Wildcard behaviour

[Howard Wilkinson]

I have been asked about the behaviour of the MyDNS product when 
answering questions that match wildcards. I am looking for a 
(definitive) answer as to the behaviour of BIND in this case.
The particular case I have is that the server has a wildcard A record 
for a zone (e.g *.example.com -> 192.168.1.1) and the query is for a 
host with a label that contains a dot (e.g. www.us.example.com)

Should the server match the wildcard if:

   1. The label is in the example.com zone?
   2. The label is in a delegated zone which is also served by this server?
   3. The label is in a delegated zone which is served by another server
      and we are supporting recursion?
   4. The query is for a different type of record?

With item 4 this becomes complicated if we are looking for MX records etc.

What would BIND's behaviour be in these cases, are there any other 
subtle things to worry about and what behaviour is likely to kill 
resolvers/clients if we get it wrong.

Regards, Howard.
-- 

Howard Wilkinson

	

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