The configuration register is a 16-bit software register that controls boot settings and the startup configuration for routers. To recover the password, the router must be power cycled and the break sequence entered within 60 seconds to access Rommon mode, where the configuration register can be set to 0x2142 to boot without the NVRAM configuration and allow changing the password.

1. Password Recovery:-
• Configuration register: 16 bit software register
which controls the boot sequence, the console
speed ,IP broadcast, startup configuration settings,
etc
• Default setting on the configuration register is
NVRAM-0x2102

2. Procedure for Password
Recovery:-
• Password recovery can be done only through the
console port
• Power cycle the router and within the first 60
seconds of booting hit the break sequence (CTRL
+BREAK – for Windows 95 and 98)
• The router goes into Rommon mode which looks
like “ >” or “rommon >” depending on the series
of the router

3. Changing the configuration
register:-
• > o/r 0x2142
• i
OR
• rommon> confreg 0x2142
• rommon> reset
• The router now boots without the configuration in
NVRAM and the password can be changed