Cisco

Cisco Catalyst 4500 / 6500 Switch Password Recovery

Recover a lost enable password on Catalyst 4500/4500-X/6500/6800 modular switches using ROMMON and the config-register bypass.

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

Catalyst 4500/6500/6800 modular switches use ROMMON and the standard IOS config-register bypass. On dual-supervisor chassis, recover on the supervisor you want to remain active.

Prerequisites

Recovery Steps

  1. Connect the console and power-cycle the chassis.
  2. Send the Break sequence during boot to reach rommon 1 >.
  3. Set the configuration register to bypass the startup config:
    rommon 1 > confreg 0x2142
    rommon 2 > reset
  4. After boot, merge the saved configuration back:
    Switch> enable
    Switch# copy startup-config running-config
  5. Set the new password:
    Switch(config)# enable secret <new-password>
  6. Restore the register, save and reload:
    Switch(config)# config-register 0x2102
    Switch(config)# end
    Switch# write memory
    Switch# reload