WELCOME TO
Basic Router Configuration
1.1 Global configuration
• Cisco allows us to configure the router to
support various protocols and interfaces.
• The router stores the configuration in the
configuration file .
To enter global configuration
during boot:
1. Boot the router after installation . The CLI or
the Command Line Interface appears.
2. Type enable or en to switch to the
privileged mode. The #.Command prompt
appears.
3. Type setup to run the System
Configuration dialog.
On CISCO 2620 Router
4: Type Y
5: Press Enter. The Router Prompts you to
select if you want to view the interface
summary.
6: Type yes.
7: Press Enter . The router enters global
configuration.
1.2 Router Administrative
Functions
 The administrative function such as assigning
hostnames , banners , setting password and
interface descriptions allow you to configure
a router in the network . These function
allows easy troubleshooting and
maintenance of routers.
1.2.1 Assigning Hostname
 The hostname command allows you to
change the router hostname . The default
assigned during router installation is Router.
The hostname command operates at the
configuration mode in CLI of the router . The
syntax of the command is:
hostname name
Where name specifies the name of the router.
To change the router
hostname:
1. Open the router CLI .
2. Type enable or en to switch to the privileged
mode .
3. Type Config t to switch to the configuration
mode . The config#. Command prompt
appears.
4. Type hostname UIET’s_Router to configure a
hostname for the router where , is the name of
the router.
5. Press Enter . The router name changes to
UIET’s_Router
UIET’s Router
1.2.2 Banners
 A banner is a message displayed to all the users
when they access the router through Telnet ,
Console and auxiliary ports.
1. Open the CLI.
2. Switch to the configuration mode.
3. Type banner motd z and press Enter , Now
type message like:-Welcome to UIET’s
Router z and press Enter.
4. The login banner is visible next time the user
can see it .
Display banner name
1.2.3 Setting Passwords
1.
2.
3.
4.
5.
The router has three type of ports , console ,
telnet and auxiliary. You can configure
passwords for each port.
On Console mode.
VTY mode
AUX mode
0 level password
5 level password
To Set Console Password
1. Open the CLI
2. Switch to the configuration mode.
3. Type line console 0 to switch to the console
port:
4. Press Enter
5. Type password password1 and press Enter.
6. Type Login and press Enter.
7. Type exit and press Enter to quit from the
console
On Console Mode
Telnet Password
 Telnet password provides access to the telnet services . To set the

1.
2.
3.
4.
5.
6.
7.
telnet password you must switch to the telnet using line vty
command.
To configure VTY passwords:
Open the CLI.
Switch to the configuration mode.
Type line vty 0 4 to switch to telnet.
Press Enter. The (config-line)# command prompt appears.
Type password mypas to set a password for the console ,
where , mypas represents the telnet password for the router.
Press Enter.
Type login to log on to the telnet . Press Enter.
Type exit to quit from telnet .
Telnet Mode
Auxiliary Password
 Auxiliary password are required for accessing interface
1.
2.
3.
4.
5.
6.
connected to the auxiliary port . You can not set this
password for routers that do not have the auxiliary port.
Open the CLI
Switch to the configuration mode .
Type line aux 0 to switch to the auxiliary port. Press
Enter.
Type password mypas to set a password for the auxiliary
port , where , mypas represents the auxiliary password for
the router
Press Enter.
Type exit to exit from the console.
Auxiliary Mode
0 Level password
 Any person can see our password . It can be
see on RAM by show run command.
1. Router>enable
2. Router>config t
3. Router(config)#enable password uiet
4. Router(config)#exit
Why we enable 0 level
password:
 0 level password provide security on privilege
mode when user go from user executive
mode to Privilege mode then router wants
user access verification for go on privilege
mode .Its only works when console mode
password is enable .
On Router:-
5 level Password
 In 0 level password any person can see our
password by show run command. But by 5
level password any person can not see our
password .
 In o level password type this : uiet’s_Router#show run
 Press Enter.
When 5 level password is
enable
when we enable 5 level password and run show
run command on router , then it shows the o
level password but in encrypted form.
1.3 Router Interface
 An interface provide connection between the
user and the network.
 The interface are connected to the ports of
the CISCO routers . The ports are aligned into
different slots of the router . The slots and
port numbers starts from 0. we can use the
interface command to configure router
interface.
For example:-
1.3.1 Activate an Interface
 If we use the router’s interface port then we must
have to activate the interface port. Because all port
of router is default off .
 To turn on the router interface:1. Open the CLI.
2. Switch to the privileged mode.
3. Switch to the configuration mode.
4. Type interface s1/0 to switch to the interface
serial 1/0.
5. Type no shutdown to bring up the interface.
6. Press ctrl+z to come out of the configuration
mode.
1.3.2 Configuring IP address
on an Interface
 We must plan our network before configuring
the IP addresses . We need to calculate the
subnet mask for the network . After
calculating the subnet masks, we have to
decide the router IP addresses.
To configure IP address for
the router Interface:1. Open the CLI.
2. Switch to the configuration mode.
3. Type interface fastethernet 0/0 to configure the
fast ethernet interface for the port 0/0/
4. Type ip address 10.0.0.1 255.0.0.0 to configure
the IP address for this interface , where 10.0.0.1
indicates the IP address and 255.0.0.0 indicates
the subnet mask.
5. Press Enter.
6. Press ctrl+z to come out of the configuration
mode.
1.4 Router Configurations
 Whenever we change the router configuration , it is
required to save the changes to the configuration
files . This router losses the modified configuration
on reload or power failure , if the changes are not
saved . The configuration files also contain the
commands that are used to configure the router .
These files are of two types running configuration
and startup configuration . The configuration files
are located in the RAM,NVRAM or TFTP server. The
currently operating configuration of the router is
located in RAM . The backup and saved
configuration are either located in NVRAM or TFTP
server.
1.4.1 Creating Configuration
File
 We can create a new configuration file or the
router from the CLI . We need to enter the
privileged mode to begin the configuration of
the router . The actual configuration is
performed in the configuration mode .
 The configuration of the router includes:
 Enabling routing
 Configuring different interfaces
 Configuring routing protocols
To create an empty
Configuration File:
1. Open the CLI.
2. Switch to the privileged mode.
3. Type config t to switch to the configuration
mode .
4. Press Enter. The command prompt changes to
(config)#.
5. Type exit o complete the configuration.
6. Type copy running-config startup-config to save
the configuration as the default startupconfiguration file or the router.
Router prompt
1.4.2 Viewing Configuration
Files
 The configuration file for the router can be
displayed using the show command from the
privileged mode . To view the configuration
file , we need to open the CLI of the router
and switch to the privileged mode . We can
use the following commands to view the
configuration files:
 To view startup configuration file , type show
startup-config in the command prompt.
1.4.3 Saving Configuration
File:
 The configuration changes that we make to
the router are saved to the current
configuration file. These changes will not
reflect in the router , when the router
reboots. To apply changes , when the router
restarts, the changes need to saved in the
running-config file .
1.4.4 Erasing Configuration
Files
 We can delete the existing configuration files for
the router using the erase command. The erase
command removes the startup-config file from
the NVRAM.
 To delete a configuration file:
 Open the CLI .
 Switch to the privileged mode.
 Type erase stratup-config to delete the startupconfig file from the NVRAM.
 Type show startup-config to verify
whether the configuration file is delete .