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

A MAC address identifies:

  1. AA website
  2. BA network interface on the local link
  3. CA user account
  4. DA router's public IP
2.Easy

What is throughput?

  1. AThe number of routers on a path
  2. BThe time a packet takes to cross a link
  3. CThe rate at which data is actually delivered successfully
  4. DThe theoretical maximum rate a link can carry under ideal conditions
3.Easy

Which protocol gives secure, encrypted remote login to another computer?

  1. ASSH
  2. BSNMP
  3. CTelnet
  4. DFTP
4.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. A10.0.0.0/8, because it covers more addresses than the /16
  2. BBoth routes, splitting the traffic equally
  3. C10.0.0.0/8, because it was added first
  4. D10.1.0.0/16, because it is the longest matching prefix
5.Medium

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

  1. A0–65535
  2. B1024–49151
  3. C49152–65535
  4. D0–1023
6.Medium

NAT (network address translation) is mainly used to:

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

A path has 100 Mbit/s bandwidth and a 40 ms round-trip time. How much data must be in flight to keep it fully used?

  1. A4 kB
  2. B500 kB
  3. C50 kB
  4. D2.5 MB
8.Hard

Why does the side that closes a TCP connection first stay in the TIME_WAIT state for twice the maximum segment lifetime?

  1. ATo keep the encryption keys for later reuse
  2. BTo let the routers along the path update their routing tables for the next connection
  3. CTo wait for the DNS cache to expire
  4. DSo delayed segments die out and the final ACK can be resent if it was lost

Answer key

  1. 1. B · A network interface on the local link
  2. 2. C · The rate at which data is actually delivered successfully
  3. 3. A · SSH
  4. 4. D · 10.1.0.0/16, because it is the longest matching prefix
  5. 5. D · 0–1023
  6. 6. C · Let many devices with private addresses share one public IP address
  7. 7. B · 500 kB
  8. 8. D · So delayed segments die out and the final ACK can be resent if it was lost

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