Within the TCP/IP suite, which protocol is specifically designed for transferring files reliably between networked hosts using a client–server model?

Introduction / Context:
File transfer is a fundamental network service. The classic Internet protocol that provides interactive directory listing, file upload/download, and control commands across hosts is the File Transfer Protocol (FTP). It sits above TCP to ensure reliable delivery of control and data streams.

Given Data / Assumptions:

• We need the protocol name, not merely the transport it uses.
• Focus is on standardized client–server file transfer features.
• Other listed protocols serve different purposes in the TCP/IP stack.

Concept / Approach:
FTP uses two TCP connections (control and data) to exchange commands and files. It supports authentication, ASCII/binary modes, and active/passive data channel setup. While HTTP, SFTP, and SCP are modern alternatives, FTP is the canonical protocol explicitly named for file transfer in the TCP/IP suite.

Step-by-Step Solution:
Identify the need: transfer files between hosts.Select the application-layer protocol: FTP.Differentiate from ARP/RARP (address resolution) and TCP (transport only).

Verification / Alternative check:
FTP clients (e.g., command-line ftp) and servers (vsftpd, IIS FTP) exemplify this model. Reliability stems from TCP; the protocol adds the semantics for file operations.

Why Other Options Are Wrong:
RARP/ARP: Map addresses between layers; they do not transfer files.

TCP: Transport protocol; not itself a file transfer application protocol.

None of the above: Incorrect because FTP is precisely designed for this purpose.

Common Pitfalls:
Equating “uses TCP” with being a file-transfer protocol; many applications use TCP, but only FTP provides the file command set.

Final Answer:
FTP