Cisco Certified Support Technician (CCST) NetworkingIP ServicesMedium
A network administrator is setting up NTP on a router. They configure the router to synchronize its time with a reliable external NTP server. Which of the following is the default UDP port number used by NTP clients to communicate with NTP servers?
- A123
- B53
- C67
- D161
Show answer & explanationAnswer & explanation
Correct answer: A. 123
NTP (Network Time Protocol) uses UDP port 123 for communication between clients and servers. This is a well-known port for time synchronization services.
Why the other options are wrong
- B. UDP port 53 is used by DNS.
- C. UDP port 67 is used by DHCP servers.
- D. UDP port 161 is used by SNMP agents.
NTP Port
The default UDP port number used by Network Time Protocol (NTP) for time synchronization.
- UDP port 123.
- Used by both clients and servers for communication.
- Essential for accurate timekeeping across network devices.
Memory trick: NTP, like a clock, has 123 hands ticking away.