rosjava android - phone sends localhost

edit

Hello eveyone!

We installed rosjava and we want to publish and subscribe messages between a PC and an android-phone.

• roscore is running on the PC
  
• there is a publisher and a subscriber on the phone and/or pc
  
• ROS_MASTER_URI is set on the phone to the PC's IP

This works:
- subscribe messages on the phone, which were published on the phone
- subscribe messages on the phone, which were published on the PC
- subscribe messages on the PC, which were published on the PC

This does not work:
- subscribe messages on the PC, which were published on the phone

Our guess:
We think that the phone sends a wrong name ("127.0.0.1") of itself to the core:
- rxgraph shows for the phone-publisher: "ERROR: Communication with node[http://127.0.0.1:55124] failed!
- rxgraph shows for the phone-subscriber: "ERROR: Communication with node[http://127.0.0.1:40919] failed!

-> We already tried to change the phone's name via setprop net.hostname (which changes net.hostname, but does not change the situation at all)
-> We tried to define the name in the phones /etc/hosts file; with no result

What are we doing wrong?