title: What does "oui Unknown" means in tcpdump?
body: <p>Please refer to example packet:</p>
  
  <pre><code>    2010-08-22 21:35:26.571793 00:50:56:9c:69:38 (oui Unknown) &gt; Broadcast, 
      ethertype Unknown (0xcafe), length 74
      0x0000:  0200 000a ffff 0000 ffff 0c00 3c00 0000  ............&lt;...
      0x0010:  0000 0000 0100 0080 3e9e 2900 0000 0000  ........&gt;.).....
      0x0020:  0000 0000 ffff ffff ad00 996b 0600 0050  ...........k...P
      0x0030:  569c 6938 0000 0000 8e07 0000            V.i8........
  </code></pre>