Cisco Certified Support Technician (CCST) NetworkingIP ServicesMedium
A network administrator is troubleshooting an application that relies heavily on accurate time synchronization across multiple servers. They suspect that one of the servers is not correctly synchronizing its clock. Which UDP port is commonly used by NTP for time synchronization?
- A161
- B123
- C53
- D23
Show answer & explanationAnswer & explanation
Correct answer: B. 123
NTP (Network Time Protocol) uses UDP port 123 for all its communication, including synchronization requests and responses. Knowing this port is crucial for firewall configurations and troubleshooting time synchronization issues.
Why the other options are wrong
- A. Port 161 is for SNMP agent (UDP).
- C. Port 53 is for DNS (UDP/TCP).
- D. Port 23 is for Telnet (TCP).
NTP Port
NTP (Network Time Protocol) primarily uses UDP port 123 for all its communication, enabling devices to synchronize their clocks with a time server or other network devices.
- Uses UDP port 123.
- Essential for time synchronization.
- Critical for logging, security, and distributed applications.
Memory trick: 123 is as easy as ABC for NTP.