Multilayer switching allows a single device to perform both layer 2 switching and layer 3 routing. It uses application-specific integrated circuits (ASICs) to store routing and forwarding information in hardware tables, allowing traffic to be forwarded at line speed with little delay. Multilayer switches can create a switched virtual interface (SVI) for each VLAN to allow routing between VLANs, functioning similarly to a router but with the ports remaining at layer 2. Cisco Express Forwarding (CEF) further improves efficiency by building forwarding tables to store layer 2 and layer 3 information, allowing very fast lookups and transmission of traffic through the switch.