I got a new sm server to replace one I already have at sm. I want to set up the new server so it can take over the half dozen sites on the old server, then I'll let the old server go. I want the new server set up exactly like the old one except for the new IPs.

The old server is serving dns for the sites on the server. If I use the old dns server name on the new server, then go to godaddy and update the new IPs on the name server, will that work?

Yes, you'll also need to change the NS records in your zone files.

The overlapping period of time that the boxes both claim simultaneously to be ns1 and ns2.s3pro.com, albiet with different IP numbers, that won't be a problem?

No, because the root dns servers will point to one or the other. As long as the only change between the two is the NS records everything should be fine.

Great. How about this. What if I go ahead and setup the old domains on the new server, with the new ips. Then I setup a _new_ name server on the new server and get it plugged in at godaddy.

Then, I edit the zone files on the new server, and put the old ips from the old server in them.

Then I edit all my domains at godaddy and point them to the new name server.

During the few days of propagation for the new name server to get around, I think some http and mail requests would go to the old name server, and some would go to the new name server, right? But all requests would still wind up at the same, old web server, because all my name servers on both sm servers point to the same, old ips.

Then, after the dns settles down, I edit my zone files on the new name server and point those domain names away from the old server and toward the new server.

Would this give me instantaneous switchover to the new server, bypassing the problems with propagation making request detinations temporarily uncertain?

That would not give an *instantaneous* switchover, but that would certainly lessen the problems you may face.

One thing you are missing, is that several days before you switch your DNS to the new IP addresses, you would want to bring the TTL on your zones down to a couple of hours. That will give you the best performance.

ttl? That means 'time to live'? Right now it is 86400. I assume that is seconds, which is 24 hours. As in that info is subject to getting cached somewhere for up to 24 hours? This somewhere is some kind of regional server near the requester?

How low can I go on that time? Like one hour? Less?

Updating that requires normal propagation time to get the new ttls out?

Thanks.

I see my name server is 24 hours and the individual domains are 4 hours. Do they both need to be lowered?

As long as your zones are lowered to a couple of hours, this should have them expire off of other people's servers in a reasonable time so that they refresh with the new zone.

Thanks a lot, that TTL tip was the best information I've lucked into in a while. Working great, giving me super control in tests.