TL;DR: How to flush the DNS cache and test name resolution

KB ID 2610140005

Problem: You changed a DNS record (or someone did) and a computer still resolves the old address, or a name that should work does not, and you want to clear the local cache and test name resolution properly.
Applies to: Windows DNS Client (ipconfig, DnsClient PowerShell module, nslookup), macOS mDNSResponder, systemd-resolved (resolvectl), nscd, dnsmasq, unbound
Time to fix: 5 to 10 minutes

Symptoms, platforms, difficulty and more

Symptoms: ping or a browser reaches the old IP address after a record was changed. "Could not find host", "server can't find name" or "Non-existent domain" for a name that exists. nslookup or dig give the right answer but the application still gets the wrong one. Works on one machine and not another.
Platforms affected: Windows 10, Windows 11, Windows Server, macOS, Linux (systemd-resolved, with notes for nscd, dnsmasq and unbound)
Difficulty: Beginner (command line)
Verified on: Linux part run on Omarchy (Arch Linux), systemd 261, 14 October 2026, read-only: resolvectl status, resolvectl statistics, resolvectl query example.com (answer shown as "Data from: cache"), resolvectl –cache=no query example.com (answer shown as "Data from: network"), getent hosts and getent ahosts, reading /etc/nsswitch.conf, and the resolvectl man page. resolvectl flush-caches was deliberately not run. The Windows and macOS parts were not tested; they were checked against Microsoft Learn and Apple documentation. The nscd, dnsmasq and unbound notes were checked against their manual pages, not run. dig was not installed on the test machine, so the dig lines were not run.
Category: How-to
Updated: 14 Oct 2026
Tags: DNS, Linux, macOS, Networking, Windows

The fix only. No explanation, no diagnosis. Read the full article if any of this does not match what you are seeing.

Check what it resolves now: Resolve-DnsName www.example.com (Windows), getent hosts www.example.com or dig www.example.com (Linux, macOS).
Windows, elevated prompt: ipconfig /flushdns (or Clear-DnsClientCache in PowerShell).
macOS, administrator account:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Linux with systemd-resolved: sudo resolvectl flush-caches. Many Linux systems have no cache, so there is nothing to flush.
Compare with the server itself: Resolve-DnsName www.example.com -Server 8.8.8.8 or dig @8.8.8.8 www.example.com.

If the server returns the wrong answer, flushing the client changes nothing. Fix the record or the server.

Also check the hosts file and the browser's secure DNS (DNS over HTTPS) setting.

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Updated on October 14, 2026