Aoraki Digital Technologies/Level 2/DT 2.50 AS91377/Make and Test a Simple LAN

Make and test a simple LAN

Purpose

The purpose of this activity is to make and test a simple Local Area Network (LAN).  We will use this simple LAN as a basis of many experiments so ensure you are familiar with making it!

What to do

Your teacher will provide you with the following equipment:

• a switch
• a hub
• some ethernet cables
• between 3 and 5 computers
• some zenix live cd's

Make the LAN

Working in groups (no more than 2 people per computer) make the following simple network.  This has been described using zenix but you could equally do it in Windows.  We use zenix because it has some great networking tools on it that we will use later on.

1. Firstly, each computer should be attached to the switch using a network cable
2. Boot each computer into zenix from the live CD
3. First, turn off the zenix firewall by right-clicking on the desktop, choose Security -> Firewall and untick "Enabled".
4. Next, set the computers ip address between 10.168.11.5 through to 10.168.11.10.  These are pronounced "ten dot one six eight dot eleven dot five".  No two computers on your simple LAN should have the same ip address.  So if you had 3 computers on your mini LAN they would have the addresses 10.168.11.5, 10.168.11.6 and 10.168.11.7 .
   • Do this by Left clicking the small icon that looks like a pair of screen in the very bottom right hand corner of the Zenix desktop.
   • This will bring up the Wicd networking configuration window. Click on "properties".In the next dialogue, tick "Use Static IP's" and enter the ip address from above ( between 10.168.11.5 through to 10.168.11.10)
   • Click in the line below "Netmask" and accept the defaults.
   • Click OK in the bottom of this window
   • Back in the original Wicd window press disconnect and then connect. This will refresh you network settings.
   • Your teacher will show you how to do this

• Zenix network configuration screenshots
• 

  Figure 1. Open the Wicd network configuration manager by clicking on the double screen icon; click to view closer

• 

  Figure 2. Click on the properties icon; click to view closer.

• 

  Figure 3. Set the ip address; click to view closer.

Test the LAN 

1. Open up a terminal by right clicking on the desktop, selecting "terminal" and run the ifconfig command by typing in "sudo ifconfig" and press enter - what does it tell you? (In windows the command is ipconfig).  
2. In the terminal try the ping command to "ping" another computer on your LAN. To stop the ping command use ctrl ctrl c .  Alternatively try limiting the ping command using -c 10 option. - what does ping do? (More details on the ping tool are here http://en.wikibooks.org/wiki/Computer_Networks/Ping)
3. Now change the ip addresses to the following pattern: 10.168.12.5, 10.168.13.6, 10.168.14.7 ... note the change in the pattern (.12' .13, .14 etc)
4. Repeat the ping test - what happens now?
5. Later on we will try and explain these results