What port number does NTP use?

Network Time Protocol (NTP) uses port number 123 for communication. This protocol is essential for synchronizing clocks of computer systems over packet-switched, variable-latency data networks. Using UDP (User Datagram Protocol) for its transport, NTP service is vital in environments where accurate timekeeping is crucial, such as in servers, network devices, and distributed systems.

Ports 80 and 443 are commonly associated with web traffic—port 80 for HTTP (HyperText Transfer Protocol) and port 443 for HTTPS (HTTP Secure). These protocols are not used for time synchronization. Similarly, port 25 is primarily used for SMTP (Simple Mail Transfer Protocol), which handles email transmission. Understanding the specific port assignments helps in configuring firewalls, troubleshooting network issues, and securing services effectively.