School of Engineering Technology and Applied Science

Department of Information and Communication Engineering Technology

Computer Systems and Network

Friday, April 24, 2015

Workshop on Setting up a Wireless/WiFi Network

Instructor: Ali Nezhad

Computer Systems and Networks Programs

Centennial College

Computer and Communication Networks Bachelor Degree (CCN)

Computer Systems Technology – Networking (CSTyN)

Computer Systems Technician – Networking (CSTN)

Computer Repair And Maintenance Certificate (CRAM)

What makes Centennial Different …?

Accredited Programs

o Canadian Technology Accreditation Board (CCTT/CTAB)

Co-op

Hands-on

State-of-the-Art Labs

Full Spectrum of Programs

Program Coordinator:

Dr. Ali Al-Rubaie

(416) 289-5000 ext. 3434

aalrubaie@centennialcollege.ca

Page 2 of 13

Objectives:

Learn how to create/set up a wireless network at home/school so that you can use your desktop/laptop/smart phone to access the Internet remotely and securely.

Network Topology

We find Wireless/WiFi networks everywhere; at schools, hospitals, Tim Hortons and homes. To build a WiFi network, all that we need is a Wireless Router/Access Point (AP), which is normally connected to the Internet through one of the Internet Service Providers like Bell or Rogers. To be able to connect to the Wireless Router, user devices, like PC, laptop, tablet PC and Smart phones, should be equipped with a wireless/WiFi interface. The topology of this network is shown below:

Page 3 of 13

Lab Tasks:

Network device factory default recovery Basic wireless router configuration Configure laptops and Smart phones to access the router Configure Security key on the router and wireless computers Configure MAC address filtering Extend wireless range using additional routers

Team and Duration:Three to five students per team per lab session (90 minutes)

Page 4 of 13

Introduction to Computer Addressing:

1. MAC (Medium Access Control) Address

Physical or Hardware Address

Each purchased PC, laptop, tablet PC or Smart Phone has its own Unique and Permanent MAC address

Has Local Significance only; can be used to communicate only with other users in the same local network. For example, each Centennial student has a unique student no. which is recognized only inside Centennial and does not have any meaning for your Family Doctor, your bank or Canada revenue agency.

2. IP (Internet Protocol) Address

Logical, or Software, Address

A Unique and Temporal Address assigned to your device when you join a network like School network, Tim Hortons network, network at home, …etc. It will be taken away from you when you leave the School, Tim Hortons or Home.

Has Global Significance; can be used to communicate with any user on the Internet.For Example, the SIN is Unique and has a Significance on the National level; it is recognized all over Canada, not only in the School, the Family Doctor office or your bank branch.

Lab Procedure:

A. Basic Wireless Setup

1. Connect the PC to any of the four Ethernet ports at the back panel of the Wireless Router Linksys WRT120N router (as shown in the figure below) using one Ethernet (UTP) cable. The Laptop and Smart Phone will be used to join the Wireless network

Page 5 of 13

Wireless Laptop/Smart Phone Linksys WRT120N Wired PC

2. Power on wireless router Linksys WRT120N, press the Reset button for over 2 seconds. Then, your wireless router will have factory default settings. The default password is recovered (default password: admin, no username)

3. After connecting your PC to any of wireless router’s four ports, check if your PC has retrieved IP address from the router by the following steps:

a. Click Windows Start button, then key in “cmd” command in “Search programs and files” field. You will see the following Window:

b. In the command line, key in “ipconfig” command to verify your IP address. Do you have 192.168.1.X IP address in the command output (X is a value in the range 101 to 140)? If yes, move on to the next step. If not, repeat step 1 and check again.

4. Start your PC’s Browser (IE, Firefox, or Chrome), key in 192.168.1.1 in the Brower’s Web link field.

Page 6 of 13

5. You will see Linksys WRT120N authentication page. Key in password as admin, leave username blank.

6. Now, you should be able to see Linksys WRT120N graphic interface as show below. Congratulations, you can now configure the router for your own wireless network establishment.

7. Click “Wireless” option on the left top field. You can now see the following interface.

Page 7 of 13

Check "Manual" in "Configuration View", then you will see:

Key in a new name in Network Name (SSID) field, list the name here: __________(for example, funnet, each group should have a different name).Make sure that the option “SSID Broadcast” is set to Enabled and then click "Save Settings".

Note: In the last part of this workshop, every two groups will be paired and perform an experiment jointly. It is recommended that if one group names their network funnet the peer group name theirs funnet-extender.

B. Check the Wireless Connection

8. Now, let’s work on the Laptop and learn how to join the wireless network that you just set:

a. Click the wireless network icon, shown below, at the bottom-right corner of the screen and read available networks.

Page 8 of 13

b. Select your network with the wireless network name you set in step 4 (SSID name), if you do not find it then click Refresh Network List. Click Connect and You are Connected! Note how the Wireless Network icon had been changed to indicate that you are connected.

9. Now, let’s work on the Smart Phone (Samsung) and learn how to join the wireless network that you just set:

a. Select the Setting group then select Wi-Fi, you will see a list of available WiFi networks.

b. Select your network with the wireless network name you set in step 4 (SSID name), click Connect. You are Connected!

C. Test Internet connectivity.At home or in the office, you would have an Internet connection through your ISP (Internet Service

Provider). In the college, we are not allowed to connect your router to the college network for security

reasons. Instead, we will use a local server to emulate the Internet.

