DNS Change during transfer

is it possible, will it hurt

[Powdork]

I have a client with several domains that were all pointing to one domain. I am transferring the domains from netsol to 1and1 for her. We have kept the site online that all the other domains point to, but are transferring the other domains without having changed the nameservers first. She now realizes that one of the domains is the target of a magazine ad, but the domain can now be expected to be offline for at least 4 more days (the old hosting account is no longer). I asked the kind folks at 1and1 what the effect of changing the nameservers during the transfer would be and they said it would cause a registration error and screw things up worse. I asked the folks at NetSol, and they said to give it a shot; it might not work but it certainly wouldn't hurt anything.
Who should I believe?

[davezan]

Both. :)

The latter especially said to give it a shot but it might not work. It won't.

The former gave a good reason why it won't work. Thus, registrars have disabled any changes and/or renewals to the domain name to prevent any problems no one wants to have.

[Powdork]

Thanks davezan, that's what I figured.
Doesn't matter though, it's up already. Domain unlocked late Thursday, transfer complete and site up early Monday morning. That's way quicker than 7-10 days.

[davezan]

That's way quicker than 7-10 days.

That's just a worse-case scenario, of course. But good to avoid.

[Powdork]

So how does DNS propagation work. The problem is that I am, and have been able to view the site consistently since Monday morning here in California, but the client in Florida has seen it only briefly. I understand that domain name servers update their databases independently, but there must be some logic to the path in which they are updated. Just as there must be some logic as to the domain name servers that particular machines, browsers or networks consistently request from. What are the factors that influence this?
Physical Location - I am in cali, she is in Florida
ISP - client is with AOL, I am not
Machine, network, or browser cache settings - Mac vs Windows; Safari vs IE vs Firefox
Others factors?

i guess I am most curious over which is more important, location or isp?

[krakrazor]

DNS works in this way...

One server has the main data... Every other server gets the data from that one server... Many of the other servers actually cache the data so new requests do not need to be processed again. So it all depends on how long a sever's cache lasts for. Your client's server on florida probably has yet to renew it's cache. Cache values are usually 24-72 hours

[victor]

The trick is to set the cache time to something short like 1 hour. Then wait 7-10 days for that change to propagate everywhere. Then make the real change. Then reset the cache value.

That way, the unsynced caches exist only for about an hour or so.

At least, in theory....You never know who is going to ignore a cache time of 1 hour and use a longer default value anyway.