title: Docker Network Namespace
body: <p>I'm using docker ubuntu:quantal</p>
  
  <p>It seems that network namespaces is not enabled. How can I enable network namespaces?</p>
  
  <p>root@e5e9957daa67:~# ip netns add blue</p>
  
  <p>Failed to create a new network namespace: Operation not permitted</p>