Your instructor has already prepared the setup in a way that you can connect to the server

plustwo.setasicet.int by plugging the uplink port of your router into one of the yellow ports behind the

monitors on your desk.

Now, you should be able to connect to the server by starting a browser on your cell phone or the

laptop and typing the server name plustwo.setasicet.int.

D. How about Security?

You may have noticed that at this time anyone can connect to the WiFi network configured in the previous steps. No password or security constraints have been configured. You definitely do not want your network to be available to unauthorized users like neighbors or hackers; they will share your Internet bandwidth which will downgrade the Internet connection speed and could also be a security and privacy concern.

Page 9 of 13

In the following steps, you will learn how to define some security constraints and configure a secure WiFi network.

10. Click "Wireless Security", you will note that Security is disabled by default. Pull down “Security Mode”:

There are different Security modes listed there and we will select "WPA Personal" in this lab.

After selecting this mode, you may get the following message:

Click OK.

Key in Passphrase (8-63 characters long): ___________, this is a Password or Access Key that you will have to provide in order to connect to the WiFi network. For example, you may use myPass123 as a passphrase.Click "Save Settings"

Check the Connection:

11. Now, let’s work on the Laptop and learn how to join the secure wireless network that you just set:

a. First, you will notice that your laptop had been disconnected automatically from the network

Page 10 of 13

after configuring the Security mode and Passphrase.

b. Click the network connection icon at the bottom-right corner of the screen and view available networks.

c. Click on the wireless network with the name you set in step 4 (SSID name), click Connect.

d. You will be asked to provide the Password that you defined in step 10. Type the Password and You are Connected

12. Now, let’s work on the Samsung Smart Phone and learn how to join the secure wireless network that you just set:

a. As with the Laptop configuration above, you will notice that your Smart Phone had been disconnected automatically from the network after configuring the Security mode and Passphrase.

b. Select the Setting group then select Wi-Fi, you will see a list of available WiFi networks.

c. Select your network. You will be asked to provide a Password. Type in the Password that you configured in step 10 and You are Connected!

E. One More Step in Building a Secure Network – MAC Filtering

As we mentioned in the Introduction, each PC/Laptop/Smart Phone has a unique MAC address that no other device can have. So, to make your network more secure, you can define which device has the right to connect to your network using its MAC address as the device ID. That way, the router will allow ONLY devices with those MAC addresses and block all other devices.

13. Click "Wireless MAC filter", you will see the following:

14. Click "Enabled" option, you can select either the devices you want to block or those you want to permit. In most cases we use the later. Check "Permit"

15. You can add the MAC addresses manually. The MAC addresses can be found as follows

Page 11 of 13

a. For Laptop, go to START Run cmd ok. Then, type ipconfig/all, scroll to the Ethernet Adapter Wireless Network Connection and find there the Physical Address which is the MAC address. What is your Laptop MAC Address? _______________________________

b. For Smart Phone, go to Settings Wi-Fi Advanced and you will find the MAC address

there. What is your Smart Phone MAC Address? _______________________________

16. Since the Laptop and Smart Phone had been already connected to the Wireless Router, the Router is aware of their MAC addresses. Click "Wireless Client List" and you will get the devices MAC addresses. Compare these addresses with the MAC addresses you wrote down above, they should be exactly the same.

17. Let’s select to save only the Laptop (dell) MAC address by clicking on the corresponding box in the list, click on Add and then Save Settings.

a. Is the laptop still connected?

b. How about the Smart Phone

F. Range Extension

The coverage area of a wireless router or access point depends on a number of factors such as its

supported standard (.11 a/b/g/n/ac), its antennas and in particular its location. Wireless signals can be

weakened by distance and objects like walls and other obstacles. Even the type of materials used in walls

is important. Therefore, in any wireless network there may be dark spots where the signal levels are low

which means the connection will be either unusable or at least the transmission rate will be low.

To improve the situation a secondary wireless device may be used. There are many names to describe

such a device which may mean slightly different things. Some of these names are signal booster (a.k.a

range extender), router, repeater, bridge or an access point.

An economical solution may exist if you have a second wireless router which may not be in use at the

moment such as an older model which you retired after buying your new unit. This is possible by

connecting the second router in one of several possible configurations to the first router.

Although the two routers may be connected wirelessly (which may be desirable), for the sake of simplicity,

in this lab we will connect them using an Ethernet cable. For a wireless configuration, the firmware of the

second router (if even amongst the supported models; at this time it seems that our WRT120n routers are

not supported.) must usually be upgraded using software such as DD-WRT, Tomato or OpenWRT.

The following figure depicts the scenario for the next experiment. In this setup, the second router will also

work as an actual router not just a wireless access point or a repeater.

Page 12 of 13

18. Team up with the group sitting next to you. If one group has the funnet network, the other group will

own the funnet-extender.

19. Disconnect the Internet port of the funnet-extender router from the ISP (yellow jack behind the

monitor) and connect it to one of the LAN ports of the funnet using a straight through cable.

20. In order to simulate a realistic situation, you may wrap the funnet router in some aluminum foil. In

that case, its signal should be considerably weakened so that your devices may not be able to

successfully connect to the server using that router anymore (you may need to clear your browser

cache). Now, try connecting your devices to funnet-extender and try loading the same server web

page or pinging it again. Were you successful?

21. Free practice and document for future reference.

Page 13 of 13

funnet-extender funnet

ISP

BasementFamily Room

Internet Port

InternetPort

LANPort