think you mean 4 nameservers. you can add 4 nameservers
for blah.com at your registrar (check yahoo see how many
each would need to have an A record in the blah.com
zone file. You could select 2 IPs from server1 to be used
as ns1,ns2. You could then select 2 IPs from server2
to be used as ns3,ns4.
you could set up bind on server1 using ns1,2 as
you could set up bind on server2 using ns3,ns4 as
you can add a new account to server1, and this would
use ns1,2 in the new zone file.
ditto for server2, new domain added there would use
This seems OK if you only ever wish to have 2 servers,
but what if you have 11 ?
You may wish to set up additional servers as slave dns
servers. If you're using cpanel etc, you may have to
edit zone files locally on same server as account is set
up, hence this would need to be a slave dns server.
(sometimes the terminology slave nameserver is
used, much confusion can be caused at first).
You could set up a script to transfer all new zone files
etc to a master dns server, and rebuild a new
named.conf, and a complete set of zone files there,
so you wouldn't need tohave bind running on any
additional new servers.