The access layer consists of layer 3 switches, which take routed and switched data packets from the distribution switches and then route them to the access devices in subnets. The access devices in subnets can be modems, video display units, receiver audio phones, IP-based. Access layer switches are primarily deployed in Layer 2 mode in the data center. A Layer 2 access topology provides the following unique capabilities required in the data center: VLAN extension—The Layer 2 access topology provides the flexibility to extend VLANs between switches that are connected. An access switch is a network edge device that directly connects end-user hardware such as computers, IP phones, wireless access points, cameras, and IoT devices to the broader network. The purpose of the access layer is to grant user access to network resources.
