> The TTL is the Time-To-Live of the DNS information from your DNS servers, > it means how long the information remains valid before the DNS server > requesting the info will consider old and request new info. If you drop > your TTL's to like 60 minutes a few days before the move, then name > servers around the net will start to have the 60 min TTL's in cache and > request a new ip within an hour. Essentially, once the move takes place, > you'd only have an hour of time with old ip info around the net. Once the > move is complete, change your TTL back to 24 hours or whatever your > default value is... >
Almost. ttl is information you pass to other dns servers when (and only when) a request is made ttls take time to propagate a ttl is, as you wrote, time to live, but it's meaning is that a server will discard local info after ttl - when ttl is reached there will be no local data - only if a request is made will the local dns server reach out and look for info about the resource dns, except for secondaries, certan round robin configs, and other special situations is a request driven software device - it's possible for a local dns server to think it has good data long long after ttls have been shortened and host info has been changed the strategy is to shorten ttl, hope that new ttl is propagated, and then change host, ptr or other rr and hope enough requests are made so that the new data propagtes you can influence, to the extent other nameservers choose to be influenced, by listing as many nameservers in the 'notify' and 'allow-transfer' sections of 'options' in named.conf (for bind) in short, the propagation is usually request driven and proper data about your resource propagates in direct proportion to requests for it - you can build it and no one may come, or go to the wrong cornfield Pan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Get the mailserver that powers this list at http://www.coolfusion.com FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
