been saved to the device, we can ask someone who has physical access to the device to reboot the device.