title: How to connect to Docker API from another machine?
body: <p>I'm trying to use the Docker API to connect to docker daemon from another machine. I am able to do this command successfully:</p>
  
  <pre><code>docker -H=tcp://127.0.0.1:4243 images
  </code></pre>
  
  <p>But NOT when I use the real IP address:</p>
  
  <pre><code>docker -H=tcp://192.168.2.123:4243 images
  2013/08/04 01:35:53 dial tcp 192.168.2.123:4243: connection refused
  </code></pre>
  
  <p>Why can't I connect when using a non-local IP?</p>
  
  <p>I'm using a Vagrant VM with the following in Vagrantfile: <code>config.vm.network :private_network, ip: "192.168.2.123"</code></p>
  
  <p>The following is iptables:</p>
  
  <pre><code># Generated by iptables-save v1.4.12 on Sun Aug  4 01:24:46 2013
  *filter
  :INPUT ACCEPT [1974:252013]
  :FORWARD ACCEPT [0:0]
  :OUTPUT ACCEPT [1511:932565]
  -A INPUT -p tcp -m tcp --dport 4243 -j ACCEPT
  COMMIT
  # Completed on Sun Aug  4 01:24:46 2013
  # Generated by iptables-save v1.4.12 on Sun Aug  4 01:24:46 2013
  *nat
  :PREROUTING ACCEPT [118:8562]
  :INPUT ACCEPT [91:6204]
  :OUTPUT ACCEPT [102:7211]
  :POSTROUTING ACCEPT [102:7211]
  :DOCKER - [0:0]
  -A PREROUTING -m addrtype --dst-type LOCAL -j DOCKER
  -A OUTPUT ! -d 127.0.0.0/8 -m addrtype --dst-type LOCAL -j DOCKER
  -A POSTROUTING -s 172.16.42.0/24 ! -d 172.16.42.0/24 -j MASQUERADE
  </code></pre>