realtime functions not working across machine boundary

I am using nodejs module within the async drupal distro on a Virtualbox guest server in a "host only" network. i am able to see realtime communications between browsers (users) running on the drupal/node server but can't see the "async" functionality from browsers on either on the host or another guest... Everything else is working ok... all expected pages load... i can send/receive messages between users etc. I'm guessing its a configuration issue but I dont really know where to begin. Any advice appreciated.