部分Cisco路由器口令的恢复

Contents

Description
Step-by-Step Procedure

Related Information

This document describes the password recovery procedure for the following Cisco products:

Step-by-Step Procedure

Attach a terminal or PC with terminal emulation to the console port of the router. Use the following terminal settings:

9600 baud rate
No parity
8 data bits
1 stop bit
No flow control

The required console cable specifications are described in the Cabling Guide for RJ-45 Console and AUX Ports (Cisco's 1000 series, 2500 series, and AS5100).

1. Type show version and record the setting of the configuration register. Click here to see output of a show version command.

   The configuration register setting is usually 0x2102 or 0x102.

2. Using the switch, turn off the router and then turn it on.
3. Press Break on the terminal keyboard within 60 seconds of the powerup to put the router into ROMMON.
4. Type o/r 0x2142 at the > prompt to boot from Flash without loading the configuration.
5. Type i at the > prompt.

   The router reboots but ignores its saved configuration.

6. Type no after each setup question or press Ctrl-C to skip the initial setup procedure.
7. Type enable at the Router> prompt.

   You'll be in enable mode and see the Router# prompt.

8. Important Type config mem or copy start running to copy the nonvolatile RAM (NVRAM) into memory. Do not type config term.
9. Type wr term or show running.

   The show running and wr term commands show the configuration of the router. In this configuration you see under all the interfaces the shutdown command, which means all interfaces are currently shutdown. Also, you can see the passwords either in encrypted or unencrypted format.

10. Type config term and make the changes.

    The prompt is now hostname(config)#.

11. Type enable secret <password>.
12. Issue the no shutdown command on every interface that is used. If you issue a show ip interface brief command, every interface that you want to use should be "up up".
13. Type config-register 0x2102, or the value you recorded in step 2.
14. Press Ctrl-z to leave the configuration mode.

    The prompt is now hostname#.

15. Type write mem or copy running startup to commit the changes.

Example of Password Recovery on a Cisco 2500

The example shown here is password recovery on a Cisco 2500.

Router>en
Password:
Password:
Password:
% Bad secrets

Router>show version
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(7)T,  RELEASE SOFTWARE (fc2)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 06-Dec-99 17:10 by phanguye
Image text-base: 0x0306C4E0, data-base: 0x00001000

ROM: System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE
BOOTFLASH: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fc1)

Router uptime is 5 minutes
System returned to ROM by power-on
System image file is "flash:/c2500-js-l.120-7.T"

cisco 2500 (68030) processor (revision D) with 8192K/2048K bytes of memory.
Processor board ID 02315272, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
1 Ethernet/IEEE 802.3 interface(s)
1 Token Ring/IEEE 802.5 interface(s)
2 Serial network interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read ONLY)

Configuration register is 0x2102
Router>

!--- The router was just powercycled and during bootup a
!--- break sequence was sent to the router.
!

Abort at 0x10EA83C (PC)
>o/r 0x2142
>i

System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE
Copyright (c) 1986-1995 by cisco Systems
2500 processor with 8192 Kbytes of main memory

F3: 13626872+197596+780568 at 0x3000060

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
IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(7)T,  RELEASE SOFTWARE (fc2)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 06-Dec-99 17:10 by phanguye
Image text-base: 0x0306C4E0, data-base: 0x00001000

cisco 2500 (68030) processor (revision D) with 8192K/2048K bytes of memory.
Processor board ID 02315272, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
1 Ethernet/IEEE 802.3 interface(s)
1 Token Ring/IEEE 802.5 interface(s)
2 Serial network interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read ONLY)

--- System Configuration Dialog ---

Would you like to enter the initial configuration dialog? [yes/no]:
!--- Ctrl-C pressed
!

Press RETURN to get started!

00:00:08: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up
00:00:08: %LINK-3-UPDOWN: Interface Serial0, changed state to up
00:00:08: %LINK-3-UPDOWN: Interface Serial1, changed state to up
00:00:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up
00:00:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
00:01:29: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up
00:01:29: %LINK-3-UPDOWN: Interface Ethernet0Translating "Router"...domain server (255.255.255.255)
, changed state to up
00:01:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
00:01:31: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(7)T,  RELEASE SOFTWARE (fc2)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 06-Dec-99 17:10 by phanguye
00:01:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down
00:01:33: %LINK-5-CHANGED: Interface Ethernet0, changed state to administratively down
00:01:33: %LINK-5-CHANGED: Interface Serial0, changed state to administratively down
00:01:33: %LINK-5-CHANGED: Interface Serial1, changed state to administratively down
00:01:33: %LINK-5-CHANGED: Interface TokenRing0, changed state to administratively down
00:01:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to down
00:01:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
00:01:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface TokenRing0, changed state to down
Router>en
Router#copy start run
Destination filename [running-config]?

1278 bytes copied in 10.448 secs (127 bytes/sec)
Router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#enable secret Cisco
Router(config)#int e0
Router(config-if)#no shut
*Mar  1 00:04:12.863: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up
*Mar  1 00:04:13.947: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up
Router(config-if)#int s0
Router(config-if)#no shut
*Mar  1 00:04:18.107: %LINK-3-UPDOWN: Interface Serial0, changed state to up
*Mar  1 00:04:19.167: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up
Router(config-if)#int s1
Router(config-if)#no shut
Router(config-if)#
*Mar  1 00:04:27.055: %LINK-3-UPDOWN: Interface Serial1, changed state to up
*Mar  1 00:04:28.071: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
Router(config-if)#exit
Router(config)#config-register 0x2102
Router(config)#^Z
Router#wr mem
*Mar  1 00:05:09.035: %SYS-5-CONFIG_I: Configured from console by console
Building configuration...
[OK]
Router#
Router#