ROS2 topic command doesn't visualize another machine topics

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I can't see the topics running on other computers. I can only see the topics running on my computer. Topics running on my own computer cannot be seen on other computers. For example: I run "ros2 run demo_nodes_cpp talker" and while my own computer can see the /chatter topic, another computer cannot see this topic.

When I type ros2 multicast send on my own computer and ros2 receive multicast on another computer, the other computer's output is: " Received from <ip_address:port> "hello world". But when I type multicast send on the other computer and receive multicast on my own computer, I get "waiting for UDP multicast datagram .." output. What is the purpose of this situation?

ROS2 distribution = Humble

ROS_LOCALHOST_ONLY=0

ROS_PYTHON_VERSION=3

Ubuntu Version = 22.04