Let's say we have a single network with no gateway. We have two host (A & B), and one switch. Host A wants to send some good stuff to host B, so if I am correct host A will include its' source MAC address along with the destination MAC address of host B inside of a frame. This frame will go to the switch where it will see the MAC address of host B and will then foward the frame to its' destination. What role, if any, does the IP addresses for these two host have?
IP addressing is a logical address that resides at layer 3 of the OSI model and if I am correct is mainly used when moving about the network and to other networks. Why exactly do we need IP addressing in a local network with no gateway to any other networks? Wouldn't the LAN be able to communicate with just MAC addressing? In a LAN with no gateway, are IP adsresses mainly used for host with an unknown MAC address?