CIDR notation expresses an IP address and its subnet mask using which statement?

CIDR notation expresses an IP address and its subnet mask using which statement?

• A. CIDR replaces classful routing
• B. NAT replaces classful routing
• C. DHCP replaces classful routing
• D. ARP replaces classful routing

Answer: (A)

CIDR notation expresses an IP address and its subnet mask by appending a slash and the number of network bits after the address (for example, 192.168.0.0/16). The slash-prefixed value shows exactly how many leading bits are the network portion, which lets you define any prefix length rather than sticking to the fixed masks of classful addressing. This flexibility supports more efficient use of IP space and enables route aggregation, reducing the size of routing tables. The idea behind CIDR is to move away from rigid class-based addressing toward flexible prefixes that match actual network needs. The other options describe technologies with different roles—NAT translates addresses, DHCP assigns IPs automatically, and ARP resolves IPs to MACs on a local network—so they don’t replace classful routing.

CIDR notation expresses an IP address and its subnet mask by appending a slash and the number of network bits after the address (for example, 192.168.0.0/16). The slash-prefixed value shows exactly how many leading bits are the network portion, which lets you define any prefix length rather than sticking to the fixed masks of classful addressing. This flexibility supports more efficient use of IP space and enables route aggregation, reducing the size of routing tables. The idea behind CIDR is to move away from rigid class-based addressing toward flexible prefixes that match actual network needs. The other options describe technologies with different roles—NAT translates addresses, DHCP assigns IPs automatically, and ARP resolves IPs to MACs on a local network—so they don’t replace classful routing.