How does subnetting increase the ammount of broadcast domains?
* Short answer: Each subnet is really a different IP network, and each IP network contains its own broadcast domain, as layer-2 broadcasts don’t go beyond the local interface (port) of a router. * Details and comments: It’s not really the fact of subnetting that increases the amount of broadcast domains in a given group of computers, but using different IP networks and making sure each network is physically (or somehow) separated from the others, that is, either connecting computers (that belong to different networks) to different switches or using VLANs. A broadcast domain refers to the area of a network where layer-2 broadcasts are propagated, that is, Ethernet frames with a destination address of FF-FF-FF-FF-FF-FF. Consider that if you subnet a given network, but still leave all computers connected to the same switch, they will all still be in the same layer-2 broadcast domain. That’s why besides subnetting (or simply using different classful network addresses) you will also need to
