Pete Freitag Pete Freitag

Working with /etc/hosts on Mac

Published on December 01, 2008
By Pete Freitag

Creating hosts file entries allows you to create DNS aliases which can be very handy for web development. If your on a Mac, you will notice that it has the /etc/hosts file just like other unix os's.

One problem I kept running into however was that OS X was caching my host entries. So if I added a line like this:

And then I changed it to this:

The host will still resolve to the old IP address.

Flushing the DNS Cache on Mac

If you are running Mac OSX Leopard (10.5) or greater, you use the dscacheutil command to flush the dns cache, eg:

dscacheutil -flushcache

If you are using an earlier version of Mac OSX, for example 10.4, then you need to use the lookupd command:

lookupd -flushcache

mac apple osx dns cache

Working with /etc/hosts on Mac was first published on December 01, 2008.

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Great tip. Except that even with a dscacheutil refresh and a reboot I'm still seeing sites blocked because of the hosts file, after it'd been edited to not block anything. Not sure what to do...
by Larry on 10/01/2009 at 1:48:00 PM UTC