ROS master (roscore) is not running

I am a student studying robot remote control.

On the dashboard, my machines are marked online, but the message “ROS master is not running” continues at the top.
At this time, there is no problem when using ssh, ping 6, but when the slave side executes node, it just stops without an error code.

I want to send the data measured by slave to master.
Help me.

Hi user1.

From what I understand, you have connection via Husarnet between your PC and a robot, and I am assuming roscore is running on the robot while you want to execute the node on a robot.

Did you set the ROS_MASTER_URI parameter on your PC to direct to the Husarnet hostname of your robot?

Best regards.
Krzysztof Wojciechowski.