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What would be the purpose of setting the router configuration register to 0x2102?
Wiki User
∙ 11y ago
you can use 2100 when you have a corrupt nvram and your router refuses to boot up
Wiki User
∙ 12y ago
Wiki User
∙ 11y agoLoad NVRAM
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What is the default configuration register setting for a cisco router?
0x2102
How do you break password of CISCO router?
Step-by-Step ProcedureFollow these steps in order to recover your password:Attach a terminal or PC with terminal emulation to the console port of the router.Use these terminal settings:9600 baud rateNo parity8 data bits1 stop bitNo flow controlRefer to these documents for information on how to cable and connect a terminal to the console port or the AUX port:Cabling Guide for Console and AUX PortsConnecting a Terminal to the Console Port on Catalyst SwitchesConnect a Terminal to Catalyst 2948G-L3, 4908G-L3, and 4840G Series SwitchesIf you can access the router, type show version at the prompt, and record the configuration register setting. See Example of Password Recovery Procedure in order to view the output of a show version commandNote: The configuration register is usually set to 0x2102 or 0x102. If you can no longer access the router (because of a lost login or TACACS password), you can safely assume that your configuration register is set to 0x2102.Use the power switch in order to turn off the router, and then turn the router back on.Important Notes:In order to simulate this step on a Cisco 6400, pull out and then plug in the Node Route Processor (NRP) or Node Switch Processor (NSP) card.In order to simulate this step on a Cisco 6x00 with NI-2, pull out and then plug in the NI-2 card.Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON.If the break sequence does not work, refer to Standard Break Key Sequence Combinations During Password Recovery for other key combinations.Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.This step bypasses the startup configuration where the passwords are stored.Type reset at the rommon 2> prompt.The router reboots, but ignores the saved configuration.Type no after each setup question, or press Ctrl-Cin order to skip the initial setup procedure.Type enable at the Router> prompt.You are in enable mode and should see the Router# prompt.Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.Important: Do not type copy running-config startup-config or write. These commands erase your startup configuration.Type show running-config.The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces are currently shut down. In addition, the passwords (enable password, enable secret, vty, console passwords) are in either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change encrypted passwords to a new password.Type configure terminal.The hostname(config)# prompt appears.Type enable secret in order to change the enable secret password. For example:hostname(config)#enable secret ciscoIssue the no shutdown command on every interface that you use.If you issue a show ip interface brief command, every interface that you want to use should display up up.Type config-register . Where configuration_register_setting is either the value you recorded in step 2 or 0x2102 . For example:hostname(config)#config-register 0x2102Press Ctrl-z or end in order to leave the configuration mode.The hostname# prompt appears.Type write memory or copy running-config startup-config in order to commit the changes.
What cisco ios command would you use to find out the value of the config register on a cisco router?
As most things on IOS, show is the way to go.When you do show version, the last line will tell you the current value of the configuration register. Sample output below.Router#show versionCisco Internetwork Operating System SoftwareIOS (tm) 2500 Software (C2500-JS-L), Version 12.1(5), RELEASE SOFTWARE (fc1)Copyright (c) 1986-2000 by cisco Systems, Inc.Compiled Wed 25-Oct-00 05:18 by cmongImage text-base: 0x03071DB0, data-base: 0x00001000ROM: System Bootstrap, Version 5.2(8a), RELEASE SOFTWAREBOOTFLASH: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fc1)Router uptime is 7 minutesSystem returned to ROM by reloadSystem image file is "flash:c2500-js-l_121-5.bin"cisco 2500 (68030) processor (revision D) with 16384K/2048K bytes of memory.Processor board ID 03867477, with hardware revision 00000000Bridging software.X.25 software, Version 3.0.0.SuperLAT software (copyright 1990 by Meridian Technology Corp).TN3270 Emulation software.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
How do you recover the password for a Cisco 2600 router?
First, get yourself a serial cable and access to the console port. When you have that arranged, try to get (unprivileged will do) access to the router's prompt and run a show versioncommand. Record the value of the configuration register. If you can't login, you can assume it's 0x2102.Next, powercycle the router. Within 60 seconds of power on, send a BREAK key down the serial console to put the router into ROMMON mode, which stops it booting IOS.At the prompt rommon 1> type confreg 0x2142 to instruct the router to boot from flash, but not load the startup-config. Type reset next.After the router is restarted it'll ask to go into setup mode, don't do that.Type enable or en.Type copy start run.Type show run . You will see some passwords unencrypted, which you can simply write down. The enable secret, if used, will be encrypted and must be reset.Type conf t .Type enable secret to reset the enable secret to your new password.Issue a no shut for each interface you use.Type config-register 0x2102 (or the value you wrote down earlier)Type end .Type copy run start to save your changes.
