[Zope] checking DNS resolving?

[Basil Shubin]

Hi friends,

Currently I know one way to monitor DNS server - monitor bind by tcp 
port that has only two state - up or down.

But is there any way to check where is DNS is not only listen on some 
port, but able to resolve queries? I know that check_http can check if 
page accessible for http server and it should be like that, but for DNS 
server.

So there two general question:

1. Is there built-in function for such task or maybe there somewere 
exist ready to use plugin/script?

2. If above is not True! What is general rules for writing addon script? 
  What data I should get and procsess and what data I should return? How 
this data should be formatted (general rules), how I should proccess 
different events and cases, what return code for each of case and so on...

3. Can somebody give me general advices about how I should accomplish 
above task?


Thanks for any advices!