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 type of cable carries data as pulses of light?

  1. AFibre-optic cable
  2. BShielded copper cable
  3. CCoaxial cable
  4. DTwisted-pair cable
2.Easy

What is the main job of a firewall?

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

What is the default port number for HTTPS?

  1. A80
  2. B25
  3. C443
  4. D21
4.Medium

What is the network address of the host 192.168.10.77/26?

  1. A192.168.10.76
  2. B192.168.10.128
  3. C192.168.10.0
  4. D192.168.10.64
5.Medium

HTTP is stateless. How do websites usually keep a user logged in across requests?

  1. AWith cookies holding a session identifier or token
  2. BBy storing the password in the URL
  3. CBy keeping the TCP connection open for days
  4. DBy giving each user a fixed IP address
6.Medium

What does an MX record in DNS specify?

  1. AAn alias name for another host
  2. BThe mail servers that accept email for a domain
  3. CThe IPv4 address of a web server
  4. DThe name servers for a zone
7.Hard

What does TCP fast retransmit do?

  1. AResends a segment after three duplicate ACKs, without waiting for the timeout
  2. BResends every segment twice to be safe
  3. CDoubles the window after every loss
  4. DSkips the three-way handshake when reconnecting to known hosts, so data is resent sooner
8.Hard

A DNS cache poisoning attack aims to:

  1. ASteal Wi-Fi passwords
  2. BDelete DNS servers
  3. CMake a resolver store a false IP address for a domain
  4. DOverload a server with traffic so that it stops answering queries

Answer key

  1. 1. A · Fibre-optic cable
  2. 2. A · To allow or block traffic according to security rules
  3. 3. C · 443
  4. 4. D · 192.168.10.64
  5. 5. A · With cookies holding a session identifier or token
  6. 6. B · The mail servers that accept email for a domain
  7. 7. A · Resends a segment after three duplicate ACKs, without waiting for the timeout
  8. 8. C · Make a resolver store a false IP address for a domain

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