chap 7 ios images

Chap 7IOS Images

Andres, Wen-Yuan Liao

Department of Computer Science and Engineering

De Lin Institute of Technology

andres@dlit.edu.tw

http://www.cse.dlit.edu.tw/~andres

Overview

Cisco IOS software source optionsLoad IOS software onto the routerMaintain backup filesUpgrade IOS software

The functions of the conf. register

The Basics of IOS Versions

Locating the Cisco IOS software

Configuration register values

The show version command

Locating the Cisco IOS software

The default source depends on the hardware platform

The router looks to the boot system commands saved in NVRAM

NVRAMConfiguration register: Boot fieldROM moniter / ROM / Boot system

commandRouter#config-register

Boot system commandFlash/TFTP/ROMRouter(config)#boot system

Boot system

Global configuration-mode boot system commands to enter fallback sources for the router to use in sequence

Configuration register values

Configuration register:boot fieldDetermine the order in which the rout

er looks for system bootstrap information

Router#config-registerChange the default configuration regi

ster setting

The configuration register is a 16-bit register in NVRAM

The lowest 4 bits bits 3,2,1,0: the boot field

show version: verify the config-register command

Configuration register values

(default)

The show version command

Displays information about the Cisco IOS software version (system image)

The configuration register and the boot field setting

Bootstrap Options in Software

Boot system commands

Preparing for the use of TFTP

The show flash command

Preparing for the use of TFTP

A TFTP server will allow image and conf. uploads and downloads over the networkAnother router or host system

The show flash command

Verify that you have sufficient memory on your system for the Cisco IOS software

Always backup your current IOS before upgrading to a newer version

IOS Naming and Software Image Backup

Cisco's IOS naming conventions

The copy flash tftp command

The copy tftp flash command

How to load a software image backup

Cisco's IOS naming conventions

These images accommodate the various platforms, available memory resources, and feature set needs customers have for their network devices

The copy flash tftp command show flash command to learn the name of the system image file (xk09140z)copy flash tftp command to copy the system image to a TFTP server

The copy tftp flash command

copy tftp flashDownload the new image from the TFTP server

Flash memory for more than a single Cisco IOS image

Exclamation point (!) : successfully transferredVs: successful checksum verification

Summary

Configuration commands in NVRAM

The show version command

IOS: Flash/TFTP server/ROM

show flash

Naming convention

copy flash tftp/copy tftp flash