Help needed in understanding DNS

[Ben]

Hi,

I am a newbie to BIND. There are a few problems which I encountered and I
would like to know how to troubleshoot and configure a DNS server.

Scenario:
My server is running BIND version 4.9.3. It is configured as a secondary DNS
with the SOA pointing to the Primary DNS host1.domain1.edu.sg and 2 name
server records. 1 of which is the primary DNS and the other is itself.
However, recently, I run into the problem of not able to resolve the DNS
query, e.g host1.domain2.edu.sg. The DNS query data resides in the primary
DNS, but I am able to have a name resolution of www.yahoo.com because of the
cache.dns file.

Q1: Why am I not able to query host1.domain2.edu.sg? I got a name error.

Q2: Is there a way to configure a forwarder, just like the feature in NT
DNS, which will forward the DNS query to primary DNS?

Q3: What are the useful tools that I can use other than debug?

Q4: Any good links on reading the DNS configuration?

Thanks in advance...

Best regards
Benson