Introduction
DNS propagation can take a few hours, if not days, to spread. We can force our systems to update DNS records manually, updating our own local cache.
Procedure
Sometimes there is an issue with your DNS resolvers caching the domain name to IP mapping. When you're trying to go to the domain, it's actually pulling up an old IP address instead of looking for a new one and finding the correct record. So, to expedite this very common problem of cached DNS, please do the following steps.
Microsoft Windows Vista and Windows 7
Close your application (e.g. browser or email).
Click the Start orb and follow All Programs > Accessories, look for Command Prompt. Be sure to right click on Command Prompt and choose "Run as Administrator". When the black screen appears, type the following command and hit enter.
ipconfig /flushdns
Restart your application (e.g. browser or email).
Microsoft Windows XP
Close your application (e.g. browser or email).
Go to the Start menu, choose Run, type cmd and hit OK. When the black screen appears, type the following command and hit enter.
ipconfig /flushdns
Restart your application (e.g. browser or email).
Mac OSX
Navigate to your Applications folder, open Utilities, and double click on Terminal. Type the following command and hit enter.
dscacheutil -flushcache
That command should work on Mac OS X 10.5 (Leopard), 10.6 (Snow Leopard) and 10.7 (Lion). If the above command is not available, you can try the other flush DNS command as follows which should work on Mac OS X 10.4 (Tiger):
lookupd -flushcache
Don't worry if either command says something like "Not found".
Restart your application (e.g. browser or email).
Linux
Note: Different distributions and versions of Linux may have slightly different commands due to differences in configuration. One of the commands below will probably work.
Open up a root terminal window (Ctrl+T in Gnome). Type the following command and hit enter.
/etc/init.d/nscd restart
You may need to use sudo depending on your installation instead:
sudo /etc/init.d/nscd restart
Some distributions support this command:
sudo /etc/init.d/dns-clean start
Or support this command:
sudo service nscd restart
Some installations may have NSDS located in another directory, like the following example. You may need to locate where it is installed to be able to execute the correct command.
/etc/rc.d/init.d/nscd restart
Restart your application (e.g. browser or email).