Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2InfrastructureHard
A large enterprise network spans multiple geographical locations, and accurate time synchronization across all devices is critical for log correlation, security forensics, and proper operation of time-sensitive applications. The network architect needs to implement a highly accurate and resilient time synchronization solution that can handle potential failures of primary time sources. Which time synchronization protocol should be deployed, and what specific design consideration ensures resilience?
- ANTP; configuring multiple redundant NTP servers with different stratum levels.
- BPTP; implementing a single master clock for all devices.
- CCDP; relying on router timestamps for local device synchronization.
- DSNTP; using a single, highly accurate stratum 1 server.
Show answer & explanationAnswer & explanation
Correct answer: A. NTP; configuring multiple redundant NTP servers with different stratum levels.
NTP (Network Time Protocol) is the industry standard for highly accurate and resilient time synchronization over IP networks. Configuring multiple redundant NTP servers, ideally with different stratum levels (to account for potential failures of lower stratum servers), ensures high availability and accuracy for critical network operations.
Why the other options are wrong
- B. PTP (Precision Time Protocol) offers even higher accuracy than NTP (sub-microsecond) but is typically used in specialized industrial or financial applications requiring extreme precision, not general enterprise networks. A single master clock also introduces a single point of failure.
- C. CDP (Cisco Discovery Protocol) is used for discovering neighboring Cisco devices and does not provide time synchronization services. Router timestamps are local and not suitable for network-wide synchronization.
- D. SNTP (Simple NTP) is less accurate and does not provide the sophisticated clock synchronization algorithms or resilience of full NTP, and a single server creates a single point of failure.
NTP (Network Time Protocol)
A networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.
- Provides highly accurate time synchronization.
- Uses a hierarchical system of stratum levels.
- Supports redundancy with multiple servers for resilience.
Memory trick: NTP's many clocks keep the network's time always right, even if one breaks.