I'm currently trying to establish communication between my Raspberry Pi based robot and a Cluster which are on the same network. Although I am able to ping and SSH one device using the other, I'm still not able to initialise the Raspicam Node(Ubiquiti Robotics node) when roscore is running on the cluster. Also, in the exact opposite circumstances(Roscore running on Raspi) I'm not able to initialise the ORB-SLAM node (ORB-SLAM-ROSNode). The following error shows up in both scenarios:
... logging to /home/pi/.ros/log/721ad8f6-d0dc-11e5-8411-a74b8992ecaa/roslaunch-pi-14554.log Checking log directory for disk usage. This may take awhile. Press Ctrl-C to interrupt Done checking log file disk usage. Usage is <1GB. RLException: Unable to contact my own server at [http://220.127.116.110:36875/]. This usually means that the network is not configured properly. A common cause is that the machine cannot ping itself. Please check for errors by running: `ping` [`18.104.22.1680`](http://22.214.171.1240:36875) For more tips, please see [`http://www.ros.org/wiki/ROS/NetworkSetup`](http://www.ros.org/wiki/ROS/NetworkSetup) The traceback for the exception was written to the log file.
Please take note that the basic talker and listener as mentioned in the suggested link are working perfectly. Is there someone who can tell me what is going on exactly and what's the problem. Also, Is there some other way to transmit images(I'm trying to use FLASK and all but failing since Raspicam sends H.264 codec and OpenCV[VideoCapture() function] is failing to interpret the data). I've heard about LCM(Lightweight Communication and Marshalling) has someone done this before using LCM or is there any resource that can help.
edit 1: All the work was done over an Ethernet-based connection. I experimented by running the simple tutorial. Please take a note that I ran roscore on raspi during the first experiment, and "rqt_graph" and "rosnode list" commands worked perfectly on the cluster. During the second run i ran roscore on the cluster and did the same experiment again by running "rqt_graph" and "rosnode list" on the raspi and I was able to see all the rosnodes during both the experiments. Here is a screenshot of the /.bashrc file.