I often find myself struggling with my network configuration. I wonder if there is an easy way or tool to "debug" my routing table by providing an IP address and receiving information about which rule is being applied and why, ideally for Macos or Ubuntu.
The best starting points for this would be the iproute2 man page [1], superuser [2] and serverfault [3]. There are potentially also Linux namespaces to consider. There are some youtube videos that can walk you through the 'ip' command and debugging routes. Start with "debug route linux iproute2" in their search. That's a topic probably too big for HN I think.
[1] - https://manpages.ubuntu.com/manpages/focal/en/man8/ip-route....
[2] - https://superuser.com/
[3] - https://serverfault.com/