title: How could I ping my docker container from my host
body: <p>I have created a ubuntu docker container on my mac</p>
  
  <pre><code>CONTAINER ID  IMAGE   COMMAND      CREATED         STATUS         PORTS                 NAMES
  5d993a622d23  ubuntu  "/bin/bash"  42 minutes ago  Up 42 minutes  0.0.0.0:123-&gt;123/tcp  kickass_ptolemy
  </code></pre>
  
  <p>I set port as 123.</p>
  
  <p>My container IP is <code>172.17.0.2</code></p>
  
  <pre><code>docker inspect 5d993a622d23 | grep IP
  "LinkLocalIPv6Address": "",
              "LinkLocalIPv6PrefixLen": 0,
              "SecondaryIPAddresses": null,
              "SecondaryIPv6Addresses": null,
              "GlobalIPv6Address": "",
              "GlobalIPv6PrefixLen": 0,
              "IPAddress": "172.17.0.2",
              "IPPrefixLen": 16,
              "IPv6Gateway": "",
                      "IPAMConfig": null,
                      "IPAddress": "172.17.0.2",
                      "IPPrefixLen": 16,
                      "IPv6Gateway": "",
                      "GlobalIPv6Address": "",
                      "GlobalIPv6PrefixLen": 0,
  </code></pre>
  
  <p>On my Mac I try to ping my container,</p>
  
  <p><code>Ping 172.17.0.2</code>, I got Request timeout for icmp_seq 0....</p>
  
  <p>What should I do? So my local machine can ping the container I installed. Did I missing some app installation on my container, which is a plain ubuntu system?</p>