Lesson 4.9.4.3

4.9.4.3 IP address structure and subnet masking Quiz: AQA Computer Science, Unit 9

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.9.4.3, IP address structure and subnet masking: 20 multiple choice questions for the AQA Computer Science (7517), Unit 9: Fundamentals of communication and networking, written with Revision Ninja.

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The 20 questions

  1. An IP address is split into two parts. Which pair describes them?

    • A network identifier and a host identifier.
    • A protocol identifier and a port number that together select the correct service on the destination host.
    • A domain name and a file path.
    • A MAC address and a subnet mask.

  2. How many bits does an IPv4 address contain?

    • 128
    • 16
    • 64
    • 32

  3. What is the purpose of the network identifier part of an IP address?

    • It identifies the device's position in the order of packets sent.
    • It identifies the physical manufacturer of the network card.
    • It identifies which network the device belongs to.
    • It identifies the application that sent the packet.

  4. What is the function of a subnet mask?

    • To give each device a unique MAC address on the local network.
    • To encrypt the host part of an IP address before transmission, so that only the destination router can decode it.
    • To identify which bits of an IP address form the network identifier part.
    • To count the number of packets sent by a host each second.

  5. In an IPv4 subnet mask, which bits are set to 1?

    • Every bit, so that the mask matches all addresses in the network.
    • The bits that form the network identifier part of the address.
    • The bits that count the number of hosts currently connected to the subnet.
    • The bits that identify the individual host on the subnet.

  6. What is the network address for 192.168.1.37 with subnet mask 255.255.255.0?

    • 192.168.1.37
    • 192.168.1.255
    • 192.168.0.0
    • 192.168.1.0

  7. What is the network address for 10.20.30.40 with subnet mask 255.0.0.0?

    • 10.20.0.0
    • 10.20.30.0
    • 40.0.0.0
    • 10.0.0.0

  8. What is the network address for 172.16.5.9 with subnet mask 255.255.0.0?

    • 172.16.5.9
    • 172.0.0.0
    • 172.16.0.0
    • 172.16.5.0

  9. How many usable host addresses are there in a subnet with mask 255.255.255.0?

    • 256
    • 255
    • 252
    • 254

  10. How many usable host addresses are there in a subnet with mask 255.255.255.192?

    • 60
    • 30
    • 64
    • 62

  11. Devices 192.168.1.5 and 192.168.2.5 both use mask 255.255.255.0. Which statement is true?

    • They are on different subnets, so they cannot reach each other directly without a router.
    • They are on the same subnet because both addresses end in the digit 5.
    • They share the network identifier 192.168.0.0 and so are on the same subnet, which means a router is not needed between them.
    • They are on the same subnet because both devices use the same subnet mask.

  12. Which of these is a valid IPv4 subnet mask?

    • 255.255.255.0
    • 255.255.0.255
    • 255.0.255.0
    • 255.255.255.256

  13. A host has IP address 192.168.10.200 and mask 255.255.255.240. What is its network address?

    • 192.168.10.200
    • 192.168.10.192
    • 192.168.10.0
    • 192.168.10.128

  14. A network needs at least 50 host addresses. Which subnet mask gives the smallest suitable subnet?

    • 255.255.255.224
    • 255.255.255.192
    • 255.255.255.240
    • 255.255.255.128

  15. Host 10.1.2.3 uses mask 255.255.0.0. Which of these addresses is on the same subnet?

    • 11.1.2.3
    • 10.2.2.3
    • 10.1.200.9
    • 10.0.2.3

  16. Why does subnetting make large networks easier to manage?

    • It increases the length of IPv4 addresses from 32 bits to 64 bits.
    • It limits broadcast traffic to each subnet and lets an organisation group devices logically.
    • It removes the need for a host identifier in each IP address.
    • It gives every device a permanent public IP address from the ISP.

  17. Which part of an IPv4 address do routers use to decide which network a packet should be sent to?

    • The last octet only, regardless of the subnet mask.
    • The MAC address stored in the packet header.
    • The network identifier part.
    • The host identifier part.

  18. What is the broadcast address for the network 192.168.1.0 with mask 255.255.255.0?

    • 192.168.1.0
    • 192.168.0.255
    • 192.168.1.255
    • 192.168.1.254

  19. An administrator uses a /29 subnet, mask 255.255.255.248, for 6 devices. Is this adequate?

    • Yes, but only because the mask puts 29 ones into the host part of the address, which leaves exactly six usable addresses for hosts.
    • No, a /29 subnet gives 14 usable host addresses, which is too many to manage.
    • No, it gives only 4 usable host addresses, which is far too few.
    • Yes, it gives 6 usable host addresses, which is exactly enough for the devices.

  20. A subnet mask of 255.255.255.128 is applied to 200.100.50.25. What is the network address?

    • 200.100.50.128
    • 200.100.50.25
    • 200.100.0.0
    • 200.100.50.0

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