What is hierarchical addressing?

• A. A single-level addressing scheme
• B. An addressing scheme made up of several levels, allowing for efficient routing
• C. Addressing that uses MAC addresses
• D. Addressing that requires TCP handshakes

Answer: (B)

Hierarchical addressing is an addressing scheme built from several levels, which allows routers to group addresses into larger blocks and summarize routes for efficient forwarding. In IPv4, this is realized through a network portion plus host portion, and with subnetting and CIDR, networks are organized into multiple layers (major networks, subnets, sub-subnets, and hosts). This structure lets routers look at the higher-level prefix first, apply a broad route, and then refine to the exact sub-network, reducing the size of routing tables and speeding lookups as the network grows. For example, an organization might route all addresses in a big block like 203.0.0.0/16, then break it into smaller blocks such as 203.0.1.0/24 and 203.0.2.0/24, allowing efficient, scalable routing throughout the internet. The other ideas don’t fit because a single-level scheme would be flat and harder to scale, MAC addresses operate at the data-link layer and aren’t about hierarchical routing, and TCP handshakes are about establishing connections, not about how addresses are organized.