Security and Performance issues

ACL for quiries and recursive lookups to prevent spoofing and DoS attacks against DNS server:

acl our-nets { 192.168.5.0/24; };
acl bogusnets {109.18.3.0/24; };

options {
            ...
    
     allow-query { our-nets; };
     allow-recursion { our-nets; };
     blackhole { bogusnets; };
};

The ACL also can be set for individual zones:

zone "this.com" {
  type master;
  file "this.com";
  allow-query { any; };
};

Not CPU intensive with static zones. May be CPU intensive with dynamicaly updated zones.

Memory consuming as it is desirable to fit all cache and zones into RAM.

Set maximum allowed cache size, for example 50 MB:

max-cache-size 50000000;

Limit the number of simultaneous recursive clients:

recursive-clients 500

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