Hi,

Just have a quick query, I am in the process of changing hosts for one of my sites that was hosted through another provider. I wish to host it now from my dedicated server.
I was just wondering during the dns propagation time-frame (24-72hrs), I am updating the name servers of the domain by adding to the current ns1 and ns2 name servers the addresses of the new dns name servers
eg. ns3.domain.com & ns4.domain.com

Are you allowed to insert 4 entries into the name server of that domain. I have currently the current dns address that was setup for the old server (ns1.domain.com & ns2.domain.com) and I have added to the name server of the registrar I have the domain through these new values (ns1.domain.com and ns2.domain.com).

So in practice, here is what I have:

ns1.bluehost.com - old dns
ns2.bluehost.com - old dns
ns1.mediatemple.net - new
ns2.mediatemple.net - new

So I guess once the dns propagates all I do is remove the old dns entries
ns1.bluehost.com
ns2.bluehost.com
This should have no downtime for the website.

Is this right in theory and in practice???

If your website is presently accessible according to the DNS entries of both the old and new dns servers, then you CAN do it that way, BUT...

It's much simpler to just take the old dns servers out, replace them with the new ones and not leave the old ones in. Then any place around the world where it has not propagated yet will point to the old DNS servers, anyplace where it HAS propagated will point to the new.

By having all 4 dns servers listed there (which IS allowed), visitors from around the world might end up at the old site or the new site, as it could be querying any of the 4 dns servers. If your site is accessible from both, then it doesn't matter, but still the best practice is to get rid of the old ones and just have the new ones on there.

Keep the sites on the both places for that 72 hours using new NS only

Which is better the better practice to use while updating name servers from an old host to the new host?

ns1.bluehost.com -old
ns2.bluehost.com -old
ns1.mediatemple.net -new
ns2.mediatemple.net -new

OR

ns1.bluehost.com -old
ns2.bluehost.com -old
ns3.mediatemple.net -new
ns4.mediatemple.net -new

If the 2nd way is right then once the domain is pointing to the new name servers ( ns3.mediatemple.net & ns4.mediatemple.net) do you simply change this to

ns1.mediatemple.net
ns2.mediatemple.net

from the old entry ns3 & ns4? if so will this cause the name servers to propagate again for 24-73hrs and the site being down?

You can add the new hosts nameservers, but you'd then end up with your visitors going randomly to the old server, and the new server, even after the propagation of the newly added nameservers is over. So, if you want to change hosts, it doesn't make sense, and it is not a way to avoid downtime in that sense.

You should simply replace the old nameservers with the new ones.

Note: You cannot use "ns1.hostname", "ns2.hostname", "ns3.hostname" etc. just because they make some sort of sense to you. A host's nameservers could very well have the form "mumbojumboa.adomaintheyown.tld", so you must use the nameservers they give you in the welcome email, once you signup.

The correct way is to REMOVE the old nameservers RIGHT AWAY, at the same time you are adding the new ones.

The way to have your site have no downtime, is to host your site in both places, in webservers that are pointed to by both the old and new dns servers. After 72 hours once everyone has propagated, you can take down the old server because everyone is asking the new one.

If your site uses MySQL (or any other database), then using both sites at a time will make your database out-of-sync. Ideally, you should first copy your site to the new server...then REPLACE your old DNS with the new DNS...then put a "Under Construction" page on your old site (NOT on the new site)...and then wait for the new DNS to fully propagate.

However, if you just a non-database site, don't bother to put up a "Under Construction" page on your old site. Hope this helps.