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 layers does the OSI reference model have?

  1. A5
  2. B9
  3. C4
  4. D7
2.Easy

What does a VPN mainly provide?

  1. AAn encrypted tunnel across an untrusted network such as the internet
  2. BAutomatic backup of files to a server
  3. CA faster physical connection to the internet through a dedicated line
  4. DA free public IP address for every device
3.Easy

In which network topology is every device connected to one central switch or hub?

  1. ARing
  2. BFull mesh
  3. CBus
  4. DStar
4.Medium

Which protocol does the "ping" command use?

  1. AICMP
  2. BTCP
  3. CUDP
  4. DHTTP
5.Medium

Which range of TCP/UDP port numbers is reserved as "well-known" ports?

  1. A49152–65535
  2. B0–65535
  3. C1024–49151
  4. D0–1023
6.Medium

NAT (network address translation) is mainly used to:

  1. ATranslate domain names into IP addresses for devices on a local network
  2. BEncrypt traffic between two sites
  3. CLet many devices with private addresses share one public IP address
  4. DIncrease the speed of a network cable
7.Hard

A DNS cache poisoning attack aims to:

  1. AMake a resolver store a false IP address for a domain
  2. BSteal Wi-Fi passwords
  3. CDelete DNS servers
  4. DOverload a server with traffic so that it stops answering queries
8.Hard

What is the main benefit of persistent connections (keep-alive) in HTTP/1.1?

  1. AThe server can push updates over UDP
  2. BResponses can arrive in any order on one stream, so slow replies do not block others
  3. CThe connection stays encrypted without TLS
  4. DSeveral requests reuse one TCP connection, avoiding repeated handshakes

Answer key

  1. 1. D · 7
  2. 2. A · An encrypted tunnel across an untrusted network such as the internet
  3. 3. D · Star
  4. 4. A · ICMP
  5. 5. D · 0–1023
  6. 6. C · Let many devices with private addresses share one public IP address
  7. 7. A · Make a resolver store a false IP address for a domain
  8. 8. D · Several requests reuse one TCP connection, avoiding repeated handshakes

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