Hortonworks sandbox has IP 127.0.0.1 with hadoop services running internally on different ports.
Mapping of services to ip 127.0.0.1 can be found as below-
1. Open Sandbox
2. Go to Settings -> Network -> Port Forwarding
3. You can see list of ports mapped to IP.
Below is reference screenshot -
Let me know if i get your question correctly. Will be happy to help you further.