VTP, Portfast, Spanning Tree and all the other switch related stuff.
All ports of a hub are in the same collision domain and broadcast domain. Whether the domains expand beyond a connected device depends on the type of device, and in some cases, the configuration of the device.Two hubs connected to separate interfaces of a router would result in two collision domains, and two broadcast domains.Routers separate broadcast domains. In the context of this discussion, when you are talking broadcast domains, you are talking about Layer 2 communication (MAC).The only devices that will receive and process the MAC broadcast are the hosts connected to that hub, and the network interface of the router connected to that hub.
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