I am just a beginner so what I'll say might be completely out of the truth 

With my university PC, the default IP adress chosen by roscore is 127.0.1.1
(not 127.0.0.1).
I assume this comes from the university network structure.
If I run roscore as such, it outputs the following warning:

WARNING: IP address 127.0.1.1 for local hostname 'pcwin1069' does not appear
to match
any local IP address (127.0.0.1,X.X.26.107). Your ROS nodes may fail to
communicate.

Still, my local processes are able to find the main process. Therefore, I
think the problem comes from your ROS_MASTER_URI variable. 
Are you sure tangm-desktop is the actual name of your computer? (check it
with the command hostname).

Try setting:
 ROS_IP to 127.0.0.1 or nothing
and 
 ROS_MASTER_URI to http://localhost:11311

The ROS install tutorial makes you add the following line to your bashrc
(did you do that?):
(http://www.ros.org/wiki/ROS/Installation/Ubuntu/Deb section 1.5 Environment
setup)
echo "source /opt/ros/boxturtle/setup.sh" >> ~/.bashrc
Check setup.sh: it makes sure your ROS_MASTER_URI variable is properly
initialized.
Note that you might need to replace boxturtle by cturtle is you installed
it.

If that does not work, please post the full outputs of your processes
(including roscore).

Hope it helps

Raph
-- 
View this message in context: http://ros-users.122217.n3.nabble.com/Failed-to-contact-the-master-at-robot-name-11311-tp943764p944300.html
Sent from the ROS-Users mailing list archive at Nabble.com.

------------------------------------------------------------------------------
This SF.net email is sponsored by Sprint
What will you do first with EVO, the first 4G phone?
Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first
_______________________________________________
ros-users mailing list
ros-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/ros-users