MSDN Community – Windows Networking

DNS Diagnostics on Windows

Overview

Domain Name System (DNS) is a core component of Windows networking. Proper diagnosis helps resolve name resolution failures, latency issues, and misconfigurations.

Built‑in Tools

  • nslookup – query DNS records.
  • ipconfig /displaydns – view the DNS cache.
  • ipconfig /flushdns – clear the DNS cache.
  • ping – test reachability of a host name.
  • tracert – trace route to a host.
  • Resolve-DnsName (PowerShell) – advanced DNS query.

Interactive DNS Lookup

Enter a hostname to query its A record using DNS-over-HTTPS.

Common Issues & Solutions

  1. Host not found: Verify DNS server settings in Network & Internet > Adapter Options.
  2. Stale cache: Run ipconfig /flushdns and retry.
  3. Incorrect DNS records: Contact your DNS provider or edit the zone in DNS Manager.
  4. Network adapter disabled: Enable the adapter via ncpa.cpl.

Step‑by‑Step Troubleshooting

1. Open Command Prompt (Admin).
2. Run: ipconfig /all
   - Check DNS Servers listed.
3. Test resolution:
   nslookup www.contoso.com
4. If fails, try public DNS:
   nslookup www.contoso.com 8.8.8.8
5. Flush cache if needed:
   ipconfig /flushdns
6. Verify firewall isn’t blocking DNS (port 53).
7. Review Event Viewer > System logs for DNS Client events.

FAQ

Why does nslookup return "Server failure"?
The queried DNS server cannot resolve the request. Check server health or use an alternate DNS.
Can I configure multiple DNS servers?
Yes. In the adapter properties, add secondary DNS addresses. Windows will fall back if the primary fails.
How to configure DNS over HTTPS on Windows 10?
Settings > Network & Internet > Ethernet/Wi‑Fi > DNS settings > Enable "Secure DNS".

Resources