What is the connection between Medium Access Control(MAC) and the hardware MAC address?

Question

For example in an ethernet where all hosts share a common broadcast link for each host to have access to the link there is Medium Access Control like the CSMA/CD protocol.

Also any communications hardware device(Computer NIC, bluetooth adaptor, mobile phone, etc) has a "MAC address". How is this 'MAC address' related to the above mentioned Access Control?

Answer 1

They're not actually related.



The former is a protocol used to detect a carrier on the line, to sense if the line is busy detect collision of data packets. For example, PPP uses CSMA/CD to see when it's okay to send data or how long to wait after detecting a collision before sending more data.



MAC - stands for Media Access Control. It basically refers to your Ethernet card and the MAC address or hardware address or burnt-in address basically refers to the physical address of the card.



MAC addresses are made up of 6 segments of hexadecimal numbers like A1:B2:C3:D4:E5:F6



The first 3 represent the company (every company that makes cards has their own unique number/s)



The last 3 numbers represent the card's own unique number.



That way, as long as the company doesn't make 2 cards with the same last 3 numbers, no 2 cards will ever have the same hardware address.



Unlike IP addresses, MAC addresses are "burnt-in" to the card in the factory and can't be changed (easily).

Answer 2

MAC address is just the address for Media Access Control layer, and it is Media, not Medium. Equate this to an IP address being an address for the Internet Protocol layer. It just defines a device at the layer.

Answer 3

well there is a MAC and you are thinking of the same thing. Mac operates on hardware and software level. It operates on a sub layer of layer 2.