Comprehensive and Detailed Step-by-Step Explanation:To answer this question, we need to identify the port numbers associated with email protocols used in client-server communication.
* Port 25 (SMTP - Simple Mail Transfer Protocol):
* This port is primarily used for sending emails between mail servers and from mail clients to mail servers (sending outbound mail).
* SMTP is an essential protocol for email traffic.
Reference: CompTIA A+ Core 1 Exam Objectives (220-1101), Domain 2.5 - Explain basic wired and wireless networking concepts, including ports and protocols.
Port 110 (POP3 - Post Office Protocol v3):
POP3 is used for retrieving emails from a mail server. It is commonly used for downloading email messages to a local client, after which the messages are deleted from the server.
While not as commonly used today (due to IMAP being preferred), POP3 is still a recognized email protocol, and its association with port 110 makes it a valid answer.
Reference: CompTIA A+ Core 1 Exam Objectives (220-1101), Domain 2.5 - Explain basic wired and wireless networking concepts, including ports and protocols.
Incorrect Options:
A: Port 23: This is the Telnet protocol used for remote terminal access. It is not related to email traffic.
C: Port 67: This port is associated with the DHCP (Dynamic Host Configuration Protocol) server-to-client communications. It is unrelated to email.
E: Port 137: This port is part of NetBIOS, used for name resolution in legacy Windows environments. It is not relevant to email traffic.
F: Port 443: This port is used for HTTPS (secure web traffic) and is unrelated to email protocols.
Key Takeaway:The two correct port numbers associated with email traffic are B. 25 (SMTP) for sending emails and D. 110 (POP3) for retrieving emails.