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Module 5: Managing Cisco IOS Software

Frank Mann CCAI-CCNA

Router Internal Components

Routers have different types of memory

Routers need to locate the Config file and the IOS

5.1 Router Boot Sequence and Verification

Startup routines must do the following:• Test the router hardware.

• Find and load the Cisco IOS software.

• Find and apply configuration statements, including protocol functions and interface addresses.

Router Power-On/Bootup Sequence

1. Perform power-on self test (POST).

2. Load and run bootstrap code.

3. Find the Cisco IOS software.

4. Load the Cisco IOS software.

5. Find the configuration.

6. Load the configuration.

7. Run the configured Cisco IOS software.

5.1.2 How a Cisco device locates and loads IOS

Finding the Cisco IOS Software

Router Startup Flowchart

Loading the Configuration

• Load and execute the configuration from NVRAM.

• If no configuration is present in NVRAM, enter setup mode.

Determining the Current Configuration Register Value

wg_ro_a#show versionCisco Internetwork Operating System Software IOS (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 reloadSystem image file is "flash:c2500-js-l_120-3.bin"

--More--

Configuration register is 0x2102

• Configuration register value in show version

• Configuration register bits 3, 2, 1, and 0 set boot option.

• Check the configuration register value with show version.

Configuration Register Values

Configuration Register Values

show version CommandRouter#show versionCisco Internetwork Operating System SoftwareIOS (tm) C2600 Software (C2600-JS-M), Version 12.0(7a), RELEASE SOFTWARE (fc1)Copyright (c) 1986-2002 by cisco Systems, Inc.Compiled Tue 05-Feb-02 01:48 by pwadeImage text-base: 0x80008088, data-base: 0x80B0404C

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 1 minuteSystem restarted by reloadSystem image file is "flash:c2600-js-mz.120-7a.bin"

cisco 2610 (MPC860) processor (revision 0x300) with 53248K/12288K bytes of memory.Processor board ID JAD06090BMD (2719249260)M860 processor: part number 0, mask 49Bridging software.X.25 software, Version 3.0.0.SuperLAT software (copyright 1990 by Meridian Technology Corp).TN3270 Emulation software.Basic Rate ISDN software, Version 1.1.1 Ethernet/IEEE 802.3 interface(s)2 Serial(sync/async) network interface(s)1 ISDN Basic Rate interface(s)32K bytes of non-volatile configuration memory.16384K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

show flash Command

wg_ro_a#show flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin [10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

wg_ro_a#show flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin [10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

show running-config and show startup-config Commands

wg_ro_c#show startup-configUsing 1359 out of 32762 bytes!version 12.0!

-- More --

wg_ro_c#show running-configBuilding configuration...

Current configuration:!version 12.0!

-- More --

In NVRAMIn RAM

• Displays the current and saved configuration

Loading the Cisco IOS Software from Flash Memory

•The flash memory file is decompressed into RAM.

Loading the Configuration

• Load and execute the configuration from NVRAM.

• If no configuration is present in NVRAM, enter setup mode.

5.1.5 Troubleshooting IOS boot failure

In the event that the router does not boot properly, there are several things that could be wrong:• Configuration file has missing or incorrect

boot system statement

• Incorrect configuration register value

• Corrupted flash image

• Hardware failure

© 2002, Cisco Systems, Inc. All rights reserved. 19

Managing Cisco IOS Devices

Cisco IOS File System and Devices

Managing Cisco IOS Images

wg_ro_a#show flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin

[10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

• Verify that flash memory has room for the Cisco IOS image.

Verifying Memory and Deciphering Image Filenames

Verifying Memory and Deciphering Image Filenames

5.2 Prefixes for Managing the Cisco File System

• Back up current files prior to updating flash memory.

Creating a Software Image Backup

Upgrading the Image from the Network

Device Configuration Files

5.2.4 Managing configuration files using copy and paste

Cisco IOS copy Command

• NVRAM

• Terminal

• TFTP server

• Erase start

Cisco IOS copy Command from TFTP

An IOS image can be copied into flash from a TFTP server • A series of "e's" are displayed as the current IOS

image is erased from flash.

• A series of "!'s" are displayed as the image is downloaded successfully to flash

