Inheritance from globally-set options to zone statements

[Kevin Darcy]

Simon Dodd wrote:

>I'm sorry if this is an obvious question, and it may be more a
>nomenclature problem making my searches fail than anything else.
>
>I'm setting up a BIND9 server, and my named.conf will have the following
>options set:
>
>	options {
>      	  directory "/var/named";
>	        version "8.3.3-REL-NOESW";
>      	  allow-transfer{"none"};
>	        allow-update{"none"};
>	        recursion no;=20
>	};
>
>Am I correct in assuming that because I've set allow-update{"none"} in
>the global options, I won't need to include this in the zone
>information, because inheritance will apply that stricture to each zone?
>
>So in an example zone:
>
>	zone "0.0.127.in-addr.arpa" in{
>		type master;
>		file "localhost.rev";
>		allow-update{none;};
>	};
>
>Is the line allow-update{none;} going to be superfluous because I've
>already declared in the global options that NO zones can be updated?
>
>Sorry to ask obvious questions, but I want to get this right before
>putting in 200-odd zones statements!
>
Yes, there's no point in duplicating in a zone statement what has 
already been set globally.

Also, in the specific case of "allow-update { none; };", there's no 
point in setting that globally either, since it's the default setting. 
(The same does not hold true for "allow-transfer { none; };" or 
"recursion no;", however).

- Kevin