What does the network address in an IP address identify?

• A. A host device
• B. A network
• C. The DNS server
• D. The application layer service

Answer: (B)

In IPv4, an address is split into a network portion and a host portion based on the subnet mask. The network address identifies the network segment, not a single device. Routers use the network part to decide where to send a packet next, steering it toward the correct destination network. All devices on the same local network share that network address, while the host portion distinguishes each specific device on that network. The DNS server and application-layer service aren’t identified by the network address itself—the DNS server has its own IP, and the service is identified by ports and protocols—not by the network prefix. Therefore, the network address identifies the network.