You can use PuTTY to send a Special Command such as Break when entering ROMMON mode in a Cisco router. Just right-click on the top area > Special Command > Break.
Refer to this Cisco link in performing a password recovery in a Cisco ASR920 router. You can use the Break key or in some cases Ctrl+Break key combo to get into ROMMON mode.
- Use the power switch to turn off the router and then turn it on again.
- Press Break on the terminal keyboard within 60 seconds of power up to put the router into ROMMON. In some cases Ctrl+Break key combination can be used.
- Type confreg 0x2142 at the ROMMON.
rommon1> confreg 0x2142
rommon1>sync
The router reboots, but ignores the saved configuration. - The router will reload and prompt for configuration.Type no after each setup question, or press Ctrl-C to skip the initial setup procedure.
- Type enable at the Router>
prompt.
You are now in enable mode and should see the Router# prompt. - Reset the
config-register from 0x2142 to 0x2102. To do so, type the following:
config-register configuration_register_setting
Where, configuration_register_setting is 0x2102. For example,
(config)# config-register 0x2102
