Network Engineering
DNS TTL Reference
Search DNS TTL best practices by record type or scenario. Covers recommended TTL values for A, CNAME, MX, TXT records, pre-change TTL reduction strategies, and negative TTL.
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About this tool
DNS TTL Reference
The DNS TTL Reference covers recommended TTL values by record type, pre-change reduction strategy, negative TTL caching, and cloud DNS provider minimum TTL values.
• Find recommended TTL for an A record before a planned DNS migration
• Determine how far in advance to reduce TTL before a cutover
• Look up negative TTL behavior for NXDOMAIN caching
• Compare TTL minimums across Route53, Cloudflare, and Google Cloud DNS
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FAQ
What does this tool tell you?
The DNS TTL Reference covers recommended TTL values by record type, pre-change reduction strategy, negative TTL caching, and cloud DNS provider minimum TTL values.
What affects the result most?
TTL tradeoffs: low TTL (60-300s) = faster failover, high TTL (86400s) = less DNS queries, better performance. Recommended TTLs by use case: A record 300s (normal), 60s (planned change), CNAME 3600s, MX 3600s, TXT 300s. Pre-change TTL reduction: lower TTL 24-48h before DNS migration — reduces propagation time window.
How should I use the result?
Use this tool to orient quickly to the concepts, field names, or values you are about to look up in a full specification or vendor documentation. It summarizes the common cases; the authoritative source remains whichever standard or vendor doc defines the values themselves.
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