How to Flush DNS

At times you want to force your machine to "forget" (flush) all DNS entries, so that it reloads any recent changes.

This is useful when you've recently updated the ip-address of a domain and want your machine to see the new changes, without relying on any previously stored cache.

Here's how to flush your DNS cache:

Windows

Open a CMD dos box and run:

ipconfig /flushdns

If you get an error about "this requires elevation", do this: Click on the Windows Start button, type "cmd", then right click on the program and select "Run as Administrator"

Mac

In Mac OSX Leopard, you can use the command
dscacheutil to flush the DNS resolver cache:

dscacheutil -flushcache

In Mac OSX versions 10.5.1 and before, the command lookupd -flushcache performed the same task:

lookupd -flushcache

Linux

In Linux, the nscd daemon manages the DNS cache.
To flush the DNS cache, restart the nscd daemon.
To restart the nscd daemon, use the command:

/etc/init.d/nscd restart