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

  1. ANetwork layer
  2. BSession layer
  3. CData link layer
  4. DPhysical layer
2.Easy

What is the default port number for HTTPS?

  1. A443
  2. B80
  3. C25
  4. D21
3.Easy

Which protocol is used to send email between mail servers?

  1. AIMAP
  2. BSNMP
  3. CPOP3
  4. DSMTP
4.Medium

How many usable host addresses does a /26 IPv4 subnet have?

  1. A126
  2. B64
  3. C30
  4. D62
5.Medium

What is the role of a default gateway on a host?

  1. AIt is the router used for traffic to other networks
  2. BIt is the switch port the host is connected to
  3. CIt is the DNS server
  4. DIt assigns MAC addresses
6.Medium

What uniquely identifies one end of a TCP connection on the internet?

  1. AA MAC address alone
  2. BA domain name alone
  3. CAn IP address together with a port number
  4. DA subnet mask and gateway
7.Hard

An 8-port switch (no VLANs) has one host on each port. How many collision domains and broadcast domains are there?

  1. A8 collision domains, 1 broadcast domain
  2. B1 collision domain, 1 broadcast domain
  3. C8 collision domains, 8 broadcast domains
  4. D1 collision domain, 8 broadcast domains
8.Hard

A student runs a game server on a PC behind a home NAT router. Friends on the internet cannot connect. What is the usual fix?

  1. AConfigure port forwarding on the router to the PC's private address
  2. BGive the PC a different MAC address so the router can find it from outside
  3. CChange the PC's subnet mask to /32
  4. DTurn off the PC's DNS client

Answer key

  1. 1. D · Physical layer
  2. 2. A · 443
  3. 3. D · SMTP
  4. 4. D · 62
  5. 5. A · It is the router used for traffic to other networks
  6. 6. C · An IP address together with a port number
  7. 7. A · 8 collision domains, 1 broadcast domain
  8. 8. A · Configure port forwarding on the router to the PC's private address

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