DNS propagation refers to the time it takes for changes in the Domain Name System to be recognized across the global network of DNS resolvers. Understanding propagation timelines is critical for minimizing downtime and ensuring smooth transitions.
1. Name Server Updates (Delegation Changes)
When you change the name servers for a domain, you are updating the delegation information stored at the parent zone (the TLD registry, such as .com or .ca). This affects where all DNS queries for your domain are directed.
Where the change occurs: Parent zone (TLD level).
TTL influence: NS records at the parent zone typically have TTLs of 24–48 hours.
Propagation behavior:
Registries update their zones quickly (often within minutes).
Recursive resolvers cache delegation data until TTL expires.
Expected timeline:
Partial propagation: Within a few hours.
Full global propagation: 24–48 hours.
2. Individual DNS Record Updates
When you modify an A, MX, TXT, or other record inside your zone, the change happens on your authoritative name servers.
Where the change occurs: Authoritative DNS servers for your domain.
TTL influence: The record’s own TTL (commonly 300 seconds to 86,400 seconds).
Propagation behavior:
Authoritative servers serve the new record immediately.
Recursive resolvers continue using cached data until TTL expires.
Expected timeline:
Immediate effect: On authoritative servers.
Global propagation: Usually minutes to a few hours, depending on TTL.
3. Newly Registered Domains
When you register a new domain, the registrar sends the delegation info to the registry, which publishes it in the TLD zone.
Where the change occurs: Parent zone and root servers.
Propagation behavior:
Registry updates are near-instant.
Root and TLD zones refresh frequently (often every 15–60 minutes).
Negative caching (NXDOMAIN) can delay visibility for up to 30 minutes or more.
Expected timeline:
Starts resolving: Within minutes to an hour.
Full global visibility: Up to 24 hours, rarely 48 hours.
Quick Reference Table
Change Type | Scope | Typical TTL | Full Propagation |
Name Server Update | Entire domain | 24–48 hrs | 24–48 hrs |
DNS Record Update | Single record | 5 min–24 hrs | Minutes–24 hrs |
New Domain Registration | Entire domain | N/A | Minutes–24 hrs |
Best Practices to Minimize Downtime
Lower TTLs before making DNS record changes (e.g., set to 300 seconds a day in advance).
Ensure new name servers are fully configured and serving the correct zone before updating delegation.
Use monitoring tools to verify propagation status globally.
Avoid making changes during peak traffic periods.