Requests for any and all undefined subdomains of a given
valid domain result in NXDOMAIN errors, and are identical
regardless of query type.
- They are limited by <span><strong class="command">nxdomain-per-second</strong></span>
+ They are limited by <span><strong class="command">nxdomains-per-second</strong></span>
(default base <span><strong class="command">responses-per-second</strong></span>).
This controls some attacks using random names, but
can be relaxed or turned off (set to 0)