Advice wanted on Nameserver switchover

[Jay Ford]

On Tue, 15 Mar 2011, Stewart Dean wrote:
> Have two questions about the switchover of our external nameservers:
>
> I'll call the old nameservers oldns1, oldns2, offsitens and the new 
> nameservers newns1 and newns2

So, you're replacing oldns1 & oldns2 with newns1 & newns2, while keeping
offsitens.  The master is currently oldns1 & will be newns1.  The others are
slaves.  Yes?

I suggest:
    1. replace oldns2 with newns2
       a. configure newns2 how you want it, pretty much identical to oldns2
          but with different interface addresses; verify things work
       b. disconnect newns2 from the net
       c. change interface addresses of newns2 to those of oldns2
       d. disconnect oldns2 from the net
       e. connect newns2 to the net
       f. verify newns2 working: zone transfers, query resolution...

    2. replace oldns1 with newns1
       a. configure newns1 how you want it, pretty much identical to oldns1
          but with different interface addresses; verify things work
       b. disconnect newns1 from the net
       c. change interface addresses of newns1 to those of oldns1
       d. disconnect oldns1 from the net
       e. connect newns1 to the net
       f. verify newns1 working: zone transfers, query resolution...

    3. verify offsitens still works

No SOA changes, no whois fiddling, back-out 1 box at a time if necessary.

Regarding your idea of pointing whois information at name servers which
aren't live: don't do that.  DNS will probably handle it, but only after
dealing with the fact that 2 of the 5 servers don't work.  You'll see delays
& possibly failures.

________________________________________________________________________
Jay Ford, Network Engineering Group, Information Technology Services
University of Iowa, Iowa City, IA 52242
email: jay-ford at uiowa.edu, phone: 319-335-5555, fax: 319-335-2951