ROS2 Foxy: Nodes can't find each other if a new device is added to network after starting node

edit

Hello everyone,

we have a ROS2 network with multiple computers. What we do is the following: Start multiple ROS2 nodes on PC1. Once they are running we add a second computer (PC2) to the network. If we do so we can't see any topic on PC2. Then we restart all nodes on PC1 while PC2 is still connected to the network. If we do so, suddenly we can see all topics on PC2. Why is it not possible to see the topics right away after connecting it to the network? In our application it's not possible to restart all nodes on PC1 after connecting PC2 to the network.

Kind regards, Jeremy