Well, at the moment my network is actually flat :)
This is an experiment I’m doing because I wanted to have all the management stuff on a different subnet (eg. adguard dns is on the “regular” subnet everyone uses, but its web interface is on the special subnet only select devices can talk to).
Of course (like with most stuff in my homelab), it’s not like I really have a super-compelling security reason to that, it’s mostly that I wondered “what if?” :D
Oh. the ping option you are referring to is -I (upper case) and takes either an interface name or an ip. I did try giving a .10/24 IP to the PC and the results were consistent with scenario 1 (pings where source and destination are on the same subnet work, pings acrrss subnets don’t), so I didn’t mention that in the OP