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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1.Easy

How is an IPv6 address usually written?

  1. AEight groups of four hexadecimal digits separated by colons
  2. BSixteen decimal numbers separated by dots
  3. CFour decimal numbers separated by dots
  4. DSix pairs of hexadecimal digits separated by dashes or colons
2.Easy

What does a packet header mainly contain?

  1. AThe website's text and images
  2. BControl information such as source and destination addresses
  3. CThe user's actual file contents, split into equal-sized pieces
  4. DThe cable type used for the link
3.Easy

What is the default port number for HTTPS?

  1. A443
  2. B80
  3. C21
  4. D25
4.Medium

Which medium access method did classic shared (half-duplex) Ethernet use?

  1. ACSMA/CA
  2. BCSMA/CD
  3. CTDMA
  4. DToken passing
5.Medium

Why does Wi-Fi use collision avoidance (CSMA/CA) instead of collision detection?

  1. ACollision detection only works on fibre cables, not on shared wireless radio channels
  2. BWi-Fi only allows one device per network
  3. CRadio signals never collide
  4. DA wireless station cannot reliably detect collisions while it is transmitting
6.Medium

How does TLS typically use asymmetric and symmetric cryptography?

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

TCP congestion control's "slow start" phase:

  1. AKeeps the window fixed at one segment
  2. BIs used only by UDP
  3. CIncreases the congestion window exponentially until a threshold or loss
  4. DHalves the congestion window every round trip until a packet loss is detected
8.Hard

A student runs a game server on a PC behind a home NAT router. Friends on the internet cannot connect. What is the usual fix?

  1. AChange the PC's subnet mask to /32
  2. BTurn off the PC's DNS client
  3. CGive the PC a different MAC address so the router can find it from outside
  4. DConfigure port forwarding on the router to the PC's private address

Answer key

  1. 1. A · Eight groups of four hexadecimal digits separated by colons
  2. 2. B · Control information such as source and destination addresses
  3. 3. A · 443
  4. 4. B · CSMA/CD
  5. 5. D · A wireless station cannot reliably detect collisions while it is transmitting
  6. 6. C · Asymmetric methods agree keys and authenticate; symmetric ciphers encrypt the data
  7. 7. C · Increases the congestion window exponentially until a threshold or loss
  8. 8. D · Configure port forwarding on the router to the PC's private address

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