Vaidikalaya

MCQ On classless-ip-addressing

Q1. What is the primary goal of classless addressing?.
  1. Increase the number of classes
  2. Reduce routing table size
  3. Remove subnet masks
  4. Expand Class A networks

Answer: b, Reduce routing table size

Solution: CIDR reduces routing table entries through aggregation.

Q2. Classless addressing represents IP addresses using which notation?.
  1. Dotted decimal only
  2. Hexadecimal
  3. Prefix notation (e.g., /24)
  4. Binary string

Answer: c, Prefix notation (e.g., /24)

Solution: CIDR uses prefix length notation.

Q3. Which technology allows creation of subnets with varying sizes?.
  1. RIP v1
  2. VLSM
  3. ARP
  4. DHCP

Answer: b, VLSM

Solution: VLSM allows flexible subnet sizes.

Q4. The full form of CIDR is:.
  1. Classful Internet Domain Routing
  2. Classless Inter-Domain Routing
  3. Computer Inter-Domain Routing
  4. Central Internet Data Routing

Answer: b, Classless Inter-Domain Routing

Solution: CIDR = Classless Inter-Domain Routing.

Q5. Which notation is used in CIDR?.
  1. Hexadecimal addressing
  2. Prefix notation like /24
  3. Only class A/B/C format
  4. Binary octet notation

Answer: b, Prefix notation like /24

Solution: CIDR uses prefixes (e.g., 192.168.1.0/24).

Q6. What does the '/18' in 10.0.0.0/18 represent?.
  1. Number of hosts
  2. Number of subnets
  3. Bits used for network portion
  4. Bits used for host portion

Answer: c, Bits used for network portion

Solution: /18 means first 18 bits are network bits.

Q7. Which statement is TRUE about CIDR?.
  1. It increases IP wastage
  2. It removes the need for subnetting
  3. It allows aggregation of multiple networks
  4. It is used only in IPv6

Answer: c, It allows aggregation of multiple networks

Solution: CIDR supports route aggregation.

Q8. Classless addressing replaces which traditional method?.
  1. DNS
  2. Classful addressing
  3. MAC addressing
  4. ARP resolution

Answer: b, Classful addressing

Solution: CIDR overcame the limitations of classful addressing.

Q9. What is the main reason Classless addressing was introduced?.
  1. Improve Wi-Fi bandwidth
  2. Slow down routing
  3. Avoid IPv6
  4. Prevent IPv4 address wastage

Answer: d, Prevent IPv4 address wastage

Solution: CIDR allocates only required IPs.

Q10. In classless addressing, what does /16 represent?.
  1. 16 hosts
  2. 16 networks
  3. 16 bits for network portion
  4. 16 bits for host portion

Answer: c, 16 bits for network portion

Solution: /16 means 16 bits define the network.

Q11. Which routing protocol supports CIDR?.
  1. RIP v1
  2. IGRP
  3. RIP v2
  4. Early ARPANET

Answer: c, RIP v2

Solution: RIP v2 is classless and supports CIDR.

Q12. CIDR aggregates IP networks into what is called:.
  1. VLAN
  2. Supernet
  3. Subnet
  4. Broadcast domain

Answer: b, Supernet

Solution: CIDR supernets combine routes.

Q13. Which advantage is specific to classless addressing?.
  1. Fixed block sizes
  2. Faster hardware processing
  3. Flexible subnetting
  4. Automatic IP allocation

Answer: c, Flexible subnetting

Solution: CIDR/VLSM allow custom subnet sizes.

Q14. In CIDR, an address block with /30 prefix length provides how many usable hosts?.
  1. 2
  2. 4
  3. 6
  4. 14

Answer: a, 2

Solution: /30 gives 4 addresses, 2 usable.

Q15. Which of the following is NOT true about classless addressing?.
  1. It allows route aggregation
  2. It reduces IP address wastage
  3. It uses fixed subnet masks
  4. It supports VLSM

Answer: c, It uses fixed subnet masks

Solution: CIDR does NOT use fixed masks.

Q16. In classless addressing, how is the number of hosts determined?.
  1. 2^(prefix)
  2. 2^(32 – prefix) – 2
  3. Prefix × 32
  4. 32 – 2

Answer: b, 2^(32 – prefix) – 2

Solution: Host bits = 32 – prefix.

Q17. Which of the following is an example of CIDR notation?.
  1. 192.168.1.0 mask 255.255.255.0
  2. 192.168.1.0/24
  3. 192.168.1.0 class C
  4. 192.168.1.0 netmask C

Answer: b, 192.168.1.0/24

Solution: CIDR format is IP + prefix (/24).

Q18. Which protocol benefits MOST from route summarization in classless addressing?.
  1. ARP
  2. OSPF
  3. DNS
  4. DHCP

Answer: b, OSPF

Solution: OSPF uses hierarchical routing and summary routes.

Q19. What is the technique of combining multiple networks into one called in CIDR?.
  1. Subnetting
  2. Supernetting
  3. Broadcasting
  4. Mapping

Answer: b, Supernetting

Solution: CIDR supernets multiple networks for aggregation.