Sybex CCNA Chapter 4: Cisco’s IOS and SDM Instructor & Todd Lammle

Chapter 4 Objectives The Cisco router IOS Enhanced editing Administrative functions –Hostnames –Banners –Passwords –Interface descriptions Verifying your configuration 2

Cisco Router IOS Carries network protocols and functions Connects high-speed traffic between devices Adds security to control access Provides scalability for growth Supplies reliability

Connecting To A Cisco Router Cisco 2811 Cisco 1841

Bringing up a Router –There are four major phases to the bootup process: –1. Performing the POST –2. Loading the bootstrap program –3. Locating and loading the Cisco IOS software –4. Locating and loading the startup configuration file or entering setup mode

Bringing up a Router 1. Performing the POST Power-On Self Test (POST) When the router is powered on, software on the ROM chip conducts the POST. During this self-test, the router executes diagnostics from ROM on several hardware components including the CPU, RAM, and NVRAM. After the POST has been completed, the router executes the bootstrap program.

Bringing up a Router 2. Loading the Bootstrap Program After the POST, the bootstrap program is copied from ROM into RAM. Once in RAM, the CPU executes the instructions in the bootstrap program. The main task of the bootstrap program is to locate the Cisco IOS and load it into RAM.

Bringing up a Router 3. Locating and Loading Cisco IOS The IOS is typically stored in flash memory. Note: Once the IOS begins to load, you may see a string of pounds signs (#) while the image decompresses. ############################

Bringing up a Router 4. Locating and Loading the Configuration File Bootstrap program searches for the startup configuration file, known as startup-config, in NVRAM. file is copied into RAM as the running configuration file, running-config. If the startup configuration file can not be located, then we enter setup mode.

Memory ROM : bootstrap Flash Memory : Cisco IOS NVRAM : permanent storage for the startup configuration file (startup-config) If we made changes then we must save it to the NVRAM

Remember every interface on the router is a member or host on a different IP network. Each interface must be configured with an IP address and subnet mask of a different network.

Command-Line Interface (CLI) More flexible than setup mode. To use the CLI, just say No to entering the initial configuration dialog.

Modes User mode: –Router> –Used mostly to view statistics Privileged mode: –enable –Router# –Used to view & change router configuration Global configuration mode. config terminal or config t –Router (config)#

Configuration certain basic tasks are performed including: Naming the router Setting passwords Configuring interfaces Configuring a banner Saving changes on a router Verifying basic configuration and router operations

Configuration Naming the router Setting passwords Privileged mode Console, Telnet

Configuration Banner Saving changes

Configuration Interface configuration Try network address, incorrect mask ?

Showing the work Lets try it out !