How Many Bits are in a MAC Address

The internet is really a brilliant and innovative thing when you think about it. The fact that we can share data with others, access online content from anywhere in the world, and do all of it wirelessly shows us just how amazing technology can be. As one would expect, the internet and the hardware used to get online all have settings and have “addresses” that are used to communicate with each other, much like homes have their own addresses used to identify them. While many people are familiar with IP addresses – or rather, the unique address that identifies online devices including computers, laptops, and tablets – you may or may not be familiar with a MAC address, what it is, how it works, and the specifics of this identifier.

What is a MAC Address?

Just like an IP address identifies your connected device and allows it to communicate with other devices while connected to the internet, the MAC address is similar in that it is used as an identifier. However, there are some very distinct differences.

MAC stands for Media Access Control. It is a set of numbers that identifies network devices. This number is set by the manufacturer and is embedded within the hardware so it cannot be altered. It is also known as a fixed address for this reason. While it was once known as an Ethernet address, other types of hardware have been introduced making this term more obsolete. Wi-Fi and Bluetooth are among the technologies that also use MAC addresses.

Your MAC address can be access through your operating system by using commands. Like IP addresses, MAC addresses are all unique. However, they all follow the same set of rules when it comes to format.

How Many Bits Are in a MAC Address?

Traditionally, MAC addresses are made up of 12-digit numbers and are made up of 48 bits, or 8 bytes. However, some types of hardware require a 64-bit MAC address. Certain wireless home automation systems, for example, may require a 64-bit MAC address.

When using an IPv6 network, the settings change a bit more. These networks translate 48-bit networks to 64-bit networks by inserting an FFFE value in the middle. These identifiers are used to differentiate between 48-bit addresses and 64-bit addresses.

What Are Typical Formats for MAC Addresses?

As mentioned, there are a few different formats that are used for MAC addresses, depending upon the network and specific hardware. Traditionally, these addresses are written in the format of MM:MM:MM:SS:SS:SS. However, this can vary. Two additional formats for 48-bit addresses are MM-MM-MM-SS-SS-SS or MMM.MMM.SSS.SSS.

A 48-bit address that is converted to a 64-bit address would be formatted as MM:MM:MM:FF:FE:SS:SS:SS.

What Do These Numbers Mean?

You may be wondering what these numbers mean. The answer is simpler than you may think. The first six digits, which makes up 24 bits in a 48-bit network, is a prefix that is used to identify the manufacturer of the device. It’s not unusual to find that several devices created by the same manufacturer have different prefixes, however. This is because some of the biggest manufacturers utilize multiple prefixes across their lines of products.

The next set of numbers, which makes up the remaining 24 bits, is essentially a serial number. This identifies the particular device. All products from the same manufacturer that have the same prefix (or first set of digits) will have a distinct second set of numbers. Each will be unique. However, if the prefix is different, the product identifier may be the same, even when the products are from the same manufacturer. You may also find that the identifier is the same between two products from different manufacturers. However, as already explained, each manufacturer has its own prefix, so this number will vary. In short, every device will in some way have a completely unique MAC address, whether they were made by the same manufacturer or not.

Will I Ever Need to Change My MAC Address?

In general, you will not find any cause for changing your MAC address. This is simply a number that identifies the network device that you are using, and there shouldn’t be any reason to change it. However, some internet users may encounter issues with their ISPs when they change equipment, such as upgrading their router or obtaining a new residential gateway. The ISP has essentially linked the MAC address of the old equipment to the network. When this equipment changes, so does the MAC address, leaving a customer unable to access the internet.

This is when MAC address cloning comes into play. When his happens, the ISP links the new hardware to the old MAC address so that connectivity is maintained. If the equipment is being sent over directly by the ISP, the cloning process has most likely already been performed so you will experience no interruptions. If, however, you are choosing to update your own equipment, a quick call to your ISP can help clear up any service issues caused by MAC addresses that do not match. This may include providing you with troubleshooting steps to change your router or equipment settings.

However, other than these instances, your MAC address is fixed and will not need to be changed.

Final Thoughts

As you have read, your MAC address is used to identify each piece of networking hardware. With so many devices going online, it’s critical that every user and device is identified, which is why these addresses are so important. Now, when you see your MAC address, you’ll know exactly what it’s for, how many bits makes up each address, the proper format, and what those numbers mean. If you have any questions about MAC addresses or have any helpful tips to offer, leave a comment below!


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