The emergence of multi-port hubs has enabled Ethernet networks to be configured in a star topology where the hub acts as a network concentrator for connecting multiple devices. This is the most common topology for new Ethernet installations. The hub and its attached devices and segments may comprise the entire Ethernet network, as would be typical in a small office environment, or the hub may be linked to another hub or switch.

Two computers can be directly connected without a hub via a specially wired unshielded twisted pair (UTP) cable referred to as a crossover cable.

Three or more devices can share an n-port hub where n is typically chosen to exceed the initial number of devices to allow for network expansion.

In the network below, Client11 can be configured to share its printer with the other networked computers. Computers that share resources are referred to as hosts, or peer servers.

Hubs can be cascaded to support network expansion or reduce cabling on a physically disperse network.

In the preceding network only one client can transmit data at a time, a logical structure referred to as a collision domain. As the number of devices increases clients have to wait longer to transmit and network throughput decreases as the result of data collisions. Network performance can be increased by adding an Ethernet switch, a device that creates a separate collision domain for each port.

In the figure below each hub operates in its own collision domain and up to three Clients, one in each domain, can transmit simultaneously. The figure also illustrates how routing capability can be added to a switch to enable network clients to share an Internet connection.