Understanding Cisco IOS

Cisco IOS

As you know that Cisco is the worldwide leader in providing the hardware solutions as well as the software solutions of LAN and WAN. The hardware solutions mean that the hardware devices such as switches and routers etc but what is the meaning of software solution? The software solution actually means that Cisco manufactures manageable devices with a CLI based Cisco IOS Software installed in these devices. With the help of this software you can better manage your network and internetwork environment.

Once you have performed and inspection on the physical components of the Cisco switches and the routers, locate and record the IOS version being used by the router or switch with the show version command. In the display of show version command, the second line lists the following IOS running on a router or switch like:


4500 Software (C 4500-JS-M), version 11.2 (11)

This is reconfirmed in the middle of the show version display with the following line:

System image file is "flash: c4500-js-mz_112-11.bin", booted via flash

This line list the file name as it appears in the flash memory of router.

Knowing how to determine what release and what type of IOS is running on a switch or router is important and critical for proper router administration and configuration. Different IOS images possess different capabilities and features for example, if the IOS is pre-11.2 release, you can not configure integrated routing and bridging or NAT on that router or there is no support of named access lists on that router. Selecting the correct set of IOS feature and the exact version is essential to maintain optimal router and switch performance.

Cisco IOS Download


To download Cisco IOS for a given router or switch, three key elements to be aware of are as follows:

If you have the proper Cisco maintenance agreement then you have the privileges to download multiple IOS images directly from the official website of Cisco. Cisco has an"IOS planner" that guides you through the selection process of Cisco IOS under Software Centre on the Cisco website.

If you use the Cisco IOS planner, the first parameter to be selected is the platform of router or switch. Once a platform has been selected, then a major release must be selected. The recent router IOS releases are:

If you want the latest IOS releases then select Cisco IOS 12.4 download from the Cisco website.

Cisco IOS Commands

Here are the some basic Cisco IOS commands including in the Cisco IOS command line reference book and are used for configuring and verifying the configuration of the Cisco routers and switches:



Top 5 Free Networking Tools

Bookmark Understanding Cisco IOS

Latest Blog Posts


English English GermanGerman SpanishSpanish FrenchFrench ItalianItalian PortuguesePortuguese RussianRussian DutchDutch
GreekGreek HindiHindi JapaneseJapanese KoreanKorean ChineseChinese Chinese (Simplified)Chinese (Simplified) ArabicArabic

Copyright 2009 Tech-FAQ. All rights reserved. Privacy Policy.