title: powerdns responding to queries dig . NS @yournameserver
body: <p>I was told about security problem with responding to following queries:
  dig . NS @yournameserver
  I can't find if it affects my powerdns version 2.9.22-3 and how to prevent responding to that query.</p>
  
  <p>My DNS server respond to above queries with:</p>
  
  <pre><code>; &lt;&lt;&gt;&gt; DiG 9.7.3-P3 &lt;&lt;&gt;&gt; . NS @XX.XX.XX.XX
  ;; global options: +cmd
  ;; Got answer:
  ;; -&gt;&gt;HEADER&lt;&lt;- opcode: QUERY, status: NOERROR, id: 49208
  ;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 13
  ;; WARNING: recursion requested but not available
  
  ;; QUESTION SECTION:
  ;.              IN  NS
  
  ;; ANSWER SECTION:
  .           3600    IN  NS  A.ROOT-SERVERS.NET.
  .           3600    IN  NS  B.ROOT-SERVERS.NET.
  .           3600    IN  NS  F.ROOT-SERVERS.NET.
  .           3600    IN  NS  G.ROOT-SERVERS.NET.
  .           3600    IN  NS  E.ROOT-SERVERS.NET.
  .           3600    IN  NS  C.ROOT-SERVERS.NET.
  .           3600    IN  NS  D.ROOT-SERVERS.NET.
  .           3600    IN  NS  J.ROOT-SERVERS.NET.
  .           3600    IN  NS  K.ROOT-SERVERS.NET.
  .           3600    IN  NS  L.ROOT-SERVERS.NET.
  .           3600    IN  NS  I.ROOT-SERVERS.NET.
  .           3600    IN  NS  H.ROOT-SERVERS.NET.
  .           3600    IN  NS  M.ROOT-SERVERS.NET.
  
  ;; ADDITIONAL SECTION:
  H.ROOT-SERVERS.NET. 3600    IN  A   128.63.2.53
  B.ROOT-SERVERS.NET. 3600    IN  A   128.9.0.107
  A.ROOT-SERVERS.NET. 3600    IN  A   198.41.0.4
  K.ROOT-SERVERS.NET. 3600    IN  A   193.0.14.129
  G.ROOT-SERVERS.NET. 3600    IN  A   192.112.36.4
  F.ROOT-SERVERS.NET. 3600    IN  A   192.5.5.241
  D.ROOT-SERVERS.NET. 3600    IN  A   128.8.10.90
  J.ROOT-SERVERS.NET. 3600    IN  A   198.41.0.10
  I.ROOT-SERVERS.NET. 3600    IN  A   192.36.148.17
  L.ROOT-SERVERS.NET. 3600    IN  A   198.32.64.12
  C.ROOT-SERVERS.NET. 3600    IN  A   192.33.4.12
  E.ROOT-SERVERS.NET. 3600    IN  A   192.203.230.10
  M.ROOT-SERVERS.NET. 3600    IN  A   202.12.27.33
  
  ;; Query time: 62 msec
  ;; SERVER: XX.XX.XX.XX#53(XX.XX.XX.XX)
  ;; WHEN: Wed Nov 23 12:58:44 2011
  ;; MSG SIZE  rcvd: 449
  </code></pre>