MYTHOSKnow which question DNS answers
DNS translates a requested name into records. It does not prove that a website is honest, that a service is reachable or that the computer hosting it is secure. A troubleshooting note should include the queried name, record type and resolver used. Saying DNS works without that context can hide the actual problem.
This exercise performs read-only queries. Use an example domain or your own service, and avoid sharing internal names in public screenshots.
Compare the answers deliberately
- Open Command Prompt or PowerShell and query the hostname with the computer's current resolver. Note the server and returned answer, including any aliases.
- Repeat the query for the record type relevant to the problem. An A record concerns IPv4; an AAAA record concerns IPv6. A mail-routing investigation commonly needs MX records instead.
- If your network policy permits it, compare with a known public resolver. Private internal names may not resolve publicly; that can be expected rather than an error.
- Check the authoritative DNS settings for a domain you manage before editing anything. A response from a recursive resolver can reflect cached data or a different DNS view.
nslookup example.com
nslookup -type=AAAA example.com
nslookup -type=MX example.comVerify the relevant service separately
After obtaining an expected answer, test the actual application through its normal client. A correct IP address does not establish that the web server, certificate, firewall or authentication is working. Keep the DNS observation separate from the service observation in your notes.
When comparing answers, consider caching, deliberately different geographic responses and private network names. Different answers are a starting point for investigation, not automatic evidence of poisoning.
Avoid destructive troubleshooting
Do not replace organisation DNS settings with a public resolver just because one query fails. That can break internal name resolution and management policy. Similarly, flushing a cache does not fix an incorrect authoritative record; it only changes what is consulted next.
Save a useful result
Record the time, resolver, name and record type, with sensitive values sanitised. If changing an authoritative record becomes necessary, export or record its previous value and understand its purpose first. One precise query result is more actionable than a screenshot containing dozens of unrelated network settings.
Official references
Consult the current vendor documentation if your version or screen differs.
Documentation-based draft. Commands have not all been executed against the named products in a lab. Validate configuration examples against your installed version before changing a working system.