Disclaimer: The author and Cisco Press are not liable for any damage to routers when using this feature. Please use this feature with extreme caution, and read all related materials and the following recovery procedure.
The 2600/3600 series (and newer versions of ROMMON for the 1700 series) all have what is known as a “ROMMON security” feature.
ROMMON security is designed to prevent a person with physical access to the router (2600 or 3600) from viewing the configuration file.
ROMMON security disables access to the ROMMON so that a person cannot set the configuration register to ignore the startup configuration. See the example that follows:
Router(config)#no service password-recovery ...