312-50V10 · Question #74
Identify the UDP port that Network Time Protocol (NTP) uses as its primary means of communication?
The correct answer is A. 123. NTP uses UDP port 123 as its standard communication port for synchronizing clocks between network devices.
Question
Identify the UDP port that Network Time Protocol (NTP) uses as its primary means of communication?
Options
- A123
- B161
- C69
- D113
How the community answered
(28 responses)- A89% (25)
- C7% (2)
- D4% (1)
Why each option
NTP uses UDP port 123 as its standard communication port for synchronizing clocks between network devices.
Network Time Protocol (NTP) is assigned UDP port 123 by IANA and uses it as the primary transport for all time synchronization messages between NTP clients and servers. UDP is used because time synchronization requires low overhead and NTP handles its own reliability mechanisms, making the connectionless UDP protocol appropriate.
UDP port 161 is assigned to Simple Network Management Protocol (SNMP), used for network device monitoring and management, not time synchronization.
UDP port 69 is assigned to Trivial File Transfer Protocol (TFTP), used for simple file transfers without authentication, not time synchronization.
TCP port 113 is assigned to the Ident (Authentication) protocol, used to identify the user of a TCP connection, not time synchronization.
Concept tested: NTP protocol UDP port number assignment
Source: https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml
Topics
Community Discussion
No community discussion yet for this question.