• After the new flash image is downloaded, it is verified

Cisco IOS copy Command Example

interface s0 ip address 10.1.1.1 255.255.255.0

interface e0 ip address 10.2.2.2 255.255.255.0

interface e1 no ip address

interface s0 ip address 10.1.1.1 255.255.255.0

interface e0 ip address 10.2.2.2 255.255.255.0

interface e1 no ip address

interface e0 ip address 172.16.1.1 255.255.255.0

interface e1 ip address 192.168.1.1 255.255.255.0

interface e0 ip address 172.16.1.1 255.255.255.0

interface e1 ip address 192.168.1.1 255.255.255.0

interface s0 ip address 10.1.1.1 255.255.255.0

interface e0 ip address 172.16.1.1 255.255.255.0

interface e1 ip address 192.168.1.1 255.255.255.0

interface s0 ip address 10.1.1.1 255.255.255.0

interface e0 ip address 172.16.1.1 255.255.255.0

interface e1 ip address 192.168.1.1 255.255.255.0

running-config TFTP Server saved.cfg

Resultingrunning-config

copy tftp run (merged)

copy run tftp and copy tftp run Commands

wg_ro_a#copy running-config tftp Address or name of remote host []? 10.1.1.1 Destination filename [running-config]? wgroa.cfg .!!1684 bytes copied in 13.300 secs (129 bytes/sec) wg_ro_a#copy tftp running-config Address or name of remote host []? 10.1.1.1 Source filename []? wgroa.cfg Destination filename [running-config]? Accessing tftp://10.1.1.1/wgroa.cfg... Loading wgroa.cfg from 10.1.1.1 (via Ethernet0): ![OK - 1684/3072 bytes]

1684 bytes copied in 17.692 secs (99 bytes/sec)

wg_ro_a#copy running-config tftp Address or name of remote host []? 10.1.1.1 Destination filename [running-config]? wgroa.cfg .!!1684 bytes copied in 13.300 secs (129 bytes/sec) wg_ro_a#copy tftp running-config Address or name of remote host []? 10.1.1.1 Source filename []? wgroa.cfg Destination filename [running-config]? Accessing tftp://10.1.1.1/wgroa.cfg... Loading wgroa.cfg from 10.1.1.1 (via Ethernet0): ![OK - 1684/3072 bytes]

1684 bytes copied in 17.692 secs (99 bytes/sec)

Adding New Devices to the Network

1. Determine the IP address to be used for management purposes.

2. Configure administrative access for the console, auxiliary, and vty interfaces.

3. Configure passwords for the privileged EXEC mode for the device.

4. Configure the network management access to the device.

5. Determine the IP address to assign to each interface.

6. Configure the new device with the appropriate configuration.

Moving Devices on the Network

• Determine what to do with the obsolete equipment.

–Which devices connect to the equipment being moved?

–Will the move and reconfiguration affect the security policy?

–Does the device play a role that no other devices play?

• Review the facilities for the new location.

• After the move, test network connectivity.

Changing the Hardware

Hardware changes• Power down the equipment or use OIR.

• Make sure the appropriate modules are available.

• Read the hardware installation manual.

• Verify your organization’s policies.

Cisco IOS software changes• Does the new version support the current and future

features you need?

• Does your platform have sufficient RAM and flash memory to support the feature set?

show and debug Commands

Processing characteristic

Processing load

Primary use

show

Static

Low overhead

Gather facts

debug

Dynamic

High overhead

Observe processes

Considerations When Using debug Commands

• May generate output in a variety of formats that may not identify the problem

• Require high overhead, possibly disrupting network device operation

• Useful for obtaining information about network traffic and router status

Commands Related to debug

Router(config)#service timestamps debug datetime msec

Router#show processes CPU utilization for five seconds: 0%/0%; one minute: 0%; five minutes: 0% PID Q Ty PC Runtime(ms) Invoked uSecs Stacks TTY Process 1 C sp 602F3AF0 0 1627 0 2600/3000 0 Load Meter 2 L we 60C5BE00 4 136 29 5572/6000 0 CEF Scanner 3 L st 602D90F8 1676 837 2002 5740/6000 0 Check heaps 4 C we 602D08F8 0 1 0 5568/6000 0 Chunk

Manager 5 C we 602DF0E8 0 1 0 5592/6000 0 Pool Manager 6 M st 60251E38 0 2 0 5560/6000 0 Timers

Router#no debug all

Summary

• The Cisco IOS File System feature provides a single interface to all the file systems that a router uses.

• As your network grows, you may want to store your Cisco IOS software and configuration files on a central server, which would allow you to control the number and revision level of software images and configuration files you must maintain.

• Device configuration files contain a set of user-configured commands that customize the functionality of your Cisco device.

Summary (Cont.)

• You use the Cisco IOS software copy commands to move configurations from one component or device to another, such as RAM, NVRAM, or a file server.

• Network equipment is often moved from one location to another, removed from the network, or the configuration may change. The process is referred to as adds, moves, and changes.

• The show and debug commands are built-in tools for troubleshooting. The show command is used to display static information, while the debug command is used to display dynamic data.

Module 5: Managing Cisco IOS Software

Lab:

5.1.3 Using the Boot System Command

5.1.5 Troubleshooting Config Register Boot Problems

5.2.3 Managing Configuration Files with TFTP

5.2.5 Managing IOS Images with TFTP

5.2.6a Password Recovery Procedures

5.2.6b Managing IOS Images with ROMmon and Xmodem

e-Lab:

5.1.3 Preparing for Boot System Commands

5.1.4 Configuration Register

5.1.5 Troubleshooting IOS Boot Failure