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

Which device simply repeats every incoming signal out of all its other ports?

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

Which OSI layer transmits raw bits as electrical, optical or radio signals?

  1. ANetwork layer
  2. BSession layer
  3. CPhysical layer
  4. DData link layer
3.Easy

Which transport protocol provides reliable, ordered delivery with acknowledgements?

  1. AUDP
  2. BIP
  3. CICMP
  4. DTCP
4.Medium

Which subnet mask corresponds to /20?

  1. A255.255.240.0
  2. B255.255.248.0
  3. C255.255.255.240
  4. D255.255.224.0
5.Medium

What is the usual order of messages when a client obtains an address from DHCP?

  1. ADiscover, Offer, Request, Acknowledge
  2. BDiscover, Request, Offer, Acknowledge
  3. COffer, Discover, Acknowledge, Request
  4. DRequest, Offer, Discover, Acknowledge
6.Medium

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

  1. AHeader checksum
  2. BType of service
  3. CTime to live (TTL)
  4. DIdentification
7.Hard

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

  1. A6 kbit/s
  2. B24 kbit/s
  3. C12 kbit/s
  4. D3 kbit/s
8.Hard

Why was the TCP window scale option introduced?

  1. AUDP needed a way to control its sending rate on congested paths
  2. BWithout it, TCP could not detect lost segments on long-distance links
  3. CThe 32-bit window field was too large and wasted header space in every TCP segment sent
  4. DThe 16-bit window field limits the window to 65,535 bytes, too small for fast long-distance paths

Answer key

  1. 1. C · A hub
  2. 2. C · Physical layer
  3. 3. D · TCP
  4. 4. A · 255.255.240.0
  5. 5. A · Discover, Offer, Request, Acknowledge
  6. 6. C · Time to live (TTL)
  7. 7. C · 12 kbit/s
  8. 8. D · The 16-bit window field limits the window to 65,535 bytes, too small for fast long-distance paths

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