Which are true regarding IP address allocation?

Which are true regarding IP address allocation?

• A. All IP addresses on a network must be unique except when anycast is used
• B. IPv4 addresses are classified into Classes A, B, and C
• C. The mask length of /24 can simplify network design
• D. Variable length subnet mask (VLSM) is used for efficient IP address allocation

Answer: (A)

Regarding IP address allocation, asserting that all IP addresses on a network must be unique, except when anycast is used, highlights a crucial principle in networking. In most scenarios, a network is designed to ensure that each device has a distinct IP address; this uniqueness is essential for proper communication and routing of data within that network. Anycast addressing, however, allows multiple devices to share the same IP address. In anycast, data sent to a specific address is routed to the nearest device (from the perspective of the routing topology) that holds that address. This method enhances efficiency and redundancy, especially useful in content delivery networks and certain applications where the closest node is desired without requiring strict uniqueness of the address. While the other statements touch on relevant concepts in IP address allocation, they do not accurately encapsulate the uniqueness requirement as comprehensively as the statement regarding anycast. For instance, while it is true that IPv4 addresses can be categorized into classes, this classification is somewhat outdated with the introduction of Classless Inter-Domain Routing (CIDR). Similarly, while the mask length of /24 can simplify network design, emphasizing a common subnetting practice, this simplification applies only in certain scenarios and does not inherently relate to the uniqueness of IP addresses.

Regarding IP address allocation, asserting that all IP addresses on a network must be unique, except when anycast is used, highlights a crucial principle in networking. In most scenarios, a network is designed to ensure that each device has a distinct IP address; this uniqueness is essential for proper communication and routing of data within that network. Anycast addressing, however, allows multiple devices to share the same IP address. In anycast, data sent to a specific address is routed to the nearest device (from the perspective of the routing topology) that holds that address. This method enhances efficiency and redundancy, especially useful in content delivery networks and certain applications where the closest node is desired without requiring strict uniqueness of the address.

While the other statements touch on relevant concepts in IP address allocation, they do not accurately encapsulate the uniqueness requirement as comprehensively as the statement regarding anycast. For instance, while it is true that IPv4 addresses can be categorized into classes, this classification is somewhat outdated with the introduction of Classless Inter-Domain Routing (CIDR). Similarly, while the mask length of /24 can simplify network design, emphasizing a common subnetting practice, this simplification applies only in certain scenarios and does not inherently relate to the uniqueness of IP addresses.