2011-01-20, 04:33 AM
You only tell the one place where you bought your domain from where to point. That DNS registrar will then inform all of the other DNS registrars where your name points to. The delay between the new address being put into effect and the old one lingering (because not all registrars will have all the same information at the same time) is called propogation. Typical propogation is between 24 - 36 hours. Though I have seen some take as fast as 5 - 15 minutes. It all depends on what web traffic is like.