PortFast allows small, unmanaged switches to be plugged into ports of access switches without risking switch loops

PortFast disables spanning-tree on the port, which puts the port into the forwarding state immediately after it is connected

Portfast does not generate a spanning-tree topology change when a station on a port is connected or disconnected

PortFast detects one-way communications on the physical port, when prevents switch loops

PortFast prevents switched traffic from traversing suboptimal paths on the network

PortFast prevents switch loops that are caused by a unidirectional point-to-point link condition on Rapid PVST+ and MST