CCNAv3.3 205

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CCNA Semester 2

Chapter 05Chap

ter 05

MANAGING CISCOMANAGING CISCOIOS SOFTWAREIOS SOFTWARE

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ObjectivesObjectives

• Identify the stages of the router bootsequence

• Determine how a Cisco device locates andloads the Cisco IOS

• Use the boot system command

• Identify the configuration register values

• Briefly describe the parts of the IOS name

• Save and restore configuration files using TFTPand copy-and-paste

• Load an IOS image using TFTP

• Load an IOS image using XModem

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3

Table of ContentTable of Content

1 Router boot sequence and verification

2 Managing the Cisco file system

3 Password recovery

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ROUTER BOOT SEQUENCE ANDROUTER BOOT SEQUENCE AND

VERIFICATIONVERIFICATION

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Router Startup SequenceRouter Startup Sequence

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Router Startup FlowchartRouter Startup Flowchart

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How A Cisco Device Locates And Loads IOSHow A Cisco Device Locates And Loads IOS

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Using The Boot System CommandUsing The Boot System Command

Router(config)#boot system flash gsnew-image

Router(config)#boot system tftp gsn-image

1.1.1.1Router(config)# boot system rom

Remember

• copy running-config startup-config

• The router will execute the boot systemcommands in the order in which they were

originally entered into configuration mode.

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Config-registerConfig-register

0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 10x0x2101 : Boot system from ROM

0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 00x0x2102 : Boot system from flash

0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 00x

0x2100 : System bootstrap prompt

Configuration register bits 3, 2, 1, and 0 set bootoption

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Configuration RegisterConfiguration Register

Configuration RegisterValue

Description

0xnnn0 Use Rom Monitor mode

0xnnn1 Automatically boot fromROM

0xnnn2 – 0xnnnF Examine NVRAM for bootsystem commands

Router# Show versionRouter(config)#configure-register register-value

Ex: Router(config)#configure-register 0x2142

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Determining Configuration Register ValueDetermining Configuration Register Value

wg_ro_a#show versionCisco Internetwork Operating System SoftwareIOS (tm) 2500 Software (C2500-JS-L), Version 12.0(3), RELEASE SOFTWARE (fc1)Copyright (c) 1986-1999 by cisco Systems, Inc.Compiled Mon 08-Feb-99 18:18 by phanguyeImage text-base: 0x03050C84, data-base: 0x00001000

ROM: System Bootstrap, Version 11.0(10c), SOFTWAREBOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version 11.0(10c), RELEASE SOFTWARE (fc1)

wg_ro_a uptime is 20 minutesSystem restarted by reload System image file is "flash:c2500-js-l_120-3.bin"

--More--

Configuration register is 0x2102

• Configuration register value in show version

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MANAGING THE CISCO FILE SYSTEM

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IOS File System OverviewIOS File System Overview

Prefix DescriptionFlash: Flash memory; Platforms that donot have a device named flash isaliases to slot0

Flh: Flash load helper log files

ftp: File transfer protocol

Nvram: NVRAM

Rcp: Remote copy protocol networkserver

Tftp: Tftp network server

System: Contains the system memory

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IOS Naming ConventionsIOS Naming Conventions

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Managing configuration files using TFTPManaging configuration files using TFTP

Router# copy running-config tftpAddress or name of remote host[]? 10.10.10.10Destination filename [Router-config]?!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!624 bytes copied in 7.05 secs

Router#

Router# copy tftp running-configAddress or name of remote host[]? 10.10.10.10Source filename[] ?router-config

Destination filename [running-config]?Accessing tftp://10.10.10.10/router-configLoading router-config from 10.10.10.10 (via ethernet 0/0)!!!!!!!!!!!!!!!!!!!!!!!!![OK-642 bytes]

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Managing Configuration Files Using Copy (Hyper Terminal)Managing Configuration Files Using Copy (Hyper Terminal)

• Select Transfer • Select Capture Text

• Specify the name for the text file to capture theconfiguration. Select Start to start capturing text

• Display the configuration to the screen by entering showrunning-config

• Press the space bar when each "-More -" prompt appears

• When the complete configuration has been displayed,

stop the capture by:• Select Transfer

• Select Capture Text

• Select Stop

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Managing Configuration Files Using CopyManaging Configuration Files Using Copy

• Edit the configuration file: delete the linesfollowing:

– Show running-config– Building configuration…

– Current configuration …

– - More –

– Any lines that appear after the word End

– Add the no shutdown command to the end of each interface section

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Managing Configuration Files Using CopyManaging Configuration Files Using Copy

• Enter router global configuration mode.• Click on Transfer > Send Text File in

HyperTerminal.

