CyberCertPrepNetwork FundamentalsCommon Protocols & PortsEASYFree question
What is the 'Registered Ports' range according to IANA and give two examples of well-known services in this range?
- A.Registered ports: 49152-65535; examples: SSH (22) and HTTPS (443); POP3 downloads mail over TCP 143 and leaves a synchronized copy on the server
- B.Registered ports: 1024-32767; examples: SMTP (25) and DNS (53); HTTP/3 runs over TCP 80 because QUIC requires TCP's congestion control underneath
- C.Registered ports: 0-1023; examples: HTTP (80) and FTP (21)
- D.Registered ports: 1024-49151; examples: MySQL database (TCP 3306) and Microsoft RDP (TCP 3389)
Why D is correct
IANA port ranges: Well-Known Ports: 0-1023 (require root/admin privileges to bind on Linux/Unix). Registered Ports: 1024-49151 (registered by IANA for specific services/applications; no privilege required to bind). Dynamic/Ephemeral Ports: 49152-65535 (OS uses for client-side ephemeral ports). Examples of registered ports: MySQL 3306, RDP 3389, VNC 5900, SIP 5060, Minecraft 25565, Docker 2376, ZooKeeper 2181, MongoDB 27017, Redis 6379. One option describes Well-Known ports range. Another option describes Dynamic/Ephemeral ports. A third option has an incorrect upper bound (32767) for Registered ports.
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