How to Reset The Admin Password On A Cisco Router

Written by: rapture Published by: Nightscript Published on: 2004-12-16 11:34:33 Topic: Networking

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This guide describes the procedure for recovering an enable password or enable secret passwords. These passwords are used to protect access to privileged EXEC and configuration modes. The enable password password can be recovered but the enable secret password is encrypted and can only be replaced with a new password.

How to Reset The Admin Password On A Cisco Router (Local) By Rapture This is the first in my series of guides to cisco routers. Cisco border routers are what seperates the internal network from the internet. It is important to understand how they work, because an insecure border router means an insecure network. Please email me any ideas about cisco related guides you would like to read about, my next article will be a guide to hardening the security of Cisco routers. Introduction This guide describes the procedure for recovering an enable password or enable secret passwords. These passwords are used to protect access to privileged EXEC and configuration modes. The enable password password can be recovered but the enable secret password is encrypted and can only be replaced with a new password. Requirements Physical access to the router Basic cisco experience PC with hyperterminal RJ-45 rollover cable Step-by-Step Procedure 1. Attach a terminal or PC with terminal emulation (such as hyperterminal) 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 For additional information on cabling and connecting a terminal to the console port or the AUX port, refer to the following documents Cabling Guide for Console and AUX Ports on Cisco Routers - http://www.cisco.com/warp/public/701/14.html 2. Using the power switch, turn off the router and then turn it back on. 3. Press Break on the terminal keyboard within 60 seconds of the power-up to put the router into ROMMON Example: *** System received an abort due to Break Key *** signal= 0x3, code= 0x500, context= 0x813ac158 PC = 0x802d0b60, Vector = 0x500, SP = 0x80006030 rommon 1 > 4. Type confreg 0x2142 at the rommon 1> prompt to boot from Flash without loading the configuration. Example: rommon 1 > confreg 0x2142 You must reset or power cycle for new config to take effect 5. Type reset at the rommon 2> 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. Example: --- System Configuration Dialog --- Would you like to enter the initial configuration dialog? [yes/no]: n Press RETURN to get started! 7. Type enable at the Router> prompt. You'll be in enable mode and see the Router# prompt. Example: Router>enable Router# 8. Type copy startup-config running-config to copy the nonvolatile RAM (NVRAM) into memory. Example: Router#copy startup-config running-config Destination filename [running-config]? 1324 bytes copied in 2.35 secs (662 bytes/sec) Router# 00:01:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:1, changed state to down 00:01:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:2, changed state to down 9. Type show running-config. The show running-config command shows 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 (enable password, enable secret, vty, console passwords, and so on) either in encrypted or unencrypted format. The unencrypted passwords can be re-used, the encrypted ones will have to be changed with a new one. 10. Type configure terminal and to make the changes. The prompt is now hostname(config)#. 11. Type enable secret <password> to change the enable secret password. Example: Router(config)#enable secret cisco 12. Issue the no shutdown command on every interface that is used. (To find out what interfaces are available, issue a "show ip interface brief" command) Example : Router(config)#show ip interface brief Interface IP-Address OK? Method Status Protocol Ethernet0/0 10.200.40.37 YES TFTP administratively down down Serial0/0 unassigned YES TFTP administratively down down BRI0/0 193.251.121.157 YES unset administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down Ethernet0/1 unassigned YES TFTP administratively down down Serial0/1 unassigned YES TFTP administratively down down Loopback0 193.251.121.157 YES TFTP up up Router(config)#interface Ethernet0/0 Router(config-if)#no shutdown Router(config-if)# 00:02:14: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up 00:02:15: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0, changed state to up Router(config-if)#interface BRI0/0 Router(config-if)#no shutdown Router(config-if)# 00:02:26: %LINK-3-UPDOWN: Interface BRI0/0:1, changed state to down 00:02:26: %LINK-3-UPDOWN: Interface BRI0/0:2, changed state to down 00:02:26: %LINK-3-UPDOWN: Interface BRI0/0, changed state to up 00:02:115964116991: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0, TEI 68 changed to up Router(config-if)#^Z <------ Control + Z Router# 00:02:35: %SYS-5-CONFIG_I: Configured from console by console Now check the interfaces are all up (hint: show ip interface brief) 13. Enter config mode and type config-register 0x2102, this will reset the config register to boot from your saved configuration file (with all your new passwords) Router#configure terminal Router(config)#config-register 0x02102 14. Press Ctrl-z or end to leave the configuration mode. The prompt is now hostname#. 15. Type copy running-config startup-config to save the changes. Your done! Restart the router and login Rapture Email : rapture_uidzero@hotmail.com CMS : rapture

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Comments: zethyr 2004-12-23 16:55:14 Good work :) I'm looking forwards to testing this on some kind of cisco-router I may find. Detailed and good work, so anybody can do it without much basic knowledge. Anonymous 2008-10-15 17:11:15 I agree with TroPe ... this author has taken the time to write out a most frequently used procedure (especially if you are teaching CCNA and such) Anonymous 2008-11-07 15:05:09 Thanks, this worked. Chris NYC Anonymous 2008-12-03 14:02:35 Thanks alot :) Works every time! ;p Anonymous 2008-12-08 04:21:02 This is great information. Just got my 2600 and this solved my password issue. Bought used and now I can begin my training! Thanks, Ryan Anonymous 2008-12-16 00:51:53 Excellent! Thanks for the heads-up! Anonymous 2009-01-04 18:41:15 Thanks m8. It does work!!! Anonymous 2009-02-26 19:17:52 Thanks a lot man! Worked great for me on three different Cisco router models! Anonymous 2009-05-21 17:11:32 awesome... Just add how to nuke the config after you wipe the enable secret. Anonymous 2010-02-11 10:57:43 how to reset my cisco password if i forgot from remote location cisco 1800 series Anonymous 2010-03-09 18:58:47 Work like a charm on a Cisco 2600 Series - Thanks Rapture! Anonymous 2010-12-10 09:27:43 Thanks a lot and God Bless u Anonymously add a comment: (or register here) (registration is really fast and we send you no spam) BB Code is enabled. Captcha Number: