code: private void updateExternal(ServerHeartbeat server, String externalId)
    {
      if (externalId != null) { 
        ServerHeartbeat serverExternal = _root.getServer(externalId);
        
        server.setExternalServer(serverExternal);
      }
      else {
        server.setExternalServer(null);
        /*
        if (serverExternal != null) {
          serverExternal.setDelegate(data);
          
          _root.updateSequence();
        }
        */
      }
      
      // data.setExternalId(externalId);
    }
docs: Update the external server delegation.
  
  Cloud static IPs might be routing IPs that aren't local interfaces. In
  that case, the routing assignment to the dynamic IP must be passed along
  with the heartbeat.