Recover Passwords for Catalyst 4500/4900 Switches with Supervisor Engine

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Updated:October 31, 2023

Document ID:21229

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

Background Information

Configuration Process

Example Configuration and Output

Related Information

Introduction

This document describes how to recover a lost password on a Catalyst 4500/4900 switch that has a Supervisor Engine that runs Cisco IOS® Software.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific software and hardware versions.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Background Information

Note: In Catalyst 4500/4000 Series Switches, Supervisor Engines II+, II+10GE, II+TS, III, IV, V, and V-10GE support only Cisco IOS Software.

This document describes how to recover a lost or unknown password on a Catalyst 4500/4000 switch with a Supervisor Engine II-Plus (WS-X4013+), Supervisor Engine II-Plus-TS (WS-X4013+TS), Supervisor Engine II-Plus-10GE (WS-X4013+10GE), Supervisor Engine III (WS-X4014), Supervisor Engine IV (WS-X4515), Supervisor Engine V (WS-X4516), Supervisor Engine V-10GE (WS-X4516-10GE) module, Cisco Catalyst 4948, Cisco Catalyst 4948 10GE, and Cisco Catalyst 4900M switches.

Configuration Process

To recover your password on the Catalyst 4500/4900 switch:

Note: Ensure you have physical access to the switch and that you use console access to the Supervisor Engine module while you perform these steps. For details on the switch console connection, refer to Connect a Modem to the Console Port on Catalyst Switches.

Tip: Configuration of the switch is not lost if the procedure is followed as mentioned. As a best practice, Cisco recommends that you have a backup copy of the configuration of all Cisco devices at the TFTP server or a Network Management server.

Power cycle the device.

In order to power cycle, turn the device off, then back on.

Press Ctrl-C within 5 seconds to prevent autoboot. This action puts you in ROM monitor (ROMmon) prompt mode.


!--- Here, you power cycle the switch.

********************************************************** 
*                                                        * 
* Welcome to ROM Monitor for WS-X4014 System.            * 
* Copyright (c) 1999-2000, 2001 by Cisco Systems, Inc.   * 
* All rights reserved.                                   * 
*                                                        * 
**********************************************************
 
 ROM Monitor Program Version 12.1(10r)EY(1.21) 

 Board type 1, Board revision 7
 Swamp FPGA revision 16, Dagobah FPGA revision 43 
 
 Timer interrupt test passed.

 MAC Address  : 00-02-b9-83-af-fe 
 IP Address   : 172.16.84.122 
 Netmask      : 255.255.255.0 
 Gateway      : 172.16.84.1 
 TftpServer   : Not set. 
 Main Memory  : 256 MBytes


 ***** The system will autoboot in 5 seconds *****  Type control-C to prevent autobooting. 

!--- At this point, press Ctrl-C.  

Autoboot cancelled......... please wait!!! 
Autoboot cancelled......... please wait!!! 
rommon 1 > [interrupt] 

!--- The module ended in the ROMmon.  

rommon 1 > [interrupt]

Issue the confreg command at the rommon prompt.

Make the selections that appear here in boldface for password recovery:

rommon 1 > set

rommon 1 > confreg

 Configuration Summary : 
 => load ROM after netboot fails
 => console baud: 9600
 => autoboot from: commands specified in 'BOOT' environment variable

 do you wish to change the configuration? y/n  [n]:  y
 enable  "diagnostic mode"? y/n  [n]:  n
 enable  "use net in IP bcast address"? y/n  [n]:  n
 disable "load ROM after netboot fails"? y/n  [n]:  n
 enable  "use all zero broadcast"? y/n  [n]:  n
 enable  "break/abort has effect"? y/n  [n]:  n
 enable  "ignore system config info"? y/n  [n]:  y

 change console baud rate? y/n  [n]:  n

 change the boot characteristics? y/n  [n]:  n

 Configuration Summary : 
 => load ROM after netboot fails
 => ignore system config info
 => console baud: 9600
 => autoboot from: commands specified in 'BOOT' environment variable

 do you wish to save this configuration? y/n  [n]:   y 
 You must reset or power cycle for new configuration to take effect

Note: You can also use the confreg 0x2142 command at the ROMmon prompt in order to set the configuration register value to bypass the startup configuration stored in NVRAM.

rommon 1 > confreg 0x2142
You must reset or power cycle for the new configuration to take effect.

Issue the reset command so that the module reboots.

Due to the changes that you made in step 2, the module reboots but ignores the saved configuration.

rommon 2 > reset

Resetting ....... 

rommon 3 > 

********************************************************** 
*                                                        * 
* Welcome to ROM Monitor for WS-X4014 System.            * 
* Copyright (c) 1999-2000, 2001 by Cisco Systems, Inc.   * 
* All rights reserved.                                   * 
*                                                        * 
**********************************************************

!--- Output suppressed.  

