flush DNS Cache in Lion
If you need to flush the DNS cache in Mac OS X, be aware that the commands for this have changed through successive OSs, including Lion.
Flushing the cache is sometimes a good idea if you are unable to reach a site that you know is live but keeps returning an error (you can check whether a site is live for others by typing its address here: Down for everyone or just me?).
Open Terminal (Applications > Utilities > Terminal.app) and use the appropriate command for your operating system:
In Leopard / Snow Leopard
In Lion and Mountain Lion
sudo killall -HUP mDNSResponder
With Lion, you’ll have to follow the command with your Admin password, which will be invisible when you type it.
FastTasks – a utility for ten common terminal tasks
Posted on April 16, 2012, in Mountain Lion, OS X Lion, Snow Leopard and tagged 404 error, dns, down, down for everyone?, dscacheutil, flush, flushcache, host, is my site down, live, lookupd, MAMP, site, test. Bookmark the permalink. 4 Comments.