Mark.Andrews@isc.org writes: > Whenever you have a parent and child zones under different administrative > controls it is impossible to change both zones simultaniously. False. Set the clocks correctly, and schedule the change on all the servers for a particular time, using (for example) the tinydns timestamp feature described in http://cr.yp.to/djbdns/tinydns-data.html. When that time rolls around, all the servers will change their data simultaneously, as RFC 1034 requires. Yes, this is difficult to achieve with BIND, AXFR, etc. But it's easy to achieve with better software, better replication protocols, etc. You're making a fool of yourself when you call it ``impossible.'' ---D. J. Bernstein, Associate Professor, Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago