Our organization is coming up on changing our IP addresses for our domain. I have been given the task to find out how to quickly push our DNS zones with the new IP information to all the servers including the root servers.

My question is: We are currently using OES 6.5 sp7 and We would like to know of a way to kind of "push" our updated zones to all DNS servers including the root servers, to minimize downtime. I also would like to know of a way to properly clear the DNS cache of our local NS. I have heard the "load named -pa" would be the best bet but, need further opinions. Also, even if I can push our records or not what would the average downtime that the organization would be facing?