DNS concept about recursive query

[Jay zh]

Dear:

    I have a question about DNS recursive query. For example, xyz-domain.com 
has two dns servers which are www.xyz-domain.com and dns.xyz-domain.com. In 
the root server, these two servers also have glue records.

    www.xyz-domain.com. IN A 1.1.1.1
    dns.xyz-domain.com. IN A 2.2.2.2

    Now both 1.1.1.1 and 2.2.2.2 are not available. If someone use my dns 
server to do recursive query and want to get the A record of 
www.xyz-domain.com and this result is not in the cache, can it get the A 
record? Someone said that it can get the answer because root server has the 
A record and the resolver got this then stopped doing query. I found some 
dns server's behavior is like this, but I test it in my dns ( bind 8 and 9) 
and  I can't get this behavior. Which option should I set?

    If I am not wrong, I know that resolver should stop doing recursive 
query after asking authoritative dns server and get a response from it if 
this answer is not in the local cache. In this case, both of the 
authoritative dns servers are unreachable and the dns server will response 
timeout, is it true?

  Thanks a lot.

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