DNS RECORD GUIDE

NAPTR record

Publishes ordered rewrite rules for service discovery.

What is the NAPTR record type?

Name Authority Pointer records describe how a name should be transformed or which SRV service should be queried next.

Common uses

  • SIP and VoIP discovery
  • ENUM telephone routing
  • Complex service discovery chains

What to enter

Enter the domain or ENUM name publishing the NAPTR records.

sip2sip.info

How to read the result

Order and preference control selection; service, flags, replacement and regular-expression fields describe the next action.

How NAPTR DNS lookups work

When a client requests a NAPTR record, it normally asks a recursive DNS resolver. The resolver may return a cached answer or contact the domain’s authoritative nameservers. Cached answers improve speed, but they also explain why a recent DNS change may not appear everywhere at exactly the same time.

DNSReach queries several independent public resolvers and, when possible, the authoritative nameservers for the domain. An authoritative answer reflects the zone currently published by the DNS provider. A recursive answer reflects what that resolver currently knows, which may still be an older cached value until its cache expires.

How to check a NAPTR record with DNSReach

  1. Open the DNS checker and select NAPTR.
  2. Enter sip2sip.info in the format described above.
  3. Run the check and watch each resolver return independently.
  4. Compare public resolver answers with the authoritative results marked by a shield.
  5. Investigate amber results because they differ from the authoritative or majority answer.
Check NAPTR now →

Why NAPTR answers can differ

The most common reason is caching. DNS records have a time to live, and resolvers that cached the previous value can continue serving it until that period ends. Differences can also come from split-horizon DNS, filtering policies, malformed responses, DNSSEC validation failures, resolver outages, or querying a hostname different from the one where the record is actually published.

A failed lookup is not always evidence that the entire domain is broken. “No record” means the requested type was not found at that exact name. A timeout means a resolver did not answer in time, while a refusal means it declined the query. Checking authoritative servers helps distinguish propagation delay from a configuration problem.

Common NAPTR troubleshooting steps

  • Confirm the exact hostname and record type.
  • Check the authoritative answer before changing the zone again.
  • Allow existing cached answers to expire after a change.
  • Verify that every authoritative nameserver publishes the same zone version.
  • Review provider-specific formatting requirements and remove accidental duplicate records.

NAPTR record FAQ

What is the NAPTR record type?

Publishes ordered rewrite rules for service discovery.

How do I check NAPTR records?

Enter sip2sip.info in DNSReach, select NAPTR, and run the check. DNSReach compares public recursive resolvers with available authoritative nameservers.

Why do DNS resolvers show different NAPTR answers?

Resolvers may hold cached data created at different times. A recent DNS change can therefore appear on some resolvers before others until older cached answers expire.

What does “no record” mean for NAPTR?

The resolver answered successfully but found no NAPTR record at the exact name queried. This can be normal when that record type is optional or published at another hostname.

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