Cisco Router Password Recovery … The Easy Way
1. Ensure that minicom/hyperterminal window is connected to the router that needs to be
configured.
Linux> sudo minicom ttyS0
or
Linux> sudo minicom ttyS1
2. Unplug the power cord from the power strip outside the router rack. (Starting from the
LED switch end, routers are connected in sequential order.)
3. Plug in the power cord for a router.
4. When you see
System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1)
Copyright (c) 2000 by cisco Systems, Inc.
C2600 platform with 32768 Kbytes of main memory
program load complete, entry point: 0x80008000, size: 0x761444
Self decompressing the image : ################
Send the break signal. For hyperterminal, it may be achieved by the key sequence ctrlbreak, function-break, or something else. For minicom, you may use ctrl-a followed by
‘z’ followed by ‘f’ (without the quotes).
5. You will see the following prompt.
...
monitor: command "boot" aborted due to user interrupt
rommon 1 >
6. Type
rommon 1 > confreg 0x2142
You must reset or power cycle for new config to take effect
rommon 2 > reset
7. The router reboots, and, eventually, you will see
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.3(22), RELEASE
SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by cisco Systems, Inc.
Compiled Wed 24-Jan-07 16:48 by ccai
Image text-base: 0x80008098, data-base: 0x80CEA424
cisco 2621 (MPC860) processor (revision 0x600) with 28672K/4096K
bytes of memory.
Processor board ID JAD06020ND6 (3352753447)
M860 processor: part number 0, mask 49
Original date: 4/24/07. Revised on 3/27/09 © Rajendra V. Boppana
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Bridging software.
X.25 software, Version 3.0.0.
2 FastEthernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read/Write)
--- System Configuration Dialog --Would you like to enter the initial configuration dialog?
[yes/no]:
8. Enter no for the last question.
9. You will see a lot of text and finally
Router>
10. The text in bold is what you need to do.
Router>en
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname Router2
Router2(config)#no ip domain-lookup
Router2(config)#enable secret cisco
Router2(config)#line console 0
Router2(config-line)#exec-timeout 0 0
Router2(config-line)#logging synchronous
Router2(config-line)#password cisco
Router2(config-line)#login
Router2(config-line)#end
Router2#
*Mar 1 00:02:40.479: %SYS-5-CONFIG_I: Configured from console by
console
Router2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router2(config)#line vty 0 4
Router2(config-line)#password cisco
Router2(config-line)#login
Router2(config-line)#end
Router2#
*Mar 1 00:07:09.479: %SYS-5-CONFIG_I: Configured from console by
console
Router2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router2(config)#config-register 0x2102
Router2(config)#end
Router2#
*Mar 1 00:08:37.751: %SYS-5-CONFIG_I: Configured from console by
console
Router2#copy running-config startup-config
Destination filename [startup-config]? {Enter}
Building configuration...
Original date: 4/24/07. Revised on 3/27/09 © Rajendra V. Boppana
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[OK]
Router2#reload
Proceed with reload? [confirm]
{Enter}
11. After rebooting, press enter. You will be asked for a password. Use the console password
to login. Type ‘enable’ and provide the secret password when prompted. You will enter
the privileged mode. Use ‘sh conf’ command to see the current configuration. The
output should be similar to the text given below.
Using 672 out of 29688 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router2
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$R7i1$M3/GawERxPx7YnaRPfj2F/
!
no aaa new-model
ip subnet-zero
ip cef
!
!
no ip domain lookup
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0
no ip address
shutdown
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
no ip http server
Original date: 4/24/07. Revised on 3/27/09 © Rajendra V. Boppana
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ip classless
!
!
!
!
!
line con 0
exec-timeout 0 0
password cisco
logging synchronous
login
line aux 0
line vty 0 4
password cisco
login
!
!
end
Original date: 4/24/07. Revised on 3/27/09 © Rajendra V. Boppana
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