Which role does IP serve as a routed protocol?

• A. Provides logical addressing that routers use
• B. Provides error detection for frames
• C. Performs link-layer addressing resolution
• D. Encrypts data in transit

Answer: (A)

IP’s role as a routed protocol is to provide logical addressing that routers use. At the network layer, IP assigns addresses to devices so that each host can be uniquely identified across different networks. Routers look at the destination IP address in each packet and use their routing tables to decide the next hop toward that destination, enabling delivery across multiple interconnected networks. This addressing is logical and independent of the physical hardware on any given network segment, which is why routers can interconnect diverse networks. IP does not handle error detection for frames—that’s the data-link layer’s job (and end-to-end reliability is provided by higher-layer protocols in some cases). It also doesn’t perform link-layer address resolution; that task falls to mechanisms like ARP that map IP addresses to hardware (MAC) addresses on a local network. Encryption isn’t IP’s function either; security and encryption are handled by protocols such as IPsec or TLS.