04 Try it yourself Interactive
Five nodes, A to E, and four ways to wire them. Pick a topology and step through the same script every time: the wiring, the link count with the formula that produced it, node C dying, and then one cable being cut instead. The stat row counts cables that are still intact with live equipment on both ends, nodes still powered, how many nodes can still reach each other, and how many are cut off from that group. Watch the third number. The same cut is invisible in one topology and fatal in another, and that difference is the whole reason topology is a subject. Nothing plays on its own: Next, Back and Reset, or the arrow keys.