Unable to contact my own server

asked 2020-06-20 05:04:55 -0500

Giri gravatar image

updated 2020-06-20 08:01:00 -0500

gvdhoorn gravatar image

Hi, I git coned a repository from https://github.com/ros-industrial/uni.... when I tried to roslaunch the U5 robotic arm I got the following error:

Unable to contact my own server at [http://user-devil:45261/].
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 user-devil

For more tips, please see


The traceback for the exception was written to the log file
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This error is not caused by the packages in the repository you've cloned.

It's a generic ROS error drawing attention to the fact that you've misconfigured your system.

Either your hostname isn't user-devil, you've hard-coded ROS_MASTER_URI to use that name, or you have a very strict firewall blocking all connections.

gvdhoorn gravatar image gvdhoorn  ( 2020-06-20 08:02:13 -0500 )edit

So what can be done to fix this

Giri gravatar image Giri  ( 2020-06-21 01:50:13 -0500 )edit

Review the values you have set for ROS_MASTER_URI, ROS_IP and/or ROS_HOSTNAME.

Also: does a ping user-devil work?

gvdhoorn gravatar image gvdhoorn  ( 2020-06-21 03:59:00 -0500 )edit