IP addressing is a crucial part of computer networks and a frequently tested topic in UPSC EPFO APFC examinations. Understanding IP address classes, ranges, subnetting basics, and related concepts helps candidates score high in the computer knowledge section.
Below are 30 carefully curated MCQs to strengthen your preparation.

1. Which of the following is the range of Class A IP addresses?

A. 0.0.0.0 – 127.255.255.255
B. 128.0.0.0 – 191.255.255.255
C. 192.168.0.0 – 192.168.255.255
D. 224.0.0.0 – 239.255.255.255

Answer: A
Explanation: Class A ranges from 0–127 as the first octet. It supports very large networks with millions of hosts.

2. The private IP address range for Class C is:

A. 192.168.0.0 – 192.168.255.255
B. 172.16.0.0 – 172.31.255.255
C. 10.0.0.0 – 10.255.255.255
D. 169.254.0.0 – 169.254.255.255

Answer: A
Explanation: Class C private range starts with 192.168.x.x, used in most home routers. It supports small networks.

3. Which IP class is used for multicast addressing?

A. Class A
B. Class B
C. Class C
D. Class D

Answer: D
Explanation: Class D (224–239) is specifically reserved for multicast operations. It does not have host addresses.

4. 127.0.0.1 is used for:

A. Default Gateway
B. Loopback Testing
C. Broadcast Address
D. Subnetting

Answer: B
Explanation: 127.0.0.1 is the loopback address used to test the local machine. It doesn’t route over the network.

5. The range of Class B IP addresses is:

A. 1–126
B. 128–191
C. 192–223
D. 224–239

Answer: B
Explanation: Class B begins at 128 and ends at 191, suitable for medium-sized networks.

6. The default subnet mask for Class A is:

A. 255.0.0.0
B. 255.255.0.0
C. 255.255.255.0
D. 255.255.255.252

Answer: A
Explanation: Class A uses 255.0.0.0, providing a huge number of hosts. Only the first octet is the network portion.

7. Which IP class provides 24 bits for hosts?

A. Class A
B. Class B
C. Class C
D. Class D

Answer: A
Explanation: Class A allocates 24 host bits, supporting over 16 million hosts per network.

8. The range of Class C IP addresses is:

A. 128–191
B. 192–223
C. 224–239
D. 0–127

Answer: B
Explanation: Class C starts at 192 and ends at 223, typically used for small networks.

9. 255.255.255.255 is known as:

A. Private address
B. Default gateway
C. Limited broadcast address
D. Loopback address

Answer: C
Explanation: 255.255.255.255 is used to broadcast to all hosts on the network. It is a special-purpose address.

10. A private Class A IP address range is:

A. 172.16.x.x
B. 10.x.x.x
C. 192.168.x.x
D. 169.254.x.x

Answer: B
Explanation: 10.x.x.x is the designated private range for Class A. It is used in internal networks.

11. APIPA addresses range from

A. 10.x.x.x
B. 172.16.x.x
C. 192.168.x.x
D. 169.254.x.x

Answer: D
Explanation: APIPA automatically assigns 169.254.x.x if DHCP fails. It enables minimal local connectivity.

12. Which protocol assigns IP addresses dynamically?

A. DNS
B. DHCP
C. FTP
D. SMTP

Answer: B
Explanation: DHCP automatically assigns IP addresses to devices. It simplifies network administration.

13. IP addresses are part of which layer in OSI model?

A. Data Link
B. Transport
C. Network
D. Application

Answer: C
Explanation: IP addressing is a function of the Network layer (Layer 3). It handles routing and addressing.

14. Which address identifies a specific network device

A. MAC Address
B. IP Address
C. Subnet Mask
D. Broadcast Address

Answer: B
Explanation: An IP address uniquely identifies a device on a network. It enables communication across networks.

15. IPv4 uses how many bits?

A. 16 bits
B. 32 bits
C. 64 bits
D. 128 bits

Answer: B
Explanation: IPv4 uses a 32-bit addressing scheme. It provides about 4.3 billion unique addresses.

16. An IPv4 address is divided into:

A. 8 octets
B. 4 octets
C. 6 octets
D. 2 octets

Answer: B
Explanation: IPv4 consists of 4 octets, each ranging from 0 to 255. They represent binary values.

17. Public IP addresses are assigned by:

A. IANA
B. IEEE
C. ICANN
D. ISO

Answer: C
Explanation: ICANN manages global public IP address allocation. It oversees domain and address systems.

18. The loopback IP address range is:

A. 1.0.0.0 – 1.255.255.255
B. 127.0.0.0 – 127.255.255.255
C. 192.168.0.0 – 192.168.255.255
D. 224.0.0.0 – 239.255.255.255

Answer: B
Explanation: Entire 127.x.x.x range is reserved for loopback testing. 127.0.0.1 is the most used.

19. What is the binary form of 255?

A. 10000000
B. 00000001
C. 11111111
D. 00001111

Answer: C
Explanation: 255 in decimal equals 11111111 in binary. It indicates all bits are set.

20. What type of address is 224.0.0.5?

A. Multicast
B. Broadcast
C. Unicast
D. Private

Answer: A
Explanation: Addresses starting from 224 fall under multicast. They are used in group communications.

21. A subnet mask helps in identifying:

A. Default gateway
B. Network and host portion
C. DNS server
D. MAC address

Answer: B
Explanation: Subnet masks separate the network and host parts of an IP address. It supports subnetting.

22. 192.0.2.0 is an example of:

A. Private IP
B. Documentation/test IP
C. Multicast IP
D. Loopback IP

Answer: B
Explanation: 192.0.2.0 is reserved for documentation and examples, not real networking.

23. IPv6 addresses contain how many bits?

A. 32
B. 64
C. 128
D. 256

Answer: C
Explanation: IPv6 uses 128-bit addressing, offering a vast number of unique addresses.

24. What is the maximum value of one IPv4 octet?

A. 128
B. 64
C. 255
D. 512

Answer: C
Explanation: Each octet ranges 0–255 because it represents 8 binary bits.

25. 255.255.0.0 is the subnet mask of which class?

A. Class A
B. Class B
C. Class C
D. Class D

Answer: B
Explanation: Class B default mask is 255.255.0.0. It supports medium-sized networks.

26. 172.20.0.0 belongs to which private range?

A. Class A
B. Class B
C. Class C
D. Class D

Answer: B
Explanation: 172.16–172.31 is the private Class B range. 172.20 falls within it.

27. A globally unique IP address is called:

A. Private IP
B. Broadcast IP
C. Public IP
D. Loopback IP

Answer: C
Explanation: Public IP addresses are routable on the internet. They are unique worldwide.

28. Which IP belongs to Class A?

A. 200.10.5.1
B. 150.10.1.2
C. 100.20.30.40
D. 250.10.10.10

Answer: C
Explanation: 100 falls in the 0–127 range, thus Class A. It supports large networks.

29. What is the main purpose of subnetting?

A. Increase speed
B. Reduce cables
C. Divide networks
D. Create websites

Answer: C
Explanation: Subnetting divides a network into smaller segments. It improves efficiency and security.

30. The first address of any network is the:

A. Host address
B. Broadcast address
C. Network address
D. Loopback

Answer: C
Explanation: The network address identifies the network itself. It cannot be assigned to devices.

Conclusion

Understanding IP address ranges and related concepts is fundamental for UPSC EPFO APFC aspirants. These 30 MCQs cover essential exam-oriented points, such as classes, private ranges, subnetting, and special-purpose addresses.
Revise these questions regularly to strengthen your computer awareness and improve your exam performance.