Which protocols belong to the TCP/IP Network Layer?

• A. IP, ICMP, ARP
• B. TCP, UDP
• C. HTTP, HTTPS
• D. DNS, TLS

Answer: (A)

In TCP/IP, the Network (Internet) layer is responsible for moving packets between hosts across different networks and for handling addressing and reachability. IP provides logical addressing and routing so packets know where to go. ICMP supports error reporting and diagnostic messages, helping nodes understand issues like a route being unreachable or a packet looping. ARP helps with local delivery by translating an IP address to a hardware MAC address on the local network, so packets can actually be placed on the correct physical medium.

That combination—IP for addressing/routing, ICMP for control messages, and ARP for address resolution on the local segment—fits the Network layer’s role.

The other options belong to different layers. TCP and UDP are Transport layer protocols that manage end-to-end data delivery and reliability. HTTP and HTTPS are Application layer protocols used by web services, with HTTPS adding security via TLS. DNS and TLS are also associated with the Application layer (DNS for name resolution, TLS for securing communications).