Provide a tool to diagnose network setup issues

[azeey]

Desired behavior

Many new users run into problems using Gazebo due to improper network configuration. It would be great if we can provide a tool to diagnose the problem. As a first step, we can provide a tool like
https://docs.ros.org/en/rolling/How-To-Guides/Installation-Troubleshooting.html#enable-multicast that checks if there is a UDP multicast problem blocking discovery.

Alternatives considered

n/a

Implementation suggestion

This could be a gz command.

Additional context

Related issues:
gazebosim/gz-sim#1879
gazebosim/gz-sim#2285

[mapi-ng]

Hi @azeey, thank you for bringing this issue.

I have just recently installed ROS2 and Gazebo and I ran into this issue.

I think just having a timeout and an error message with suggestion to enable multicast would be of great help to new users. As a user trying to troubleshoot this kind of issue it would not be my first thought to run a separate gz command for network diagnosis - here is why.

Before I realized that it was sufficient to Enable multicast, I had troubles understanding what the real problem was. My first thought was about graphics driver configuration.

Only after using verbose output with -v 4 debug level did I understand that the issue was rather network related and only then was I able to find this related issue: gazebosim/gz-sim#2285