The huge volume of requests generated by a system like DNS, the designers wanted to provide a mechanism to reduce the load on individual DNS servers. That's why they devised a way for DNS information to be cached locally. Though, a notable consequence of this distributed and caching architecture, changes to DNS do not always take effect immediately and globally. Thus there are times where you need to flush your DNS cache in order to have updated DNS information.
Below is a step-by-step procedure on how to flush your DNS cache.
For Windows:
1. Click "Start"
2. Choose "Run"
3. Type "command" in the space provided for. Then press "Enter" key.
4. When the command window shows up, type "ipconfig /flushdns" on the command line.
5. Close command window.
For Mac:
1. Go to "Applications"
2. Enter "Utilities" folder.
3. Click "Terminal" icon.
4. Once the terminal window opens, type "sudo lookupd –flushcache"
(for 10.4.X and up the command is "sudo
dscacheutil -flushcache")
5. Close Terminal window.
For Linux:
1. Login or su as root.
2. Execute "/etc/rc.d/init.d/nscd restart"
