What’s the MAC address?

MAC address is used to distinguish the node on datalink layer.

So what’s the differences from IP address?

Table of contents

Number of digits

Firstly, the number of digits is different from IP address.

Although IP address has 32 digits(IPv4) or 128 digits(IPv6), MAC address has 48 digits which is usually expressed by hexadecimal.

These 32 digits is divided into 4 part.

①1st digit⇒ unicast address(0) or multicast address(1)

②2nd digit⇒ universal address(0) or local address(1)

③1st to 24th digit⇒ vender identification code called as OUI

④25th to 48th digit⇒ network interface controller(NIC) specific

MAC address is written on the EEPROM chip of the Ethernet Card.

When system boot, system read the MAC address from this Chip and write the same address on Address Setting Register in Network Control Chip.

We can find the MAC address by myself.

On the command prompt, when you type “ipconfig /all” and hit enter, you can see the Physical Address which is MAC address.