The gateway address (or default gateway) is a router interface connected to the local network that sends packets out of the local network. The gateway has a physical and a logical address. The gateway operates at the network layer (Layer 3) of the OSI Model. The gateway is used when transmitting packets. When packets are sent over a network, the destination IP address is examined. If the destination IP is outside of the network, then the packet goes to the gateway for transmission outside of the network. The gateway is on the same network as end devices. The gateway address must have the same subnet mask as host devices. Each host on the network uses the same gateway.The gateway also operates at the data link layer (Layer 2) of the OSI network model. The physical gateway address is called the media access control(MAC) address or burned in address (BIA). The physical address is assigned when the device is manufactured, and cannot be changed. When a frame is sent to a device not on the local network, the gateway’s MAC address is used in the frame header.