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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy

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

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

What is the main job of a firewall?

  1. ATo speed up downloads by caching files
  2. BTo convert domain names into addresses
  3. CTo assign IP addresses to hosts
  4. DTo allow or block traffic according to security rules
3.Easy

What is encapsulation in layered networking?

  1. AEncrypting all data before sending it
  2. BCompressing packets to save bandwidth
  3. CEach layer removes the header added by the layer above before sending
  4. DEach layer adds its own header to the data from the layer above
4.Medium

Which DNS record type maps a host name to an IPv6 address?

  1. AAAAA
  2. BA
  3. CMX
  4. DCNAME
5.Medium

Which of these is a private IPv4 address range?

  1. A200.1.1.0/24
  2. B100.0.0.0/8
  3. C192.168.0.0/16
  4. D8.8.8.0/24
6.Medium

A router has routes for 10.0.0.0/8 and 10.1.0.0/16. Which route does it use for a packet to 10.1.5.5?

  1. ABoth routes, splitting the traffic equally
  2. B10.0.0.0/8, because it was added first
  3. C10.1.0.0/16, because it is the longest matching prefix
  4. D10.0.0.0/8, because it covers more addresses than the /16
7.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
8.Hard

Why does TCP choose an unpredictable initial sequence number for each connection?

  1. ATo compress the data more efficiently
  2. BTo avoid confusion with old segments and make spoofed segments harder to inject
  3. CTo select the best route to the destination for the segments of that connection
  4. DTo encrypt the payload of each segment

Answer key

  1. 1. A · A router
  2. 2. D · To allow or block traffic according to security rules
  3. 3. D · Each layer adds its own header to the data from the layer above
  4. 4. A · AAAA
  5. 5. C · 192.168.0.0/16
  6. 6. C · 10.1.0.0/16, because it is the longest matching prefix
  7. 7. C · 12 kbit/s
  8. 8. B · To avoid confusion with old segments and make spoofed segments harder to inject

Full step-by-step solutions: practise this topic on examproblems.com.