On Sun, Jun 3, 2012 at 12:12 PM, Alex Bravo <robotatlas@gmail.com> wrote:
> I ran into an issue while doing "Understanding ROS Nodes"
> tutorial http://www.ros.org/wiki/ROS/Tutorials/UnderstandingTopics#preview
>
> I noticed that killed ROS nodes are not being removed from "rosnode list".
>
> When I used "rosnode info turtlesim", I saw:
> ...
> contacting node http://i7:56977/ ...
> ERROR: Communication with node[http://i7:56977/] failed!
>
> I thought maybe it was because I did not have $ROS_HOSTNAME defined as
> described here:
> http://www.ros.org/wiki/ROS/NetworkSetup#Single_machine_configuration
> So I added export ROS_HOSTNAME=localhost
>
> After that "rosnode info turtlesim" give me:
> ...
> contacting node http://localhost:60372/ ...
> Pid: 6178
>
> I thought it was strange to see a different port number, but rosnode list
> started working.
>
> Then I went to the next tutorial and did "roscore" while other roscore was
> running.
>
> Then I noticed that  "rosnode list" again doesn't work and "rosnode info
> turtlesim" now gives:
> contacting node http://localhost:39889/ ...
> ERROR: Communication with node[http://localhost:39889/] failed!
>
>
> P.S. I'm using Fuerte with a fresh Ubuntu-12.04, 64-bit.

Alex,

This is a good question for answers.ros.org.

Please see: http://www.ros.org/wiki/Support
-- 
 joq