Modes & associations
02NTP supports client/server, symmetric peer, and broadcast arrangements, with association state appropriate to each.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 2 ↗
RFC 5905 · § 2EXAMPLE
4 / 4
04
Distribute time to listeners.
One-to-many operation has different delay-calibration and security considerations.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
Read the updated RFC section ↗
The packet mode determines the exchange relationship.
- Client mode 3 normally requests a reply from server mode 4.
- Symmetric active and passive modes support peer relationships; broadcast uses one-to-many distribution.
- SNTP uses the compatible exchange with simplified processing and is not intended to replace the full mitigation algorithms everywhere.
Dynamic discovery mechanisms are described in §3.1. Discovering a server is different from authenticating it or establishing that it is a good clock.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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