The OUI is typically right at the front of the address.įor example, consider a network adapter with the MAC address “00-14-22-01-23-45.” The OUI for the manufacture of this router is the first three octets: 00-14-22. These manufacturers all place a special number sequence (called the Organizationally Unique Identifier or OUI) in the MAC address that identifies them as the manufacturer. Some well-known manufacturers of network adapters or NICs are Dell, Belkin, Nortel, and Cisco. Meanwhile, a hacker who’s hijacked a network IP address will be blocked because their MAC address will not be on the approved list and will be filtered out. This way, computers whose MAC addresses are approved will be able to communicate through the network - even if they were given a new IP address by the Dynamic Host Configuration Protocol (DHCP) process. In MAC address filtering, the router is configured to accept traffic only from specific MAC addresses. On wireless networks, a process called MAC filtering is a security measure to prevent unwanted network access by hackers and intruders. For a network administrator, that makes a MAC address a more reliable way to identify senders and receivers of data on the network. MAC addresses are useful for network diagnosis because they never change, as opposed to a dynamic IP address, which can change from time to time. MAC addresses are very useful in diagnosing network issues such as problems with IP addresses. What is a MAC address used for?Īll devices on the same network subnet have different MAC addresses. Think of the ARP as a passport that takes data from an IP address through an actual piece of computer hardware. Something called the Address Resolution Protocol (ARP) translates an IP address into a MAC address. It is hardwired or hard-coded onto your computer’s NIC and is unique to it. Manufacturers assign a MAC address to a network adapter when it is produced. Whereas IP addresses are associated with a networking software called TCP/IP, MAC addresses are linked to the hardware of network adapters. A NIC turns data into an electrical signal that can be transmitted over the network.Įvery NIC has a hardware address that’s known as a MAC address. The NIC is essentially a computer circuit card that makes it possible for your computer to connect to a network. It’s tied to a key connection device in your computer called the network interface card, or NIC. What is a MAC Address?Ī Media Access Control (MAC) address is a string of characters that identifies a device on a network. In the end, to get the data you want right to YOU, it comes down to addresses - specifically, IP addresses and MAC addresses. Whether you work in a wired network office or a wireless one, one thing is common for both environments: It takes network software and hardware (cables, routers, etc.) to transfer data from your computer to another, or from a computer thousands of miles away to yours.

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