MAC addressing in Computer Networks - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the sentence to define a MAC address.

Computer Networks

A MAC address is a unique identifier assigned to a [1] interface.

Drag options to blanks, or click blank then click option'

Asoftware

Buser

Capplication

Dnetwork

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing MAC address with IP address

Thinking MAC is assigned to software

A MAC address uniquely identifies a network interface on a device.

2fill in blank

medium

Complete the sentence about the format of a MAC address.

Computer Networks

A MAC address is usually represented as six groups of two hexadecimal digits separated by [1].

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Acommas

Bspaces

Ccolons

Dperiods

Attempts:

3 left

💡 Hint

Common Mistakes

Using commas or spaces as separators

Confusing with IP address format

MAC addresses are commonly shown with colons separating each pair of hexadecimal digits, like 00:1A:2B:3C:4D:5E.

3fill in blank

hard

Fix the error in the statement about MAC address length.

Computer Networks

A MAC address is [1] bits long.

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A48

B128

C64

D32

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing MAC length with IPv4 or IPv6 address length

Choosing 32 or 64 bits

A MAC address is 48 bits long, which equals 6 bytes.

4fill in blank

hard

Fill both blanks to describe the MAC address parts.

Computer Networks

The first [1] bytes of a MAC address identify the manufacturer, called the [2].

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A3

B5

COUI

DIP

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing OUI with IP

Using wrong byte count

The first 3 bytes of a MAC address are the OUI (Organizationally Unique Identifier), which identifies the manufacturer.

5fill in blank

hard

Fill all three blanks to complete the MAC address usage description.

Computer Networks

MAC addresses operate at the [1] layer, are [2] assigned, and help devices communicate within a [3].

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Anetwork

Buniquely

Clocal network

Ddata link

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing network layer with data link

Thinking MAC addresses are dynamically assigned

MAC addresses work at the data link layer, are uniquely assigned by manufacturers, and help devices communicate within a local network.

Practice

1. What does a MAC address uniquely identify in a computer network?

easy

A. A network protocol type

B. An IP address on the internet

C. A website domain name

D. A device on a local network

Solution

1. Step 1: Understand the role of MAC addresses

   A MAC address is a unique identifier assigned to network interfaces for communications on the physical network segment.

2. Step 2: Identify what MAC addresses represent

   They identify devices on a local network, not IP addresses or domain names.

3. Final Answer:

   A device on a local network -> Option D

4. Quick Check:

   MAC address = device ID on local network [OK]

Hint: MAC addresses identify devices locally, not IPs or domains [OK]

Common Mistakes:

• Confusing MAC address with IP address
• Thinking MAC identifies websites
• Assuming MAC is a protocol

2. Which of the following is the correct format of a MAC address?

easy

A. 00:1A:2B:3C:4D:5E

B. 192.168.1.1

C. 255.255.255.0

D. http://192.168.1.1

Solution

1. Step 1: Recognize MAC address format

   MAC addresses are shown as six pairs of hexadecimal numbers separated by colons or dashes.

2. Step 2: Match the correct format

   00:1A:2B:3C:4D:5E matches this format: six pairs separated by colons with hex digits.

3. Final Answer:

   00:1A:2B:3C:4D:5E -> Option A

4. Quick Check:

   MAC format = hex pairs separated by colons [OK]

Hint: Look for six hex pairs separated by colons or dashes [OK]

Common Mistakes:

• Confusing MAC with IP address format
• Including URL or protocol parts
• Using decimal numbers instead of hex

3. Given the MAC address AC:DE:48:00:11:22, which part typically identifies the manufacturer?

medium

A. 00:11:22

B. 48:00:11

C. AC:DE:48

D. DE:48:00

Solution

1. Step 1: Understand MAC address structure

   The first three pairs (first 24 bits) of a MAC address identify the manufacturer, called the OUI (Organizationally Unique Identifier).

2. Step 2: Identify the first three pairs

   In AC:DE:48:00:11:22, the first three pairs are AC:DE:48, which represent the manufacturer.

3. Final Answer:

   AC:DE:48 -> Option C

4. Quick Check:

   First 3 pairs = manufacturer ID [OK]

Hint: First 3 hex pairs in MAC show manufacturer [OK]

Common Mistakes:

• Choosing last three pairs as manufacturer
• Mixing pairs in the middle
• Not knowing OUI meaning

4. A network admin sees a MAC address written as 00-1G-2B-3C-4D-5E. What is wrong with this MAC address?

medium

A. It is missing pairs

B. It has an invalid character 'G'

C. It uses colons instead of dashes

D. It has too many pairs

Solution

1. Step 1: Check valid characters in MAC address

   MAC addresses use hexadecimal digits: 0-9 and A-F only.

2. Step 2: Identify invalid character

   The character 'G' is not a valid hex digit, so the MAC address is invalid.

3. Final Answer:

   It has an invalid character 'G' -> Option B

4. Quick Check:

   Hex digits only: 0-9, A-F [OK]

Hint: MAC uses hex digits only; watch for invalid letters [OK]

Common Mistakes:

• Ignoring invalid hex characters
• Confusing dashes and colons as errors
• Counting pairs incorrectly

5. You want to filter a list of devices to only those from a specific manufacturer with OUI 00:1A:2B. Which method best uses MAC addresses to do this?

hard

A. Check if the MAC address starts with '00:1A:2B'

B. Check if the MAC address ends with '00:1A:2B'

C. Check if the MAC address contains '2B:00:1A'

D. Check if the MAC address has '00:1A:2B' anywhere in the middle

Solution

1. Step 1: Understand OUI position in MAC address

   The OUI is always the first three pairs of the MAC address, identifying the manufacturer.

2. Step 2: Choose the correct filtering method

   To filter devices by manufacturer, check if the MAC address starts with the OUI '00:1A:2B'.

3. Final Answer:

   Check if the MAC address starts with '00:1A:2B' -> Option A

4. Quick Check:

   OUI = start of MAC address [OK]

Hint: Filter by checking MAC start for OUI [OK]

Common Mistakes:

• Checking MAC end instead of start
• Looking for OUI in the middle
• Assuming OUI can be anywhere