I have an internal flat domain with several NetWare 6 (SP3) servers acting
as DNS servers. I want to forward requests to a new domain to an external
DNS server. This I have managed to do using either 'glue records' or a
second domain and using zone-in transfers.

My next problem is, the externally hosted domain has a failover site. I
would like to point my glue record to the primary site, but if/when that DNS
server does not respond, I want to connect to the failover site,
automatically. So hopefully I can point to the primary site all the time
with the glue record, but if that DNS server fails to respond in xx seconds
I can then point to the failover DNS server and site.

Any help would be greatly appreciated.