DNS Lookup
Lookup DNS records and compare answers across major public resolvers to verify propagation.
DNS Lookup Usage
What This Tool Does
This DNS Lookup tool queries DNS records and can compare responses across multiple public DNS resolvers to check propagation consistency, TTL behavior, and resolver-specific differences.
How To Use
- Enter a Domain or IP:
- Use a domain for most record types (for example:
example.com). - Use an IP address only for
PTRreverse lookups (for example:8.8.8.8).
- Use a domain for most record types (for example:
- Select a Record Type from the dropdown.
- Choose resolver mode:
- Propagation ON: compares multiple public resolvers.
- Propagation OFF: tests one resolver (system default or your custom resolver IP).
- Optional: enter Custom Resolver IP (like
1.1.1.1) when propagation mode is off. - Click Lookup DNS and review the summary, consolidated records, and resolver table.
Input Fields Explained
- Domain or IP: target host to query. URLs are normalized to hostnames.
- Record Type: DNS record category to query.
- Custom Resolver (optional): DNS server to use for single-resolver checks.
- Check propagation: compares answers from multiple public resolvers to detect differences.
Record Types Explained
A: IPv4 address record (maps hostname to IPv4).AAAA: IPv6 address record (maps hostname to IPv6).CNAME: alias record (points one name to another canonical name).MX: mail exchanger records for email routing.NS: authoritative nameservers for a zone/domain.TXT: text records (SPF, domain verification, policy data, etc.).SOA: start-of-authority metadata (primary NS, serial, refresh/retry/expire values).PTR: reverse DNS mapping from IP address to hostname.SRV: service location record (target host/port for services). Example:_sip._tcp.example.com.CAA: certificate authority authorization (which CAs may issue certs for the domain).
Results Sections Explained
- Successful Resolvers: how many resolvers returned valid answer records.
- Propagation Mismatches: resolvers that differ from majority answer set.
- Unique Records: distinct answers seen after combining all successful resolvers.
- Consolidated Records: merged answer list with TTL and resolver coverage.
- Resolver Responses: per-resolver DNS status and timing details.
Table Columns Explained
- Type / Name / Value: the DNS answer contents.
- TTL (sec): cache lifetime in seconds before refresh is needed.
- Coverage: how many resolvers returned that same record.
- Status: whether resolver returned usable answer data.
- Response Code: DNS response from resolver (for example
NoError,NotExistentDomain,Refused,ServerFailure). - Authoritative: indicates authoritative answer flag from response header.
- Recursive: indicates recursion availability flag from resolver.
- Latency: query round-trip time to that resolver.
- Propagation: whether resolver matches consensus answer set.
How To Interpret Propagation
- All “Matches”: propagation is consistent across tested resolvers.
- Some “Different”: propagation is still in progress or cached records differ.
- No Data on some resolvers: resolver may not have updated cache, record may not exist there yet, or query policy may differ.
- Lower TTL generally means caches should refresh sooner after DNS changes.
Common Response Codes
NoError: query completed without protocol error (answers may still be empty).NotExistentDomain(NXDOMAIN): domain does not exist.Refused: resolver refused the query.ServerFailure: temporary resolver or upstream failure.NotImplemented: operation/type not supported by resolver.
Troubleshooting Tips
- If non-
PTRquery fails, ensure you entered a domain and not an IP. - If
PTRquery fails, ensure input is a valid IPv4/IPv6 address. - For
SRV, include full service label (for example_service._proto.domain.com). - After DNS updates, re-check over time until mismatches disappear.
- If using a custom resolver, verify the resolver IP is reachable and valid.