Chapter 7.
Working with Router
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CHAPTER OBJECTIVES
At the end of this Chapter you will be able to:
Identify Console Ports, AUX Port, Hardware Interfaces
Perform Basic configuration of a router
Understand IOS Concepts
Understand router configuration files
Use the CLI to Setup a Basic Router Configuration
Manage CISCO IOS
Manage IOS configuration files
Use basic IOS commands and various modes of router
Understand booting process of a router
Perform basic network configuration and host name
resolution
Identify, prescribe, and select the appropriate media, cables,
ports, and connectors to connect routers to other network
devices and hosts
Connect, configure, and verify operation status of a device
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interface
Rear Panel of the Cisco
Router
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Router Ports

Router ports help to configure the router, verify its configuration and
access Cisco IOS
Router Ports
Console Port
Auxiliary Port
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Router Ports
Console Cable
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Auxiliary Port on a Cisco Router
The purpose of the auxiliary port is for connecting to an external
modem. Once configured, this modem can be used as a backup
demand-dial connection to another location, or as a way to dial in
to the router for troubleshooting purposes
An Auxiliary Port
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Router Components

Router components allow the router to enter the boot up process, load its
operating system, and configuration files
Router
Components
Processor
ROM
RAM
Flash
NVRAM
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Configuration
Register
Router Boot Sequence
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Router Modes
Password
New Chapter
USER
Password
Enable
Privileged
Config terminal
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1. User mode
 User can examine router status and operation.
 Configuration cannot be viewed or altered from user mode
Prompt : router>
2.Privileged mode (“root”)
 Complete control over the router (anything can be set or reset)
 Configuration cannot be altered
Prompt : router#
3.Configuration mode
Used only for change of configuration.
Not password protected from privileged mode.
Privileged mode commands don’t have meaning in configuration
mode.
Most statements can be removed from the configuration with the
prefix
no (ex. no shutdown)
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Prompt : router(config)#
Summary of Router Modes
Mode Name
Description
Router>
User Mode
Router#
Privileged Mode
Router(config)#
Global configuration mode
Router(config-if)#
Interface mode
Router(config-subif)#
Subinterface mode
Router(config-line)#
Line mode
Router(config-router)#
Router configuration mode
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Accessing Help and History
Command
Description
?
Help for all available commands in the mode
Command ?
Describes all the first parameters of the command
com?
Lists the commands that begin with com
command parm?
Lists the characters that begin with parm
command parm<Tab>
When the tab is pressed in between the word, the CLI completes the
word. If the CLI is idle, it indicates that the typed characters can form
more possible words
command parm1 ?
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Lists all the next parameters and their description
Enhanced Editing Commands - I
The enhanced editing commands include:
 Ctrl + A - Moves the cursor to the beginning of a line
 Ctrl+E - Moves the cursor to the end of the line
 Esc+B - Move the cursor back by one word
 Ctrl+B - Move the cursor back by one character
 Ctrl+F - Move the cursor forward by one character
 Esc+F - Move the cursor forward by one word
 Ctrl+D - Deletes one character
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Enhanced Editing Commands - II
 Backspace - Deletes one character
 Ctrl+R - Recalls a line
 Ctrl+U - Deletes a line
 Ctrl+W - Deletes a word
 Ctrl+Z - Returns to EXEC from the configuration
mode
 Tab - Finishes typing a word
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Router History Commands
Command
Description
Ctrl+P or Up arrow
Displays the last command entered
Ctrl+N or Down arrow Displays the previously entered commands
show history
Displays the last 10 command entered
show terminal
Displays terminal configuration and size of
history buffer
terminal history size
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Allows to change the buffer size
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Router Administrative Functions
 Router administrative functions allow easy troubleshooting and
maintenance of routers
 Router administrative function include:
 Assigning hostname
 Assigning banners
 setting password
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Banners
 Banner is a message displayed to all the users when they access
the router through Telnet, console and auxiliary ports
 It can be used to display information about the router itself or
nay kind of security message
 Four types of banners available for the Cisco routers are:
 Message of the day banner
 Exec process creation banner
 Incoming terminal line banner
 Login banner
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Creating a Login Banner
“Login Banner” lets you set the message at the login prompt, you
can personalize the message as required time to time.
Command Name
Description
Router(config)#banner login #
Authorized Personnel Only! Please
enter your username and
password. #
# is known as a “delimiting character”.
The delimiting character must
surround the banner message and can
be any character so long as it is not a
character used within the body of the
message.
Router(config)#
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Creating a “Message-of-the-day” Banner
Message of the day (MOTD) is the most extensively used banner. It
gives a message to every person dialing into or connecting to the
router via Telnet or an auxiliary port, or even through a console
port as seen here:
Command Name
Description
Router(config)#banner motd #
Building Power will be interrupted
next Tuesday evening from 8-10 PM.
