[zamadatix]

What you're describing are drops, which behave differently than collisions. No frame is successfully delivered in a collision while one is during a drop. This project cannot have collisions because the links are full duplex.

Unknown flooding is actually a pretty base requirement of ethernet switches per the 802.1 standard, even when the table is not full, anyways. Without it you can't form switched paths unless every switch in the path has recently heard a broadcast (or following regular flow) from the intended receiver. If you start each test case as a short loved one with an IPv4 client ARPing for neighbors or in a simple topology the this can easily be missed but wreak havoc in the real world. To not do so is as egregious to say you're an ethernet switch which does not flood broadcasts in terms of false claims of being an Ethernet compliant switch.