How to Flush DNS in Different operating Systems

The role of the Domain Name Server is to translate URLs and FQDNs into their corresponding IP Addresses and allow you to route traffic to and from the target machines (whether it be a local network or over the internet). In case of DNS poisoning or just an incorrectly cached address mapping, you can "flush" the DNS to get a new list of name resolution.

To flush DNS cache in Microsoft Windows
 - open up command prompt and type in:
 ipconfig /flushdns

To flush the DNS cache in Linux, restart the nscd daemon
 - issue the following command:
 /etc/rc.d/init.d/nscd restart

To flush the DNS cache in Mac OS X Leopard:
 - open up terminal and issue the following command:
 lookupd -flushcache

To flush the DNS cache in Mac OS X
 - open up terminal and issue the following command:
 dscacheutil -flushcache