ROS2: communication over two machines on the same network

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Can you please! provide all steps you have followed. Thanks

I am not sure what do you mean with all the steps I have followed. I publish a topic with ros2 topic pub /topicXYZ msg_type (e.g. ros2 topic pub /asdfg nav_msgs/msg/Path) and on the other machine I use ros2 topic echo /topicXYZ (e.g. ros2 topic echo /asdfg)

I was telling you about configuration steps, Do you have /topicXYZ msg file in other machines? If no then I would suggest to add the following msg file and build a package and try.

That message type is installed in both machines

Main Pc:

export ROS_MASTER_URI=http://url:11311/
export ROS_HOSTNAME=192.168.1.1
export ROS_IP=192.168.1.1

Second Pc:

export ROS_MASTER_URI=http://192.168.1.1:11311/    # Ip address of 1 PC
export ROS_HOSTNAME=192.168.1.2
export ROS_IP=192.168.1.2

This was my configuration while connecting 2 PC.

You have to include this in your bashrc file.

Thank you for your support and time but the problem was the firewall, sudo ufw disable solved the issue

make it an answer and tick it.

ROS2 does not use any of those environment variables to connect.