IP is a protocol that is used on a layer above ethernet. How do IP addresses and MAC addresses work together? There are special MAC addresses, one for example is ff:ff:ff:ff:ff:ff, which is the broadcast address and addresses every network adapter in the network. If the addresses match, the packet is processed, otherwise it is discarded. If a network adapter is receiving a packet, it is comparing the packet’s destination MAC address to the adapter’s own MAC address. Packets that are sent on the ethernet are always coming from a MAC address and sent to a MAC address. Network cards each have a unique MAC address. MAC addresses are the low level basics that make your ethernet based network work. SuperUser contributor Werner Henze offers some insight into the function of the MAC address: This means that 2 24 (= 16.777.216) unique OUAs can be assigned per OUI.Where indeed? What is the specific function of the MAC address? The Answer Bit 25-48 (network adapter identifier): Bits 25 to 48 provide device manufacturers with 24 bits for assigning a unique hardware identifier (organizationally unique address, OUA).A corresponding service is available, for example, on. The assignment of OUIs is usually public and can be determined via databases. Bit 3–24 (manufacturer identification): Bits 3 to 24 encode an identifier (organizationally unique identifier, OUI), which is assigned exclusively to hardware manufacturers by IEEE.

Addresses that are only locally unique are called locally administered address (LAA) and are marked with U/L = 1. If U/L = 0, the address is valid worldwide as a universally administered address (UAA).

Bit 2 (registry): The second bit of the MAC address indicates whether it is an address with global validity (universal) or whether the address has been assigned locally (local).

Multicast addresses are identified by I/G = 1 and are addressed to several receivers. If I/G = 0, it is a unicast address for a single network adapter. This bit is called I/G (short for individual/group). Bit 1 (receiver): The first bit of the MAC address specifies whether it is an individual or group address.The bit sequence of each MAC address is divided into 4 areas, each of which encodes different information.

Mac address stands for