Layer 2 (Data layer)Switch is an intelligent device, it can be unmanageble(plug and play)or Manageble device which support telnet Uses Mac-adrress table/CAM initially and it either boadcast(flooding) for the first time or unicast request if address is known. Switch only understand mac address and will use ARP when received/send packet to and from Layer 3. Layer 3(Network Layer) support IP and icmp It for Web Policies and Passthrough