Secondary DNS servers and subdomains

Here at Gustavus we have a lot of subdomains. For example my computer is oachs.it.gac.edu. A little while ago we noticed that our secondary / slave DNS provider could not resolve DNS for any host in any of our subdomains. As it turns out, the solution was to add a couple of lines to our gac.edu.zone file for each subdomain such as this:


it.gac.edu. IN NS cluster-0.gac.edu.
NS cluster-1.gac.edu.


That way the slave DNS server knows to look to our DNS server for the subdomains and not assume that it is authoritative for everything under gac.edu.

Of course the other option was to have our secondary be a slave for all our subdomains too. But in this case that would be too much hassle.