#
# is known as a “delimiting
character”. The delimiting character
must surround the banner message
and can be any character so long as
it is not a character used within the
body of the message.
Router(config)#
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Basic Router Commands
Command Name
Description
Router#?
Lists all commands available in the current
command mode
Lists all the possible choices that start with the
letter c
Router#c?
Clear block
Router#cl
clear clock
Router#clock
% Incomplete command
Router#clock ?
Set
Router#clock set 19:50:00 14 June
2008 ? Enterkey
Router#
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Lists all the possible choices that start with
letter cl
Tells you that more parameters need to be
entered
Shows all subcommands for this command (in
this case, Set which sets the time and date)
Pressing the “Enter Key” confirms the time and
date configured.
No error message/Incomplete command
message means the command was entered
successfully.
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Configuring Passwords
Command Name
Description
Router(config)#enable password cisco
Sets enable password
Router(config)#enable enable
class
Router(config)#line console 0
Enter console line mode
secret Sets enable secret password
Router(config-line)#password console
Router(config-line)#login
Sets console line mode password to
console
Enable password checking at login
Router(config)#line vty 0 4
Enters vty mode for all five vty lines
Router(config-line)#password telnet
Sets vty password to telnet
Router(config-line)#login
Enables password checking at login
Router(config)#line aux 0
Enters auxiliary line mode
Router(config-line)#password backdoor
Sets auxiliary password to backdoor
Route(config-line)#login
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Enables password checking
at login
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Password Encryption
Command Name
Description
Router(config)#service passwordencryption
Applies a weak encryption to
password
Router(config)#enable password
CISCO
Router(config)#line console 0
Sets password to CISCO
Router(config-line)#password Cisco
Continue setting passwords
as above
………….
Moves to console line mode
Router(config)#no service password- Turns off password
encryption
encryption
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Connect, Configure, and Verify the Operational Status
of a Device Interface
Introduction
Interface descriptions:
•Serial Interface
•Fast Ethernet Interface
Moving between Interfaces:
Command Name
Description
Router(config)#interface serial
0/0/0
Router(config-if)#exit
Moves to serial interface
configuration mode
Returns to global configuration
mode
Moves to Fast Enternet
interface configuration mode
Router(config)# interface
fastethernet 0/0
Router(config-if)#
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In Fast Ethernet 0/0
configuration mode
now
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Configuring a Serial Interface
Command Name
Description
Router(config)#inteface s0/0/0/0
Router(config-if)#description Link to
ISP
Moves to serial interface
0/0/0/
Optional descriptor of the
link is locally significant
Router(config-if)# ip address
192.168.0.1 255.255.255.0
Assigns address and subnet
masks to interface
Router(config-if)#clock rate 56000
Assigns a clock rate for the
interface
Turns interface on
Router(config-if)#no shutdown
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Configuring a Fast Ethernet
Command Name
Description
Router(config)#inteface 0/0
Moves to Fast Ethernet 0/0
interface configuration mode
Router(config-if)#description
ACCOUNTING LAN
Optional descriptor of the link is
locally significant
Router(config-if)#ip address
192.168.20.1 255.255.255.0
Assigns address and subnet
masks to interface
Router(config-if)#no shutdown
Turns interface on
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Viewing, Saving, and Erasing Configurations
Saving Configurations
Command Name
Description
Router#copy running-config startup- Saves the running configuration
config
to a local NVRAM
Router#copy running-config tftp
Saves the running configuration
remotely to a TFTP server
Erasing Configurations
Command Name
Description
Router#erase startup-config
Deletes the startup configuration
file from NVRAM
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Show Commands
Command Name
Router#show ?
Router#show version
Rotuer#show
Rotuer#show
Router#show
Router#show
flash
history
interface ?
interface serial 0/0/0
Router#show interface brief
Router#show controllers serial 0/0/0
Router#show clock
Router#show hosts
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Description
Lists all show commands available.
Displays information about the current
Cisco IOS Software
Displays information about flash memory
Lists all commands in the history buffer
Displays statistics for all interfaces.
Displays statistics for a specific for a
specific interface (in this case, serial
0/0/0/)
Displays a summary of al interface,
including status and IP address assigned.
Displays statistics for interface hardware.
Statistics display if the clock rate is set
and if the cable is DCE, DTE, or not
attached.
Displays time set on device.
Displays local host-to-IP address cache.
These are the names and addresses of
hosts on the network to which you can
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connect.
Conti..
Router#show users
Router#show arp
Router#show protocols
Router#show startup-config
Router#show running-config
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Displays all users connected to device.
Displays the Address Resolution
Protocol(ARP) table.
Displays status of configured Layer 3
protocols.
Displays the configuration saved in
NVRAM
Displays the configuration currently
running in RAM
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THANK YOU
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