Windows Commands / IT Support Guides
Check DNS answers with nslookup
A website that opens by address but fails by name points toward name resolution. Query the resolver directly before clearing caches or changing DNS settings.
Environment and inputs: Windows 11 · Command Prompt unless PowerShell is specified
Try the diagnostic command
Use the stated shell and platform. Replace sample domains, addresses, services and paths with values from the system you are authorized to support.
nslookup example.com
nslookup -type=MX example.comHow to read the result
The output identifies the answering DNS server and returned records. MX records describe mail routing. A non-authoritative answer is normal when the resolver returns cached or recursive data.
What to do next
Check the exact hostname used by the failing application and compare its answer with the approved internal DNS service. Distinguish a timeout from a name that does not exist.
Before you make a change
Do not send confidential internal hostnames to public DNS servers. Public and private answers may intentionally differ through split DNS.