What is the role of Network Time Protocol (NTP)?

• A. To synchronize clocks of networked devices
• B. To assign IP addresses
• C. To manage and monitor devices
• D. To access directory services

Answer: (A)

NTP exists to align the clocks of devices across a network so they share a common notion of time. This matters because many network functions rely on accurate timestamps—for example, logs from different devices need to line up to correctly sequence events, security protocols check certificate validity within time windows, and time-based access controls depend on synchronized clocks.

How it works in practice: devices query time servers and exchange timing information to estimate how far off their local clocks are from a reference clock. They then adjust their clocks gradually using a clock discipline algorithm to minimize this offset, even over networks with varying delays. NTP is organized in layers called strata, with highly accurate reference clocks at the top and progressively further-down servers and clients at lower strata. It typically uses UDP port 123 and is designed to handle network latency and jitter while keeping all devices in near-sync.

Other options describe different functions: assigning IP addresses is done by DHCP, managing and monitoring devices is done by network management or SNMP tools, and directory services are provided by LDAP/Active Directory.