COMP3371 Session 3 Practical

COMP3371 Session 3 Practical

regarding Packet Switching

Reminder from last week…

To show current running-configuration, type:

router# show running-config

To save the running configuration and overwrite the startup configuration, type:

router# copy running-config startup-config

Use these commands as you consider appropriate…

Exercise 3(a) More Router Configuration using the CLI

Assigning a device name to the router (e.g. R1)

Open the packet tracer file with router and switch that you saved last week, and go to the router’s CLI dialogue.
Enter global configuration mode. (if you’ve forgotten, this is achieved by typing configure terminal within privileged mode)

The prompt will change to include (config) #

Now type hostname R1

The prompt name in front of the prompt should change to R1

DNS Lookup is important to prevent the router from attempting to translate incorrectly entered commands as though they were host names.

To disable this option, type no ip domain-lookup

To secure access to the various privileged access levels, passwords are needed and logons need to be set up!

enable password… create password with weak/reversible encryption

enable secret… create password with strong/non-reversible encryption

CISCO recommends the enable secret command because it uses an improved encryption algorithm. If you configure the enable secret command, it takes precedence over the enable password command; the two commands cannot be in effect simultaneously.

Still in (config) # mode, type enable secret x1y1z1

(where x1y1z1 is the the privileged EXEC encrypted password.)

Protecting configuration via console

There is yet another mode for configuring access to the console… (config-line) mode.

Type line console 0

Notice the change in prompt.

Now type password x3y2z1 to assign this as the console password
Finally type login to enable login. Without this it wouldn’t even be possible to be prompted for a password!

Exercise 3(b) Configuring the Switch

Have a go at doing the following to configure the switch. Use packet tracer help to assist you…

Go into CLI mode on the switch

Turn on CLI commands by typing enable
Entering global configuration mode
Assigning the switch hostname.
Assign class as the privileged EXEC encrypted password.
Assign cisco as the console password and enable login.
Encrypt the clear text passwords.
Prevent unwanted Domain Name System (DNS) lookups.
Configure a login message-of-the-day (MOTD) banner.
Enter global configuration mode to set the SVI (VLAN 1) IP address to allow remote switch management.
Configure IP default gateway.
Save the running configuration to the startup configuration file.
Save and Exit the packet tracer file.

Open a new packet tracer window

Add two switches and two PCs….

Name the two switches S1 and S2.

Connect one end of an Ethernet cable to F0/1 on S1 and the other end of the cable to F0/1 on S2. You should see the lights for F0/1 on both switches turn amber and then green. This indicates that the switches have been connected correctly.

Connect one end of the second Ethernet cable to the NIC port on PC-A. Connect the other end of the cable to F0/6 on S1. After connecting the PC to the switch, you should see the light for F0/6 turn amber and then green, indicating that PC-A has been connected correctly.

Now, connect one end of the last Ethernet cable to the NIC port on PC-B. Connect the other end of the cable to F0/18 on S2.

After connecting the PC to the switch, you should see the light for F0/18 turn amber and then green, indicating that the PC-B has been connected correctly.

Double-click on PC-A then PC-B in turn to give each a static IP address (192.168.10.10 and 192.168.10.11 respectively). Each should also have a default subnet mask of 255.255.255.0. Leave default gateway blank each time

Go to the DOS prompt command on the PC-A window, and use ipconfig to check the IP configurations of PC-A. Repeat for PC-B

Now try to ping PC-B’s IP address using the ping command.

Repeat for pinging PC-A from PC-B.