Press RETURN to get started! 

!--- Press Return.  

00:00:21: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software 
IOS (tm) Catalyst 4000 L3 Switch Software (cat4000-IS-M), 
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Thu 24-Jan-02 17:34 by ccai
00:00:21: %SNMP-5-COLDSTART: SNMP agent on host Switch 
   is undergoing a cold start
Switch>

Make sure that the configuration register value is 0x2142.

This value makes the module boot from Flash without a load of the saved configuration. Issue the enable command at the Switch prompt to go to enable mode. Then, issue the show version command to check the configuration register value.

Switch>enable
Switch#show version
Cisco Internetwork Operating System Software 
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M),
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: https://www.cisco.com/tac
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Thu 24-Jan-02 17:34 by ccai
Image text-base: 0x00000000, data-base: 0x00AA2B8C

ROM: 12.1(10r)EY(1.21)
Switch uptime is 5 minutes
System returned to ROM by reload
Running default software 

cisco WS-C4006 (MPC8245) processor (revision 7) with 262144K bytes of memory. 
Processor board ID FOX04183666 
Last reset from Reload 
32 Gigabit Ethernet/IEEE 802.3 interface(s) 
467K bytes of non-volatile configuration memory. 

Configuration register is 0x2142 

Switch#

Issue the configure memory command or the copy startup-config running-config command to copy the NVRAM into memory.

Do not issue the configure terminal command, which shows the default configuration on the module.
```
Switch#configure memory

Uncompressed configuration from 1307 bytes to 3014 bytes
Switch#
00:13:52: %SYS-5-CONFIG_I: Configured from memory by console
c-4006-SUPIII#
```
Issue the show ip interface brief command to make sure that the interfaces that were in use earlier show an up/up status.

If any of the interfaces that were in use before the password recovery show down, issue the no shutdown command on that interface to bring the interface up.

Issue the write terminal command or the show running-config command to display the saved configuration on the module.

c-4006-SUPIII# show running-config   
Building configuration... 

Current configuration : 3014 bytes 
! 
version 12.1 
no service pad 
service timestamps debug uptime 
service timestamps log uptime 
no service password-encryption 
service compress-config 
! 
hostname c-4006-SUPIII 
! 
boot system flash bootflash: 
! 
vtp mode transparent 

!--- Output suppressed.  

line con 0
 stopbits 1
line vty 0 4
 login
! 
end 

c-4006-SUPIII#

Now you are ready to change the password on the module.

Issue these commands to change the password:

c-4006-SUPIII#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
c-4006-SUPIII(config)#no enable secret

!--- This step is necessary if the switch had an enable secret password.

c-4006-SUPIII(config)#enable secret < password > 
[Choose a strong password with at least one capital letter,
 one number, and one special character.]

!--- This command sets the new password.

Make sure that you change the configuration register value back to 0x2102.

Complete these steps at theconfigprompt to change and verify the configuration register value.

c-4006-SUPIII(config)#config-register 0x2102
c-4006-SUPIII(config)# ^Z
c-4006-SUPIII#
00:19:01: %SYS-5-CONFIG_I: Configured from console by console
c-4006-SUPIII#write memory 

!--- This step saves the configuration.

 Building  configuration... 
Compressed configuration from 3061 bytes to 1365 bytes[OK] 
c-4006-SUPIII#show version 

!--- This step verifies the value change.  

Cisco Internetwork Operating System Software 
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M), 
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: https://www.cisco.com/tac 
Copyright (c) 1986-2002 by cisco Systems, Inc. 
Compiled Thu 24-Jan-02 17:34 by ccai 
Image text-base: 0x00000000, database: 0x00AA2B8C 

ROM: 12.1(10r)EY(1.21) 
c-4006-SUPIII uptime is 20 minutes 
System returned to ROM by reload 
Running default software 

cisco WS-C4006 (MPC8245) processor (revision 7) with 262144K bytes of memory. 
Processor board ID FOX04183666 
Last reset from Reload 
32 Gigabit Ethernet/IEEE 802.3 interface(s) 
467K bytes of nonvolatile configuration memory. 

Configuration register is 0x2142 (will be 0x2102 at next reload) 

c-4006-SUPIII#

At this point, you have changed the password.

Example Configuration and Output

This example output is the result of the password recovery procedure on a Catalyst 4000 Supervisor Engine III.

c-4006-SUPIII> enable
Password: 
Password: 
Password: 
% Bad secrets 

!--- Here, you power cycle the switch.

********************************************************** 
*                                                        * 
* Welcome to ROM Monitor for WS-X4014 System.            * 
* Copyright (c) 1999-2000, 2001 by Cisco Systems, Inc.   * 
* All rights reserved.                                   * 
*                                                        * 
**********************************************************
 
 ROM Monitor Program Version 12.1(10r)EY(1.21) 

 Board type 1, Board revision 7
 Swamp FPGA revision 16, Dagobah FPGA revision 43 
 
 Timer interrupt test passed.

