Which numeric label uniquely identifies a device using Internet Protocol?

• A. IP address
• B. MAC address
• C. Hostname
• D. Domain name

Answer: (A)

In IP networks, each device is identified by a numeric address that routers use to forward packets. This IP address is the unique identifier that routing protocols and devices rely on to deliver data across different networks. MAC addresses are hardware identifiers tied to a device’s network interface and are used mainly on local links; they’re not used for global routing across the internet. Hostnames and domain names are human-friendly labels that map to IP addresses via DNS, but they aren’t the numeric identifiers that IP itself uses for routing. So the numeric label that uniquely identifies a device for Internet Protocol routing is the IP address.