Examkin

Question

Difficulty: MediumNetworking Ports and Protocols

A network technician is auditing network security documentation to verify default port filtering rules on an enterprise gateway. Match each networking protocol to its correct default port number and transport layer protocol.

  • Telnet (Teletype Network)TCP 23
  • POP3S (Post Office Protocol 3 Secure)TCP 995
  • NTP (Network Time Protocol)UDP 123
  • HTTPS (Hypertext Transfer Protocol Secure)TCP 443

Answer

Telnet matches with TCP 23, POP3S matches with TCP 995, NTP matches with UDP 123, and HTTPS matches with TCP 443.
Each protocol correctly pairs with its standardized port and transport layer assignment: Telnet requires TCP 23 for unencrypted remote command line sessions, POP3S uses TCP 995 for secure email retrieval, NTP uses UDP 123 for network clock synchronization, and HTTPS relies on TCP 443 for encrypted web browsing.

Step-by-Step Solution

1
Determine the default port and transport protocol for unencrypted terminal connectivity (Telnet).
Telnet operates on TCP port 23.
Legacy remote terminal management relies on connection-oriented TCP traffic on port 23.
2
Determine the default port for secure email retrieval (POP3S).
POP3S operates on TCP port 995.
While unencrypted POP3 uses TCP port 110, encrypted POP3S uses TCP port 995.
3
Determine the transport protocol and port for time synchronization (NTP).
NTP operates on UDP port 123.
Clock synchronization requires fast, low-overhead datagram transmission over UDP port 123.
4
Determine the default port for encrypted web communications (HTTPS).
HTTPS operates on TCP port 443.
Secure web traffic over SSL/TLS uses TCP port 443, unlike unencrypted HTTP on port 80.

Key Concept

Standard TCP/UDP Port Numbers and Protocols
Estimated Time:1m 30s
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Topics

Networking Ports and Protocols

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