 MAC Address  : 00-02-b9-83-af-fe 
 IP Address   : 172.16.84.122 
 Netmask      : 255.255.255.0 
 Gateway      : 172.16.84.1 
 TftpServer   : Not set. 
 Main Memory  : 256 Mbytes


 ***** The system  will  autoboot in 5 seconds ***** 

Type control-C to prevent autobooting. 

!--- At this point, press Ctrl-C.  

Autoboot cancelled......... please wait!!! 
Autoboot cancelled......... please wait!!! 
rommon 1 > [interrupt] 

rommon 1 > [interrupt] 

rommon 1 > confreg 

Configuration Summary : 
=> load ROM after netboot fails 
=> console baud: 9600 
=> autoboot from: commands specified in 'BOOT' environment variable 

do you wish to change the configuration? y/n [n]: y 
enable "diagnostic mode"? y/n [n]: n 
enable "use net in IP bcast address"? y/n [n]: n 
disable "load ROM after netboot fails"? y/n [n]: n 
enable "use all zero broadcast"? y/n [n]: n 
enable "break/abort has effect"? y/n [n]: n 
enable "ignore system config info"? y/n [n]: y 

change console baud rate? y/n [n]: n 

change the boot characteristics? y/n [n]: n 

Configuration Summary : 
=> load ROM after netboot fails 
=> ignore system config info 
=> console baud: 9600 
=> autoboot from: commands specified in 'BOOT' environment variable 

do you wish to save this configuration? y/n [n]: y 
You must reset or power cycle for new configuration to take effect 

rommon 2 > reset 

Resetting ....... 

rommon 3 > 

********************************************************** 
*                                                        * 
* Welcome to ROM Monitor for WS-X4014 System.            * 
* Copyright (c) 1999-2000, 2001 by Cisco Systems, Inc.   * 
* All rights reserved.                                   * 
*                                                        * 
**********************************************************

ROM Monitor Program Version 12.1(10r)EY(1.21) 
Board type 1, Board revision 7 
Swamp FPGA revision 16, 
Dagobah FPGA revision 43 

Timer interrupt test passed. 

MAC Address : 00-02-b9-83-af-fe 
IP Address : 172.16.84.122 
Netmask : 255.255.255.0 
Gateway : 172.16.84.1 
TftpServer : Not set.
Main Memory : 256 Mbytes 

***** The system will autoboot in 5 seconds ***** 

Type control-C to prevent autobooting. 
. . . . . 

******** The system will autoboot now ******** 


config-register = 0x2142  
Autobooting using BOOT variable specified file..... 

Current BOOT file is --- bootflash: 

Rommon reg: 0x2B004180 
Decompressing the image : ########################### 
##################################################### 
####################################### [OK] 

k2diags version 1.6 

prod: WS-X4014 part: 73-6854-07 serial: JAB0546060Z 

Power-on-self-test for Module 1: WS-X4014 
Status: (. = Pass, F = Fail) 

Traffic using serdes loopback (L2; one port at a time)... 
switch port 0: . switch port 1: . switch port 2: . 
switch port 3: . switch port 4: . switch port 5: . 
switch port 6: . switch port 7: . switch port 8: . 

!--- Output suppressed.  

Module 1 Passed 


Exiting to ios... 

Rommon reg: 0x2B000180 
Decompressing the image : ########################## 

!--- Output suppressed.  

######################################################### [OK] 

              Restricted Rights Legend  

Use, duplication, or disclosure by the Government is 
subject to restrictions as set forth in subparagraph 
(c) of the Commercial Computer Software - Restricted 
Rights clause at FAR sec. 52.227-19 and subparagraph 
(c) (1) (ii) of the Rights in Technical Data and Computer 
Software clause at DFARS sec. 252.227-7013. 

           cisco Systems, Inc.
           170 West Tasman Drive
           San Jose, California 95134-1706



Cisco Internetwork Operating System Software 
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M),
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Thu 24-Jan-02 17:34 by ccai
Image text-base: 0x00000000, database: 0x00AA2B8C


cisco WS-C4006 (MPC8245) processor (revision 7) with 262144K bytes of memory. 
Processor board ID FOX04183666 
Last reset from Reload 
32 Gigabit Ethernet/IEEE 802.3 interface(s) 
467K bytes of nonvolatile configuration memory. 


Press RETURN to get started! 

