multiple ips per name server

[Paul A]

Hi,
Sort of OT but I have a couple of name servers that we need to move from
another company's network to ours. 
I was thinking of assigning my current name servers another ip address and
changing the name server's ip with netsol to point to this new address,
aliased on eth0:0.
I can't simply change the name servers on the domains as we have thousands
of zones on these name servers and getting all the domain owners to do this
will be a pain.


I'm using bind 9 and I know by default it will listen on all available ips,
I have added a secondary ip to the network card as a test and it works but..

Is this a good way of doing it, will I run into any problems by adding
another address to the nic and having bind answers for 2 name servers?
When I modify the ip address, of the name server that I moving, with netsol
will that ip change across all registrars ?

Is there a better way for me to merge these names severs?

Thanks for your time,
 
Paul