Flushing the DNS Cache on a Mac

Sometimes it can be useful to flush the DNS cache held on your computer. The DNS cache maintains a local cache of mappings between hostnames and ip addresses. So, if either of those change, for example if you change hosting providers, your local DNS cache can get out of date.  The DNS cache will flush itself automatically, but if you need to flush it immediately, open a terminal shell and enter the following:

~ $> dscacheutil -flushcache

This command works on Leopard (10.5) and Snow Leopard (10.6). To flush the cache on Tiger (10.4), open a terminal and execute the following command:

~ $> lookupd -flushcache