00:00:21: %SYS-5-RESTART: System restarted -- 
Cisco Internetwork Operating System Software
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M),
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: https://www.cisco.com/tac 
Copyright (c) 1986-2002 by cisco Systems, Inc. 
Compiled Thu 24-Jan-02 17:34 by ccai 
00:00:21: %SNMP-5-COLDSTART: SNMP agent on host Switch is undergoing a cold start 

Switch>enable 
Switch#show version 
Cisco Internetwork Operating System Software 
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M), 
Version 12.1(8a)EW, RELEASE SOFTWARE (fc1) 
TAC Support: https://www.cisco.com/tac 
Copyright (c) 1986-2002 by cisco Systems, Inc. 
Compiled Thu 24-Jan-02 17:34 by ccai 
Image text-base: 0x00000000, database: 0x00AA2B8C 

ROM: 12.1(10r)EY(1.21) 
Switch uptime is 5 minutes 
System returned to ROM by reload 
Running default software 

cisco WS-C4006 (MPC8245) processor (revision 7) with 262144K bytes of memory. 
Processor board ID FOX04183666 
Last reset from Reload 
32 Gigabit Ethernet/IEEE 802.3 interface(s) 
467K bytes of nonvolatile configuration memory. 

Configuration register is 0x2142 

Switch# 

Switch#configure memory 

Uncompressed configuration from 1307 bytes to 3014 bytes 
c-4006-SUPIII# 
00:13:52: %SYS-5-CONFIG_I: Configured from memory by console 
c-4006-SUPIII#show running-config  
Building configuration... 

Current configuration : 3014 bytes 
! 
version 12.1 
no service pad 
service timestamps debug uptime 
service timestamps log uptime 
no service password-encryption 
service compress-config 
! 
hostname c-4006-SUPIII 
! 
boot system flash bootflash: 
! 
vtp mode transparent 
!
vlan 20
  private-vlan primary
!
vlan 100
!
vlan 202
  private-vlan association 440
!         
vlan 440
  private-vlan isolated
!
vlan 500
ip subnet-zero
no ip domain-lookup
!
ip multicast-routing
!
!
interface GigabitEthernet1/1
 no switchport
 ip address 10.1.1.1 255.255.255.0
 ip pim dense-mode
!
interface GigabitEthernet1/2
 no switchport
 ip address 10.2.2.2 255.255.255.0
! 

!--- Output suppressed.  

! 
interface Vlan1
 ip address 172.16.84.140 255.255.255.0
 ip pim dense-mode
!
interface Vlan2
 no ip address
 shutdown
!
interface Vlan20
 no ip address
 shutdown
! 

!--- Output suppressed.  

! 
line con 0
 stopbits 1
line vty 0 4
 login
! 
end 

c-4006-SUPIII#configure terminal  
Enter configuration commands, one per line. End with CNTL/Z. 
c-4006-SUPIII(config)#no enable secret

!--- This step is necessary if the switch had an enable secret password. 

c-4006-SUPIII(config)#enable secret < password >
[Choose a strong password with at least one capital letter, 
one number, and one special character.] 
c-4006-SUPIII(config)#config-register 0x2102 
c-4006-SUPIII(config)#^Z 
c-4006-SUPIII#write memory 
Building configuration... 
Compressed configuration from 3061 bytes to 1365 bytes[OK] 
c-4006-SUPIII#show version 
Cisco Internetwork Operating System Software 
Cisco IOS (TM) Catalyst 4000 L3 Switch Software (cat4000-IS-M), 
   Version 12.1(8a)EW,  RELEASE SOFTWARE (fc1)
TAC Support: https://www.cisco.com/tac 
Copyright (c) 1986-2002 by cisco Systems, Inc. 
Compiled Thu 24-Jan-02 17:34 by ccai 
Image text-base: 0x00000000, database: 0x00AA2B8C 

ROM: 12.1(10r)EY(1.21) 
c-4006-SUPIII uptime is 20 minutes 
System returned to ROM by reload 
Running default software 

cisco WS-C4006 (MPC8245) processor (revision 7) with 262144K bytes of memory. 
Processor board ID FOX04183666 
Last reset from Reload 
32 Gigabit Ethernet/IEEE 802.3 interface(s) 
467K bytes of nonvolatile configuration memory. 

Configuration register is 0x2142 (will be 0x2102 at next reload) 

c-4006-SUPIII#

Related Information

Revision History

Revision	Publish Date	Comments
2.0	31-Oct-2023	Recertification
1.0	13-Mar-2002	Initial Release

Contributed by Cisco Engineers

Julio Jimenez
Cisco TAC Engineer

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This Document Applies to These Products

Catalyst 4500 Series Switches

Recover Passwords for Catalyst 4500/4900 Switches with Supervisor Engine

Available Languages

Download Options

Bias-Free Language

Contents

Introduction

Prerequisites

Requirements

Components Used

Conventions

Background Information

Configuration Process

Example Configuration and Output

Related Information

Revision History

Contributed by Cisco Engineers

Was this Document Helpful?

Contact Cisco

This Document Applies to These Products