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

How many bits does an IPv4 address have?

  1. A32
  2. B64
  3. C16
  4. D128
2.Easy

What does a packet header mainly contain?

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

How many layers does the OSI reference model have?

  1. A4
  2. B9
  3. C7
  4. D5
4.Medium

Which IPv4 header field stops packets from circulating forever in a routing loop?

  1. ATime to live (TTL)
  2. BType of service
  3. CHeader checksum
  4. DIdentification
5.Medium

What is the IPv6 loopback address?

  1. Aff02::1
  2. B::
  3. C::1
  4. Dfe80::1
6.Medium

A signal travels 2000 km through fibre at about 2 × 10⁸ m/s. What is the propagation delay?

  1. A10 ms
  2. B0.1 ms
  3. C100 ms
  4. D1 ms
7.Hard

With sliding-window protocols, how does Go-Back-N differ from Selective Repeat after one frame is lost?

  1. ANeither ever resends lost frames
  2. BGo-Back-N resends only the lost frame; Selective Repeat resends that frame and all later ones
  3. CBoth resend the whole window from the start
  4. DGo-Back-N resends the lost frame and all later ones; Selective Repeat only the lost one
8.Hard

In a TCP connection, what does the receive window (rwnd) control?

  1. AThe number of open ports
  2. BThe size of each IP packet header
  3. CHow much unacknowledged data the sender may send, based on the receiver's buffer
  4. DThe retransmission time-out, calculated from the measured round-trip time of each segment

Answer key

  1. 1. A · 32
  2. 2. D · Control information such as source and destination addresses
  3. 3. C · 7
  4. 4. A · Time to live (TTL)
  5. 5. C · ::1
  6. 6. A · 10 ms
  7. 7. D · Go-Back-N resends the lost frame and all later ones; Selective Repeat only the lost one
  8. 8. C · How much unacknowledged data the sender may send, based on the receiver's buffer

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