DNS lookup: A, AAAA, MX, TXT, NS and more for a domain
Enter a domain and DuckINT reads its DNS records from Google Public DNS and Cloudflare DNS at the same time: A, AAAA, CNAME, MX, NS, TXT, SOA and CAA. It adds passive DNS history and the hostnames certificates were issued for. To ask for one record type only, type it first, for example "MX example.com".
What it shows
- Current records from two independent resolvers, so a mismatch stands out.
- Mail setup: MX servers and the SPF and DMARC policies in TXT records.
- Passive DNS: addresses the domain pointed to before, with first and last seen dates.
- Hostnames found in Certificate Transparency logs, which often reveal subdomains.
Sources it checks
One search asks all of these at the same time. Each result names the one that returned it.
What to do with the result
- Compare both resolvers: different answers usually mean a recent change that is still spreading.
- Check that the domain has SPF and a DMARC policy; without them its mail is easier to spoof.
- Review subdomains from certificates for services you no longer use and should remove.
Questions
- How do I look up only MX or TXT records?
- Put the record type before the domain, for example "MX example.com" or "TXT example.com"; then only the DNS resolvers run.
- Why do I see old IP addresses?
- Those come from passive DNS, which records what the domain resolved to in the past. Current records are shown separately.
- Is it free?
- Yes, within the Free plan's daily allowance.