A subnet is a logical division of a network based on what?

• A. IP Address
• B. MAC Address
• C. Hostname
• D. Protocol

Answer: (A)

Subnets are defined by how IP addresses are structured and divided using a subnet mask (or prefix length). The network portion of an IP address, as determined by that mask, determines which devices share the same logical network. Devices with the same network bits can reach each other directly at the IP layer, while traffic to other networks must be routed. That’s why the division of a network into subnets is based on IP addressing.

MAC addresses identify hardware on a local link and don’t define network boundaries. Hostnames are simply human-friendly labels that map to IP addresses, and protocols set the rules for communication rather than how networks are split.