title: Setting up ehcache replication - what multicast settings do I need?
body: <p>I am trying to set up ehcache replication as documented here: <a href="http://ehcache.sourceforge.net/EhcacheUserGuide.html#id.s22.2" rel="noreferrer">http://ehcache.sourceforge.net/EhcacheUserGuide.html#id.s22.2</a><br>
  This is on a Windows machine but will ultimately run on Solaris in production.</p>
  
  <p>The instructions say to set up a provider as follows:</p>
  
  <pre><code> &lt;cacheManagerPeerProviderFactory
       class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
       properties="peerDiscovery=automatic, multicastGroupAddress=230.0.0.1,
       multicastGroupPort=4446, timeToLive=32"/&gt;
  </code></pre>
  
  <p>And a listener like this:</p>
  
  <pre><code>&lt;cacheManagerPeerListenerFactory
      class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory"
      properties="hostName=localhost, port=40001,
      socketTimeoutMillis=2000"/&gt;
  </code></pre>
  
  <p>My questions are:<br>
  Are the multicast IP address and port arbitrary (I know the address has to live within a specific range but do they have to be specific numbers)?<br>
  Do they need to be set up in some way by our system administrator (I am on an office network)?</p>
  
  <p>I want to test it locally so am running two separate tomcat instances with the above config.
  What do I need to change in each one?  I know both the listeners can't listen on the same port - but what about the provider?<br>
  Also, are the listener ports arbitrary too?</p>
  
  <p>I've tried setting it up as above but in my testing the caches don't appear to be replicated - the value added in one tomcat's cache is not present in the other cache.<br>
  Is there anything I can do to debug this situation (other than packet sniffing)?</p>
  
  <p>Thanks in advance for any help, been tearing my hair out over this one!</p>