We already have IP addresses so why do we need MAC addresses? OK, so I know what youР Р†Р вЂљРІвЂћСћre probably thinking. This is how Cisco display their MAC addresses.Р вЂќР вЂћlthough you likely see the bottom Cisco format when going through the CCNA exam, youР Р†Р вЂљРІвЂћСћll need to be able to look at all three of these and think Р Р†Р вЂљРЎС™That is a MAC address!Р Р†Р вЂљРЎСљ. Lastly, the bottom displays the address as 3 groups of 4 digits. This is how Microsoft display their MAC addresses The middle one is again 6 groups of 2 digits but this time separated by dashes. This is typically how Linux and Apple will display their MAC addresses. The top one is 6 groups of 2 digits separated by colons. Here are three ways to display the same address. ItР Р†Р вЂљРІвЂћСћs important to note, that there is more than one way to show a MAC address and it changes from vendor to vendor. A broadcast address looks like this FF-FF-FF-FF-FF-FF. This will be sent to all device but only those with that application or protocol will listen.Р вЂќР’В«roadcast Р Р†Р вЂљРІР‚Сљ A MAC address that is sent to all devices within a network. Multicast Р Р†Р вЂљРІР‚Сљ A MAC address for an application or protocol. Unicast Р Р†Р вЂљРІР‚Сљ A particular, unique address, that identifies a single network interface card.

The last 24 bits (3 bytes) is a unique value assigned by the vendor. The first 24 bits (3 bytes) is called the organizationally unique identifier or OUI. The first thing to note is that unlike IP addresses, which and can be changed, MAC addresses are unique, and cannot. ItР Р†Р вЂљРІвЂћСћs a unique identifier that is assigned to a network interface card, aka NIC. What is a MAC Address? MAC stands for Media Access Control.

Cisco show mac address