code: public void activateOptions() {
      try {
        hostname = InetAddress.getLocalHost().getHostName();
      } catch (UnknownHostException uhe) {
        try {
          hostname = InetAddress.getLocalHost().getHostAddress();
        } catch (UnknownHostException uhe2) {
          hostname = "unknown";
        }
      }
  
      //allow system property of application to be primary
      if (application == null) {
        application = System.getProperty(Constants.APPLICATION_KEY);
      } else {
        if (System.getProperty(Constants.APPLICATION_KEY) != null) {
          application = application + "-" + System.getProperty(Constants.APPLICATION_KEY);
        }
      }
  
      if(remoteHost != null) {
        address = getAddressByName(remoteHost);
      } else {
        String err = "The RemoteHost property is required for MulticastAppender named "+ name;
        LogLog.error(err);
        throw new IllegalStateException(err);
      }
  
      if (layout == null) {
          layout = new XMLLayout();
      }
        
      if (advertiseViaMulticastDNS) {
          Map properties = new HashMap();
          properties.put("multicastAddress", remoteHost);
          zeroConf = new ZeroConfSupport(ZONE, port, getName(), properties);
          zeroConf.advertise();
      }
      connect();
      super.activateOptions();
    }
docs: Open the multicast sender for the <b>RemoteHost</b> and <b>Port</b>.