In the process of sending a Telnet message from application to the network, which sequence is correct?

• A. The IP header is added, the TCP header is added, the Ethernet header is added, the Telnet-formatted data is provided to the next layer.
• B. The Telnet-formatted data is provided to the next layer; the IP header is added; the Ethernet header is added; the TCP header is added.
• C. The Telnet-formatted data is provided to the next layer; the TCP header is added; the IP header is added; the Ethernet header is added.
• D. The Telnet-formatted data is provided to the next layer; the Ethernet header is added; the IP header is added; the TCP header is added.

Answer: (C)

The essential idea is how data is encapsulated as it moves down the protocol stack, with each layer adding its own header. Telnet runs over TCP, so the Telnet payload first becomes a TCP segment by attaching a TCP header at the transport layer. Then that segment is wrapped by the Internet layer with an IP header, forming an IP packet. Finally, the data-link layer adds the Ethernet header to create a frame that can be placed on a local network medium. Therefore, the correct sequence is: Telnet data is passed to the next layer, then the TCP header is added, then the IP header is added, and finally the Ethernet header is added. This order ensures each layer’s header corresponds to the appropriate encapsulation stage for proper delivery and interpretation.