title: How do I get host networking to work with docker swarm mode
body: <p>From <a href="https://github.com/moby/moby/pull/32981#issuecomment-300883830" rel="noreferrer">this PR</a> that got recently merged into docker's 17.06 release candidate, we now have support for host networking with swarm services. However, trying out a very similar command I'm seeing an error:</p>
  
  <pre><code>$ docker service create --name nginx-host --network host nginx                                                              
  Error response from daemon: could not find the corresponding predefined swarm network: network host not found
  </code></pre>
  
  <p>I'm running the 17.06 release candidate:</p>
  
  <pre><code>$ docker version
  Client:
   Version:      17.06.0-ce-rc2
   API version:  1.30
   Go version:   go1.8.3
   Git commit:   402dd4a
   Built:        Wed Jun  7 10:07:14 2017
   OS/Arch:      linux/amd64
  
  Server:
   Version:      17.06.0-ce-rc2
   API version:  1.30 (minimum version 1.12)
   Go version:   go1.8.3
   Git commit:   402dd4a
   Built:        Wed Jun  7 10:06:06 2017
   OS/Arch:      linux/amd64
   Experimental: true
  </code></pre>
  
  <p>What's different from my command from what docker now supports?</p>