DNS - some important questions

Hello

I'm running my own DNS server, but I will have to move to another server with other IP's within two days.

What is the best way to minimize downtime?
1. register 2 new NS's with my registrar pointing to the new IP's and let the old 2 NS working for about a week?

2. updating the existing NS's pointing to the new IP's and updating all DNS entries to point to the new NS's?

3. something else?

important question:
I have registred a new NS some weeks ago, however, when I try to ping this NS, it doesn't resolve.
- it this because my DNS server has no entry for this new NS? I don't know the reason.

Thanks
Genius

"I have registred a new NS some weeks ago, however, when I try to ping this NS, it doesn't resolve.
- it this because my DNS server has no entry for this new NS? I don't know the reason."

There's all kinds of reasons why it may not resolve, but if you don't have an entry for the new NS in your old NS's zone file then you need to correct that.

As for migration, it appears you know what to do. Check the old name servers logs to be sure it has stopped accepting queries before you take it down. If it's still recieving traffic find out why.