Trace DNS resolution step-by-step from root nameservers to the final answer.
Enter a domain to trace the DNS resolution path from root servers
DNS Trace walks the delegation of a name the way a resolver does, from the VLANlab server: it asks one root server, picked at random, without recursion, then each server the answer refers it to (the servers of the TLD, then of any zone below it, such as co.uk, then the name servers of the domain itself), until one gives the answer, says the name does not exist (NXDOMAIN) or has no record of that type. Each step shows the server asked and its address, the zone it was asked as a server of, what it answered (a referral, the answer, NXDOMAIN, no data or an error) and the time of that one query. A server that does not answer or does not hold the zone is shown, and the next server of the zone is asked. When a referral gives no address (glue) for a server, its address is looked up from the root first. If the walk cannot run, the page says so and shows the answer of the VLANlab resolver instead. Useful for debugging DNS misconfiguration, finding a lame name server, or seeing how DNS works.
On your own computer, dig +trace example.com does the same walk. Linux and macOS have dig; on Windows, use WSL or an older BIND 9.16 build, since nslookup has no trace option. To check a delegation for errors (name servers that do not answer for the domain, a parent zone and a domain that list different name servers, wrong glue), use DNS Health.