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 name of the data unit at the data link layer?

  1. AFrame
  2. BMessage
  3. CPacket
  4. DSegment
2.Easy

What does LAN stand for?

  1. ALinked application node
  2. BLocal area network
  3. CLogical address number
  4. DLarge access network
3.Easy

Which protocol is used to send email between mail servers?

  1. ASNMP
  2. BSMTP
  3. CPOP3
  4. DIMAP
4.Medium

What is the purpose of the TCP three-way handshake?

  1. ATo close a connection quickly
  2. BTo establish a connection and synchronise sequence numbers
  3. CTo encrypt the data
  4. DTo find the IP address of a host before data can be sent to it
5.Medium

How many usable host addresses does a /26 IPv4 subnet have?

  1. A64
  2. B30
  3. C126
  4. D62
6.Medium

How does TLS typically use asymmetric and symmetric cryptography?

  1. AOnly asymmetric cryptography is used throughout
  2. BSymmetric methods agree keys and authenticate; asymmetric ciphers encrypt all the data
  3. COnly symmetric cryptography is used, with a fixed shared password
  4. DAsymmetric methods agree keys and authenticate; symmetric ciphers encrypt the data
7.Hard

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

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

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

  1. A3 kbit/s
  2. B24 kbit/s
  3. C12 kbit/s
  4. D6 kbit/s

Answer key

  1. 1. A · Frame
  2. 2. B · Local area network
  3. 3. B · SMTP
  4. 4. B · To establish a connection and synchronise sequence numbers
  5. 5. D · 62
  6. 6. D · Asymmetric methods agree keys and authenticate; symmetric ciphers encrypt the data
  7. 7. A · Victims send traffic for the gateway to the attacker, enabling a man-in-the-middle attack
  8. 8. C · 12 kbit/s

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