Root password recovery from the console using recovery (single-user) mode

If nobody knows the root password and no other administrator account works, you can still regain control of a Junos device, but only with physical access to its console port. This is a deliberate design: the recovery procedure proves you are physically present, which is why console access and the room the device sits in must be protected. The exact prompts vary by platform and Junos generation, so treat this as the general flow and follow the documented procedure for your model.