Cisco

Cisco ISR and ASR Router Password Recovery

Recover a lost enable password on Cisco ISR and ASR routers using the config-register 0x2142 procedure over the console port.

Overview

This guide provides step-by-step instructions for resetting lost or forgotten administrative passwords on enterprise networking hardware. Follow the procedure below carefully to regain access while preserving your device configuration.

Prerequisites

Before proceeding with password recovery, ensure you have a console cable, terminal emulation software configured to 9600 baud, and physical access to the device.

Step 1: Establish Console Connection

Connect your terminal cable to the console port of the device and open your serial terminal session.

Step 2: Interrupt the Boot Sequence

Power cycle the hardware and issue a Break key sequence during initial system startup to enter ROMMON mode.

Step 3: Reset Password & Configuration

Bypass startup configuration loading, boot into system software, set your new credentials, and save changes back to non-volatile memory.

Overview

ISR and ASR platforms use the standard Cisco IOS/IOS-XE password-recovery procedure: boot with the configuration register set so the router ignores its startup configuration, set a new password, then restore.

Prerequisites

Recovery Steps

  1. Connect the console and power-cycle the router.
  2. Within the first 60 seconds send the Break sequence to reach rommon 1 >.
  3. Bypass the startup configuration:
    rommon 1 > confreg 0x2142
    rommon 2 > reset
  4. After boot, answer no to the setup dialog, then merge the saved configuration back:
    Router> enable
    Router# copy startup-config running-config
  5. Set the new password:
    Router(config)# enable secret <new-password>
  6. Restore the register, save and reload:
    Router(config)# config-register 0x2102
    Router(config)# end
    Router# write memory
    Router# reload

Note

On IOS-XE platforms that load packages.conf, use boot flash:packages.conf at the rommon prompt if a plain reset does not boot.