Cisco password recovery
This is compressed process of Password Recovery Procedure for the Cisco 1700 and 1800 Series Routers for Cisco 1841 router.
- Console to the router with Tetra Term and send Break (alt+b) at POST. Literally power off/on and send break straight after 2 seconds or when you see the first lines of booting messages.
rommon 1 > confreg 0x2142 You must reset or power cycle for new config to take effect rommon 2 > reset
- Answer No or press ctrl+c to skip auto configuration
- Type enable>
- Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.
- Type configure terminal
- Type enable secret <password> in order to change the enable secret password
- Issue the no shutdown command on every interface that you use.
- Type config-register <configuration_register_setting>. Where configuration_register_setting is either the value you recorded or 0x2102
- Type end and write memory or copy running-config startup-config to save changes
- Type reload
The configuration register tells the router how to boot. There are many possible settings for the configuration register. The most common ones are:
- 0x2102 - Factory default setting for Cisco routers (load the IOS image from flash and load the startup config file from NVRAM)
- 0x2142 - Router ignores the contents of Non-Volatile RAM (NVRAM)
- 0x2120 - Router boots into ROMmon mode