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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1.Easy

Which protocol is used to send email between mail servers?

  1. ASNMP
  2. BPOP3
  3. CSMTP
  4. DIMAP
2.Easy

Which IPv4 address is the standard loopback address of a host?

  1. A255.255.255.255
  2. B192.168.0.1
  3. C127.0.0.1
  4. D0.0.0.0
3.Easy

What does DNS do?

  1. AEncrypts web traffic
  2. BRoutes packets between networks
  3. CAssigns IP addresses to devices automatically
  4. DTranslates domain names into IP addresses
4.Medium

At which OSI layer does a switch normally operate?

  1. AData link (layer 2)
  2. BTransport (layer 4)
  3. CNetwork (layer 3)
  4. DPhysical (layer 1)
5.Medium

TLS provides which security properties for HTTPS?

  1. AOnly faster loading
  2. BAnonymity of the user
  3. CConfidentiality, integrity and server authentication
  4. DProtection against all malware and phishing on the visited site
6.Medium

What is a cyclic redundancy check (CRC) used for in Ethernet frames?

  1. ADetecting transmission errors
  2. BCorrecting every bit error automatically
  3. CChoosing the best route
  4. DEncrypting the frame
7.Hard

With sliding-window protocols, how does Go-Back-N differ from Selective Repeat after one frame is lost?

  1. ABoth resend the whole window from the start
  2. BNeither ever resends lost frames
  3. CGo-Back-N resends the lost frame and all later ones; Selective Repeat only the lost one
  4. DGo-Back-N resends only the lost frame; Selective Repeat resends that frame and all later ones
8.Hard

Why does a browser warn when a site presents a self-signed certificate?

  1. AThe site must be using HTTP instead of HTTPS
  2. BThe certificate is always expired
  3. CSelf-signed certificates use no encryption at all, so the traffic is sent in clear text
  4. DNo trusted certificate authority vouches that the key belongs to that site

Answer key

  1. 1. C · SMTP
  2. 2. C · 127.0.0.1
  3. 3. D · Translates domain names into IP addresses
  4. 4. A · Data link (layer 2)
  5. 5. C · Confidentiality, integrity and server authentication
  6. 6. A · Detecting transmission errors
  7. 7. C · Go-Back-N resends the lost frame and all later ones; Selective Repeat only the lost one
  8. 8. D · No trusted certificate authority vouches that the key belongs to that site

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