NAPTR Record Lookup Tool

Check NAPTR records instantly across global resolvers to validate your advanced URI and telecom routing rules.

How to troubleshoot VoIP and SIP routing with a NAPTR Lookup

NAPTR records are complex DNS records primarily used in Internet Telephony (VoIP) and ENUM (E.164 Number Mapping) to translate phone numbers and services into internet addresses. Enter your domain (or reversed ENUM domain) above to query its active NAPTR rules and verify your telecom routing.

Interpreting your NAPTR results

  • Order and Preference: Like MX records, NAPTR records use numbers to determine priority. The Order dictates the absolute processing order (lowest first). If multiple records have the same Order, the Preference dictates the tie-breaker.
  • Flags (S, A, U, P): Look closely at the flags in the result. A "U" flag means the next step is a URI. An "S" or "A" flag means the next step is querying an SRV or A/AAAA record.
  • Services & Regex: The Services field tells the client what protocol is available (e.g., SIP+D2U for SIP over UDP). The Regular Expression (Regex) field is where the actual translation (like turning a phone number into a SIP URI) happens.

Related tools

SRV record validator TXT record check tool A record lookup