Error while connecting two ROS machine to the same MASTER (one is Raspbian jessie, one is Linux in VBox)

edit

HI everyone, I have been trying to learn how to connect two ROS machines to the same master. I am using Linux in Virtual machine (VBox) , and raspbian jessie, and i want the master to run on the linux. what i did was both ROS are kinetic

when i run the linux, i do these steps:

1- hostname -I

i think the first one for the Virtual machine and the second id for the main OS with is MAC OS

 10.0.2.15  10.0.3.1

2-export ROS_IP=10.0.2.15

3-roscore

then i move to the raspbian jessie:

1- hostname -I

 10.0.0.8   2601:1c:8601 ......etc <<very long address with letters and numbers

2-export ROS_MASTER_URI=http://10.0.2.15:11311/

3-export ROS_IP=10.0.0.8

each machine can ping itself, but when i ping the ROS on jessie from linux to seems to work and give me something like

 64 bytes from 10.0.0.8: icmp_seq=0 ttl=63 time=39.868 ms
 64 bytes from 10.0.0.8: icmp_seq=1 ttl=63 time=9.677 ms
 64 bytes from 10.0.0.8: icmp_seq=2 ttl=63 time=38.659 ms

but when i ping the linux from jessie it does not work, it fails.

so does anyone know how to solve that?

*edit 1: when i try to run roscore on jessie it runs with master 10.0.0.8 even though i assigned export

 ROS_MASTER_URI=http://10.0.2.15:11311/

so it looks that it did not get it !?

*edit2: after running netcat i found out that the linux machine can see the raspbian but the raspbian can not see the linux