MAC ADDRESS: Explained
What is a MAC address?
Every network device uses the Media Access Control Address, or MAC, to uniquely identify itself on a network. No two devices, regardless of location, will share the same MAC address.
Every NIC is factory-burned with a 6-byte hexadecimal number, which makes up the MAC address. The MAC address is made up of the alphabets A through F plus any string of numbers.
There are two components to the MAC address. The manufacturer of the NIC, such as Hik Vision, D-Link, Ubiquiti, and so forth, is identified by the first three bytes. The manufacturer’s unique number, which uniquely identifies every device on a network, is contained in the final three bytes.
The MAC address is also known as the physical or hardware address.
There are various formats for MAC addresses. There will be dashes in between the digits on a Windows PC. The digits will be separated by colons on Linux and Apple platforms. Additionally, Cisco will show the MAC address, which consists of four sets of digits divided by periods.
MAC Address vs. IP Address
In order for network devices to communicate with one another, the MAC address is necessary. The MAC address is ultimately used by a device to communicate with another device. And this is true regardless of how close the devices are to one another — for example, they could be on the same network — or how far apart they are — they could be on separate networks.
In summary, MAC addresses are used by devices to communicate with one another. You may be wondering, “Well, if devices communicate with one another via MAC addresses, then of what use is an IP address?” After all, aren’t IP addresses uniquely assigned?
Public IP addresses may be unique but private IP addresses can and do change periodically. Even when your IP address has been the same for a few months, it can be changed by a network administrator or your internet service provider. MAC addresses, however, are static. They last forever.
An IP address and a MAC address are required by TCP/IP, the language used on networks and the Internet, in order for a networking device to operate as intended.
To enable device communication, the MAC address and IP address work together. A device’s MAC address is used to identify the particular device whereas its IP address is used to locate it, on a network.
For instance, a typical neighborhood consists of homes and the people who live there. Every residence has a physical address, and each occupant is identified by a name. An IP address is comparable to a house’s mailing address. We can determine the country, city, and street where the residence is located from the mailing address. However, it doesn’t always reveal the identity of the occupants. However, a MAC address and a person’s name are similar. It identifies the unique occupants of the home.
The location of a networking equipment is disclosed via its IP address. However, a MAC address identifies the device precisely.
How identification and communication works in a LAN
When devices wish to communicate with one another, the MAC address is ultimately required. Picture a local area network, similar to what you would find in a standard house or place of business. Assume for the moment, that computer A wants to communicate with computer B over this local network. Computer A will first check computer B’s IP address to determine whether or not the two are connected to the same network. After the confirmation, computer A now requires computer B’s MAC address in order to communicate.
And it does so by broadcasting an address resolution protocol, or ARP, broadcast. Therefore, it will broadcast to all devices connected to its local network, requesting that machine B provide its MAC address in order to identify itself. Then, communication can begin after computer B provides computer A with its MAC address.
How identification and communication works over a WAN
Consider a WAN scenario, where two devices are on separate networks and wish to communicate with one another?
Suppose the computer A wishes to visit google.com. Computer A need the MAC address of Google’s web server in order to access google.com. However, the issue lies in its ignorance of what it is. That’s why, in order to obtain the MAC address of the web server, it requires the IP address.
After a user types google.com into computer A’s web browser, DNS converts the domain name into an IP address that other computers can understand. After looking at Google’s IP address, computer A will see that it is not part of its local network since it is not part of the same group as its local network.
It will thus transmit this data to the router, which is its default gateway, because it is on a different network. It will let the router handle it, since it’s no longer a LAN but a WAN issue. Thus, machine A will broadcast an ARP request once more, but this time it will request the default gateway’s MAC address.
Machine A will send the data to the default gateway as soon as it has the MAC address. After obtaining the data, the default gateway will examine Google’s IP address to determine the most efficient route for the data to take in order to reach its destination.
The data will be forwarded to the following router:. However, it also requires the MAC address of the subsequent router before it can transmit the data. In order to obtain the MAC address of that router, it will also send out an ARP broadcast. After that, it will send the information on.
Subsequently, the router requires the MAC address of the subsequent router, and so forth. The last router on the data’s path will then require the MAC address of Google’s web server. After that, the data has arrived at its intended destination.
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A hardware device is capable of having more than one MAC address. It just depends on how many network interfaces it has. Three MAC addresses, for example, can be assigned to a computer: one for the wired network adapter, one for wireless, and one for Bluetooth.
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