Flush DNS on Linux: systemd-resolved & more (2026)

Need to flush the DNS cache on Linux? On modern distributions using systemd-resolved, run:

sudo resolvectl flush-caches

Use it after editing /etc/hosts, changing resolvers, or testing a migration when a hostname still resolves to an old IP.

How to flush DNS on Linux

To flush DNS on Linux, run the command for your resolver:

1. systemd-resolved (most distros): sudo resolvectl flush-caches. 2. Older systemd: sudo systemd-resolve --flush-caches. 3. nscd: sudo systemctl restart nscd (or sudo nscd -i hosts). 4. dnsmasq: sudo systemctl restart dnsmasq. 5. Local BIND: sudo rndc flush.

Then verify with resolvectl query myproject.test or dig myproject.test.

Does Linux even cache DNS?

Plain glibc has no DNS cache, so editing /etc/hosts takes effect immediately. A cache exists only when you run a caching layer: systemd-resolved, nscd, dnsmasq, or a local resolver. If unsure which you use:

resolvectl status
systemctl is-active systemd-resolved nscd dnsmasq

When to flush

• You edited /etc/hosts and a tool still resolves the old IP.
• You changed /etc/resolv.conf or your DNS server.
• You moved a staging site to a new server before propagation.

For editing the file itself, see how to edit the hosts file on Linux or the Ubuntu-specific guide.

Verify the result

resolvectl query myproject.test
dig myproject.test
getent hosts myproject.test

getent hosts reflects the full name-service stack, including /etc/hosts.

Troubleshooting

• resolvectl not found: your system may not use systemd-resolved; use the nscd/dnsmasq command instead.
• Still cached in the browser: clear the browser DNS cache and retry in a new tab.
• WSL2: flush on the Windows host too with ipconfig /flushdns.

If you manage many local domains across machines, Locahl keeps hosts entries organized and consistent across Linux, macOS and Windows.

_Last tested: June 2026 on Ubuntu 24.04, Fedora 40 and Debian 12._