Hack the Route Start free Open app Switches and VLANs
Broadcast storm
A broadcast copied round a loop of switches for ever, because Ethernet frames have no hop limit.
Each switch floods every copy it receives, so a single broadcast in a loop never dies, and every new broadcast adds to it until the links and the switches' CPUs are full. Frames from one device arrive from two directions, so switches keep moving its MAC address between ports (MAC flapping) and send unicast traffic the wrong way. Storm control caps the broadcasts per port and second, which limits the damage; only spanning tree, blocking a port, removes the loop.