Computer networks worksheet with answers

Free printable Computer networks worksheet: 8 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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Name: ____________________   Date: ____________

1.Easy

What is the broadcast address of the network 192.168.1.0/24?

  1. A255.255.255.0
  2. B192.168.1.0
  3. C192.168.1.255
  4. D192.168.1.1
2.Easy

Which device forwards packets between different networks based on IP addresses?

  1. AA hub
  2. BA repeater
  3. CA switch
  4. DA router
3.Easy

How many bits does an IPv4 address have?

  1. A64
  2. B16
  3. C32
  4. D128
4.Medium

What is a cyclic redundancy check (CRC) used for in Ethernet frames?

  1. ADetecting transmission errors
  2. BChoosing the best route
  3. CEncrypting the frame
  4. DCorrecting every bit error automatically
5.Medium

What is the network address of the host 192.168.10.77/26?

  1. A192.168.10.0
  2. B192.168.10.64
  3. C192.168.10.128
  4. D192.168.10.76
6.Medium

Which single prefix summarises both 192.168.0.0/24 and 192.168.1.0/24?

  1. A192.168.0.0/25
  2. B192.168.1.0/23
  3. C192.168.0.0/22
  4. D192.168.0.0/23
7.Hard

An attacker on a LAN sends forged ARP replies claiming the gateway's IP address. What is the likely result?

  1. AAll DNS queries fail across the internet
  2. BThe gateway's IP address is permanently changed to the attacker's address on every router
  3. CVictims send traffic for the gateway to the attacker, enabling a man-in-the-middle attack
  4. DThe switch shuts down all of its ports
8.Hard

By the Nyquist formula, what is the maximum bit rate of a noiseless 3 kHz channel using 4 signal levels?

  1. A24 kbit/s
  2. B12 kbit/s
  3. C3 kbit/s
  4. D6 kbit/s

Answer key

  1. 1. C · 192.168.1.255
  2. 2. D · A router
  3. 3. C · 32
  4. 4. A · Detecting transmission errors
  5. 5. B · 192.168.10.64
  6. 6. D · 192.168.0.0/23
  7. 7. C · Victims send traffic for the gateway to the attacker, enabling a man-in-the-middle attack
  8. 8. B · 12 kbit/s

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