change the SOA

[Aleksander]

Thanks for the replies,

When I register a domain, the registrar requires the nameserver to match 
the SOA's name, that's the reason I have the auto-generated-blah stuff 
in the whois database. I thought the SOA was the record that is the 
first thing queried when resolving to IPs. Guess I was wrong.

About the temp. name servers. The current whois entry lists the 
auto-generated-blah.example.com as the primary nameserver, which is also 
the SOA record's name. I want to get rid of that and have just 
example.com as the nameserver.

If I remove the auto-generated-blah.example.com nameserver entry, things 
will break i presume. Changing the SOA's name on the other hand won't, 
correct? If so, I could start changing the SOA names right away without 
fear that something will break, that so? That way I could have normal 
nameserver entries at the registrar before the IP change.

The ripe entries are the resposibility of the ISP. The PTR zones are at 
the ISP too after all, so is the slave/secondary nameserver. Changing 
the net block only, to get additional public IP's, not changing ISP.

And some general questions:
I've read quite a few DNS and BIND tutorials so far, but still don't 
understand how exatly DNS name resolving takes place. When "local" DNS 
servers don't know anything about a queried domain, say example.com, 
they query the root dns servers. Now how do these know where to search 
for? Do they do whois queries, to get the nameservers? Or do all DNS 
servers perform whois queries? Exatly when are the records for my 
nameservers from the registrar updated? And these are names, not IP's, 
so how does one get the IP address from that? One big question, I feel I 
have missed something important.

The TTL for the domains is set to 5 days at the moment, I should change 
it one week before the IP change to how much? I've seen figures like 15 
minutes and the like, is 15 minutes OK? It's not google.com, so not too 
much extra DNS traffic I guess.

My current plan looks like this:

1.
    a) Change the SOA records.
    b) Add new NS record and leave auto-generated-blah.example.com NS 
intact.
    c) Set TTL to something small, say 15 minutes.
    d) Tell the registrar to change primary NS.

2.
    a) A week later change the A records to new IP's.
    b) Wait 20 minutes to have the slave and anybody else the new A records.
    c) Let the ISP change IPs, PTR, ripe and whatever (this will have to 
negotiated first ofc., but it's still possible).
    d) remove auto-generated-blah.example.com NS record.

The result would be a maximum of an hour downtime due to DNS. Is that 
correct and/or plausible?

Thanks for any tips and answers,
                                 Alex