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Cisco Nexus 5000/6000 Password Recovery

Complete procedure for recovering the admin password on Cisco Nexus 5000 and 6000 series switches.

Prerequisites

Item Details
Console Cable DB9 serial console cable (USB console will NOT work)
Terminal Software PuTTY, TeraTerm, or similar
Console Settings 9600 baud, 8 data bits, 1 stop bit, no parity
Keyboard Layout EN-US recommended (for break sequence)

USB Console Not Supported

Password recovery requires a DB9 serial console connection. USB console cables will not work for the break sequence.

Break Sequence Reference

Keyboard Break Sequence Notes
US English Ctrl+] Hold Ctrl, press ]
German (US layout) Ctrl++ Strg + the + * ~ key
German (native) ++ctrl+alt-gr+9++ Works through Opengear
Older NX-OS (4.0) Ctrl+B Ctrl+Shift+B on some

Password Recovery Procedure

Part 1: Access Boot Mode

  1. Connect console cable to the switch's DB9 serial port
  2. Open terminal session with settings: 9600-8-N-1
  3. Power on (or power cycle) the switch
  4. Watch for the boot sequence messages
  5. When you see: Checking all filesystems....r. done.
  6. Immediately press the break sequence (Ctrl+])
  7. You should see the switch(boot)# prompt

Timing is Critical

The break sequence window is short. Press it as soon as you see "Checking all filesystems" - don't wait for it to complete.

Part 2: Reset Admin Password

# Enter configuration mode
switch(boot)# configure terminal

# Set new admin password
switch(boot-config)# admin-password YourNewPassword123

# Exit configuration mode
switch(boot-config)# exit

Part 3: Boot the System

# List available images
switch(boot)# dir bootflash:

# Boot the system image (example filename)
switch(boot)# load bootflash:n5000-uk9.5.1.3.N2.1b.bin

Part 4: Verify and Save

# Login with new credentials
Username: admin
Password: YourNewPassword123

# Verify you're logged in
switch# show users

# Save the configuration
switch# copy running-config startup-config

Optional: Factory Reset

If you want to completely reset the switch after password recovery:

# Erase all configuration
switch# write erase

# Reload the switch
switch# reload

# After reboot, save clean config
switch# copy running-config startup-config

Quick Reference Commands

Command Purpose
dir bootflash: List boot images
load bootflash:<image> Boot specific image
admin-password <pass> Set admin password (boot mode only)
show version Display NX-OS version
show users Show logged-in users
write erase Erase startup configuration
copy run start Save running config

Troubleshooting

Break Sequence Not Working

  • Verify using DB9 serial port, not USB console
  • Try different break sequences (see table above)
  • Check terminal settings are exactly 9600-8-N-1
  • Ensure EN-US keyboard layout is active
  • Try pressing break sequence repeatedly during boot

Cannot Find Boot Image

# List all files in bootflash
switch(boot)# dir bootflash:

# If empty, check USB
switch(boot)# dir usb1:
switch(boot)# dir usb2:

Password Still Not Working After Reset

  • Password recovery only updates the local user database
  • Remote AAA authentication will still use old credentials
  • Ensure local authentication is enabled: 
    switch# show aaa authentication

SNMP Community String

After password recovery, update SNMP if needed: 

switch# configure terminal
switch(config)# snmp-server community <string> ro

Important Notes

Service Disruption

Password recovery requires a reboot. Schedule a maintenance window as all traffic will be disrupted.

Local Authentication Only

The recovered password only works for local authentication. Remote AAA servers retain their original credentials.

References