In carrier networks, Layer 3 switches may be used at metro edge nodes, enterprise leased-line access points, and service aggregation positions. You can configure a port as a Layer 2 interface or a Layer 3 interface. A routed interface is a physical port that. Layer 3 switches provide the routing function, which indicates a network-layer function in the OSI model. This example uses router configurations of AR3600 V200R007C00SPCc00. The access layer plays a critical role in connecting end devices—such as computers, printers, IP phones, and wireless access points—to the rest of the enterprise.