Sunday, January 21, 2018

IAM Search

Routers and Routing Basics - Introduction to Routers

Internetwork Operating System

• Like any computer, networking devices need an operating system to function.

– Workstations use UNIX, Windows, Mac OS.

– Cisco routers and switches use Cisco IOS.

• IOS core generally uniform across most routers and Catalyst switches.

• Cisco IOS utilises a command line interface (CLI), accessed by:

– Console session via a local serial connection.

– Auxiliary session via remote dial-up connection.

– Virtual terminal session via remote IP connection.

How to use Cisco IOS

• Device modes of operation:

• Cisco IOS modes of operation:

Image is Everything

• All Cisco IOS images utilise a common core of basic configuration command structure across all supported Cisco devices.

• Different IOS images developed for different hardware platforms, each with a different software feature set.

– More features in the image requires more RAM and Flash memory in the destination device.

– Important to check the Cisco device meets the requirements of the IOS to be installed.

• Display RAM and Flash memory capacities using show version in Privileged EXEC

• Show Flash usage using show flashin Privileged EXEC

The power of IOS. Now.

• For a router to be operational, it must:

– Test the hardware for errors

• Done by Power On Self Test (POST) in ROM.

– Locate and load the Cisco IOS

• Bootstrap loads from ROM, then locates IOS image from Flashand copies it into RAM.

• As IOS loads, router hardware information is displayed, including router model, processor, amount of memory, and number and types of interfaces.

– Locate and apply the router config file

• IOS looks for config file in NVRAM.

• If there’s no config file to apply, then IOS initiates setup dialogue.

IOS QuickStart Guide

• Access to the CLI is provided at two levels:

– User EXEC: Limited router monitoring

– Privileged EXEC: Unrestricted access to all router commands

• Access restricted by use of enable secret command.

– Global configuration mode: Apply configuration changes to a router.

• Access only via Privileged EXEC mode.

• A list of available commandscan be displayed by entering ? at the CLI prompt.

• If a command is incorrectly entered at the CLI prompt, a message highlighting the error will appear.

– % Invalid input detected at '^' marker

Take Command of IOS

Comments (0)Add Comment

Write comment

security code
Write the displayed characters



  • ...more


Important: All images are copyrighted to their respective owners. All content cited is derived from their respective sources.

Contact us for information and your inquiries. IAMechatronics is open to link exchanges.

IAMechatronics Login