12.6.2.2 describe the role of MAC addresses in packet routing
12.6.2.3 identify the MAC address of a computer
MAC address
Every computer device (PC, smartphone, laptop, printer or other device which is capable of being part of network) must have a Network Interface Card (NIC). Each NIC has a unique Media Access Control address (MAC address).
MAC Address operates in the Data link layer.
A MAC address is a hardware identification number that uniquely identifies each device on one segment of the network.
The address is 48 bits long, and is represented as 12 hex digits, for example
0A-1F-57-E2-B4-83
Switches use MAC addresses to determine which station the data packet is destined for.
Functions of MAC address:
MAC Address is used to ensure the physical address of computer.
MAC Address helps in simply identifying the device.
Features of using MAC address:
MAC Address operates in the data link layer.
MAC Address of computer cannot be changed with time and environment.
Unlike an IP address, a MAC address cannot be easily found by a third party.
How to determine MAC address on a computer using Command Promt?
Press the key combination Win + R
Input cmd and press Enter
Input command ipconfig /all
Look at physical address of Ethernet adapter of Wi-Fi
To find out the MAC address on your smartphone, go to Settings - Wi-Fi - Advanced settings.
“Garbage cans were placed all over the city, and Wi-Fi monitoring hardware was installed in them. Then, the garbage cans were networked together. When you walked by one of these garbage cans, your device would send probe requests with its MAC address and the garbage can’s sniffer would make a note of the MAC address and its location. When you walked by another garbage can, it would note your device’s MAC address and location again. This information could be combined to form a picture of your movements throughout the day. Advertisers would know the areas you visited and could try to target ads specifically to you. With enough Wi-Fi sensors joined together, it would be possible to track your smartphone’s complete movements over an entire day.”
A store could place Wi-Fi sniffers throughout their store and log MAC addresses. Perhaps you spent some time in the electronics section before leaving for another section of the store — the store could display ads for electronics to you.
Security services and police can track the movements of individuals they are interested in.
Ex 1. Define MAC address of your PC and smartphone.
Ex 2. Do some research to find out how you can change the MAC address of your PC. Why might someone want to do this?
Ex 3.
Ex 4. Correct mistakes
Exam questions:
Question.
A student claims that "an individual piece of hardware may be tracked and identified by its MAC address.
Explain briefly how MAC address is used and state whether you agree with the statement above(Marks: 3)
Answer. The student is largely correct. For example, when you walk around with a smartphone, it scans for nearby Wi-Fi networks (1) and broadcasts its MAC address (1). However, in some network interfaces, the MAC address is set in software and can be changed (1), though this would be unusual.
