Back
Next
Restart
1  Pepperoni for Kate 1  Cheese for Molly & Jane 1  Veggie for Jose 1  Veggie for John
Understanding the Use of MAC Addressing Within a Network and IP Addressing Outside of a Network
You are having some friends over your house and you are ordering pizza for everyone. So you gather everyone’s name and their orders and write them down on a piece of paper.
2/17
1/17
Understanding the Use of MAC Addressing within a Network and IP Addressing Outside of a Network
This material was developed with funding from the National Science Foundation under Grant # DUE 1601612
Changes if you move to a new network
Does not change – “burned” into computer
172.16.11.154
76-97-25-FD-EC-C7
1 Pepperoni for Kate 1 Cheese for Molly & Jane 1 Veggie for Jose 1 Veggie for John
3/17
When you call to order a pizza you give the restaurant the order for the entire house rolling up all the orders into one. Your request for pizza leaves your home when you make the phone call and is passed to the restaurant.
1 Pepperoni  1 Cheese 2 Veggie
This is similar to the time when you used your computer to access Google while your friend was also using the local area network (LAN) to try to access a different website.
Close 
4/17
Website homepage request for 34-E7-D4-81-B5-F2 Website homepage request for 54-E3-D2-65-A1-E2
Local Area Network (LAN) a collection of computers, and other devices that share a common network connection and exist in a limited geographic area, usually within a building.
Wide Area Network (WAN) a collection of computers, and other devices that share a common network connection and exist in a large geographic area, and generally connects multiple local area networks (LANs).
Your router gathers these requests and sends them out across the Internet to their intended locations. The request for the website homepages leaves your local area network (LAN) when the router passes the information through the wide area network (WAN) of other Internet routers and ultimately to the websites’ web servers.
Router a networking device that forwards data packets between computer networks.
5/17
Internet
You give the pizza restaurant your home address (street number, street, and city) to deliver the pizza to. This is the same as providing to the websites web servers the public IP address of the default gateway to your network to deliver the website homepages to.
Default Gateway an access point or router that a computer on the same network uses to send information to a computer on another network or the internet.
Public IP Address: 172.31.255.255
6/17
Internet Protocol (IP) Address is a unique address that identifies a device on the Internet or a local network.
Address: 525 Main Street Boston, MA
The delivery man is required to deliver to the door of your home using the home address. The pizza delivery man isn’t interested in who will get the pizza or how you will divide up the pizza once he has completed his task of bringing it to the home address.
7/17
Public IP Address: 172.31.255.255
8/17
The pizza delivery person just needs your address to deliver the pizza. Similarly, the routers along the way just need the public IP address of the default gateway. The routers are not interested in who will get the web address request once it is brought to the default gateway IP address.
Once the pizza is inside your home, you will divide up the pizzas and give them to the people within the home. But how do you deliver them to the right person? Each person has a unique identifier, usually use their name. You check your order and use their name to get the pizza to the right person.
9/17
10/17
   Glossary Terms
The default gateway router will give the web page request to the computers within the network that request them. Each computer (device) has a unique identifier, their  MAC address, to get the web page request to the right computer.
Local Area Network (LAN) a collection of computers, and other devices that share a common network connection and exist in a limited geographic area, usually within a building. Wide Area Network (WAN) a collection of computers, and other devices that share a common network connection and exist in a large geographic area, and generally connects multiple local area networks (LANs). Router a networking device that forwards data packets between computer networks. Internet Protocol (IP) Address is a unique address that identifies a device on the Internet or a local network. Default Gateway an access point or router that a computer on the same network uses to send information to a computer on another network or the internet. Media Access Control (MAC) Address unique static address of a device assigned at the time of manufacture.
Media Access Control (MAC) Address unique static address of a device assigned at the time of manufacture.
Glossary Terms
At the Pizza Shop
Click on each pizza and drag to the corresponding pizza order. Ordering pizza is similar to when you use your computer to access Google while your friend is also using the local area network (LAN) to try to access a different website. All the orders are rolled up into one for each house.
11/17
Good Job!  Click Next to continue.
27 South Street
The City
35 Main Street
12/17
Click on each order and drag to the correct delivery location. The pizza delivery person just needs your address to deliver the pizza. Similarly, the routers along the way just need the public IP address of the default gateway.
12 Water Street
The Kitchen of Each Home
Click on each pizza and drag to the plate of the correct person. Once the pizza is inside your home, you will divide up the pizzas and give them to the people within the home by checking their name. Similarly each computer (device) has a unique identifier, their MAC address, to get the web page request to the right computer.
13/17
NAME
The Google Server
Google Web Server
Click on each web page result and drag to matching envelope. When you request a website homepage, you give the web server all the orders for the entire address as one order.
14/17
Google
172.31.255.255
184.27.101.163
Click on each website request (manila envelopes) and drag to the correct network router/gateway device. Routers just need the public IP address of the default gateway. The routers are not interested in who will get the web address request once it is brought to the default gateway IP address.
196.12.201.102
The Internet
15/17
Click on each data packet (web page) and drag to the matching Mac address. The default gateway router will give the web page request to the computers within the network that request them. Each computer (device) has a unique identifier, their MAC address, to get the web page request to the right computer.
Inside Each Network
Mac Address 34-E7-D4-81-B5-F2
Mac Address 32-C1-E2-42-A8-B7
16/17
Mac Address 94-B1-A2-86-F3-B8
Mac Address 82-F2-C4-46-B1-E4
Mac Address 85-F0-B8-41-B7-F8
Mac Address 36-B3-A5-99-C4-E1
Congratulations! You completed the exercise.
17/17