Flush local dns cache on browser and system

Browser(application) level:

For Google Chrome/Chromium, open the link below:
and click “Clear host cache

For Firefox, open the link below:
and click “I’ll be careful, I promise!“,
and find network.dnsCacheExpiration, set its value to 0 (create one if it didn’t exist).
Now the cache should be flushed, and set network.dnsCacheExpiration back to 3600, or you the cache will not work at all.

Operating system level:

ipconfig /flushdns

Depends on the dns service:
sudo /etc/init.d/dns-clean restart
sudo /etc/init.d/nscd restart
sudo /etc/init.d/dnsmasq restart
/etc/init.d/named restart

Mac OS X(after 10.5):
dscacheutil -flushcache