Which protocol is primarily used for pushing/sending electronic mail from a mail client to a mail server or between mail servers?
SMTP is a push protocol running over TCP port 25 (or submission port 587) used to send email from clients to servers and transfer email between MTAs.
What is the key advantage of IMAP4 over POP3 for email retrieval?
POP3 downloads emails and typically deletes them from the server, making multi-device access messy. IMAP keeps emails on the server, synchronizing state (read/unread, folders) across all devices.
What standard default port is used by Secure Shell (SSH) for encrypted remote terminal access?
SSH uses TCP port 22 to provide secure encrypted remote login and command execution, replacing unencrypted Telnet (port 23).
Which of the following is a primary security flaw of the Telnet protocol?
Telnet operates on TCP port 23 and transmits all keystrokes, credentials, and text in unencrypted plaintext, making it vulnerable to packet sniffing.
Which cryptographic algorithm is an asymmetric (public-key) algorithm?
AES, DES, and 3DES are symmetric-key algorithms. RSA is a common asymmetric algorithm, but it is not listed; therefore, None of the above is correct.