Some applications require that no traffic be forwarded by the Layer 2 protocol between ports on the same switch. In such an environment, there is no exchange of unicast, broadcast, or multicast traffic betweenports on the switch, and traffic between ports on the same switch is forwarded through a Layer 3 device such as a router. To meet this requirement, you can configure ports as protected ports(Set this value to enabled).Protected ports do not forward any traffic to protected ports on the same switch. This means that all traffic passing between protected ports��unicast, broadcast, and multicast��must be forwarded through a Layer 3 device. Protected ports can forward any type of traffic to nonprotected ports, and they forward as usual to all ports on other switches. Dynamically learnt addresses are not retained if the switch is reloaded.