• Select the name of the file for the saved

backup configuration.• Watch as the lines of the file are entered into

the router.

• Observe any errors.

• Press Ctrl-Z to exit global configuration modeafter the configuration is entered.

• Restore the startup configuration with thecopy running-config startup-config command.

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Managing IOS images using XmodemManaging IOS images using Xmodem

• Why the IOS image did not load fromflash

– The flash should be examined with the dir

flash

rommon 1>boot flash:c2600-is-mz.121-5

– Or show version

– Or show startup-config • A user can restore the image from the

ROMmon mode (rommon 1> prompt ).

– Xmodem through the console

– Or use TFTP to download the image

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• In HyperTerminal

– select Transfer > Send File.

– In the Send File popup specify the image nameand location, select Xmodem as the protocol, andstart the transfer

• Before the router is restarted

– set the console speed back to 9600

– and the config register back to 0x2102. Enter thecommand config-register 0x2102

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Environment variablesEnvironment variables

• The fastest way to restore an IOS image to the routeris to use TFTP from ROMmon to download the image

• rommon 10 >set

• rommon 10 > IP_ADDRESS=10.10.10.10• rommon 11 > IP_SUBNET_MASK=255.255.255.0

• rommon 12 > DEFAULT_GATEWAY=10.10.10.10

• rommon 13 > TFTP_SERVER=10.10.10.11• rommon 14 > TFTP_FILE=C2600-IS-MZ.120-7.T.BIN

• rommon 15 >

• rommon 15 > tftpdnld

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File System Verification: show flash, showFile System Verification: show flash, show

versionversion• Cisco Internetwork Operating System Software

• IOS (tm) 2500 Software (C2500-D-L), Version 12.0(10), RELEASE SOFTWARE (fc1)

• Copyright (c) 1986-2000 by cisco Systems, Inc.

• Compiled Mon 20-Mar-00 22:33 by phanguye

• Image text-base: 0x0303882C, data-base: 0x00001000

• ROM: System Bootstrap, Version 11.0(10c), SOFTWARE

• BOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version 11.0(10c), RELEASESOFTWARE (fc1)

• SGCTT-HCM uptime is 1 week, 1 day, 1 hour, 9 minutes

• System restarted by power-on

• System image file is "flash:c2500-d-l.120-10"

• cisco 2500 (68030) processor (revision N) with 2048K/2048K bytes of memory.

• Processor board ID 23101339, with hardware revision 00000000

• Bridging software.• X.25 software, Version 3.0.0.

• 1 Ethernet/IEEE 802.3 interface(s)

• 2 Serial network interface(s)

• 32K bytes of non-volatile configuration memory.

• 8192K bytes of processor board System flash (Read ONLY)

• Configuration register is 0x2102

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File System Verification: show flash, showFile System Verification: show flash, show

versionversion

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PASSWORD RECOVERYPASSWORD RECOVERY

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Config-registerConfig-register

• 0 – 3: Boot field

• 6: Ignore NVRAM contents• 8: Break disabled

• 11-12: Console line speed

• 13: Boot ROM if network fails• 15: Diagnostic and ignore NVRAM

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Password RecoveryPassword Recovery

1. Cold boot the router

2. Press CTRL-BREAK within 60 seconds3. Change configuration register:

C2500: o/r 0x2142

C2600: confreg 0x2142

4. Initial the router: i or reset

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Password Recovery (cont.)Password Recovery (cont.)

5. Do not use setup mode

6. Access to privileged mode

7. copy startup-config running-config

8. change enable password

9. change configuration register to 0x2102

10.copy running-config startup-config

11.reload

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SummarySummary

• Identifying stages of the router boot sequence

• Identifying how the Cisco device locates and loads the Cisco IOS

• Using the boot system command

• Identifying the configuration register settings

• Troubleshooting problems• Identifying the files used by the Cisco IOS and their functions

• Identifying the locations on the router of the different file types

• Identifying the parts of the IOS name

• Managing configuration files using TFTP• Managing configuration files using copy-and-paste

• Managing IOS images with TFTP

• Managing IOS images with XModem

• Verifying the file system using show commands

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Q&AQ&A

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Preparation for LABPreparation for LAB

• LAB: Router password recovery.

Documents

CCNAv3.3 205