Cisco ENCOR Practice Exam 2025 – All-in-One Comprehensive Guide to Mastering Enterprise Network Core Technologies!

Network Time Protocol (NTP) uses UDP port 123 to synchronize clocks over a network. This protocol is essential for maintaining accurate time across various devices in a network, which is critical for operations that rely on time-stamped data, security protocols, and scheduling tasks.

Choosing port 123 is standardized for NTP, ensuring that devices can communicate time-related information effectively. As such, any device wishing to use NTP must listen for requests and send responses over this designated port. The protocol itself operates in a client-server model, where the client requests time updates from an NTP server, which responds with the current time.

The other options do not pertain to NTP:

- Port 43 is used for WHOIS queries, which provide information about domain name registration.

- Port 80 is the standard port for HTTP traffic, used for web services and websites.

- Port 53 is associated with the Domain Name System (DNS), which translates domain names into IP addresses.

By understanding the specific purpose of port 123 in the context of NTP, you can appreciate the importance of using standardized ports for different protocols to ensure consistent communication across networks.