[Understand Routing in Seconds] Now that we have an IP address, is a MAC address still necessary?

I wonder if you are confused: Why do we need a MAC address if we have an IP address?

What is the connection between them? What is the difference? Is one of them redundant?

The rumor reached the ears of "IP address" and "MAC address", and they were also very distressed. Today, I will pass the microphone to them to see what they say?

PART 01, Confession of MAC&IP

MAC address says:

I am a MAC address, working at the data link layer and living on the physical network card.

I am very loyal to my relationship and never change my mind. My "CP" is the same network card all my life. Our relationship is very stable. Each network card has only one unique MAC address, unlike IP addresses which can change with time.

IP address says:

I am an IP address, working at the network layer and living in the IP protocol suite.

Some people say that I am "walking through a field of flowers without getting a single leaf on me" and that I often "team up" with different devices, especially MAC addresses. People often say that I am fickle.

But life is not easy. I only have one "CP" at the same time. The CP combination with this device expired, and before I had time to take a break, I was arranged to "CP" with another device.

Stop, stop, stop! Are you two getting off topic?

Let me introduce it to you!

PART 02. What is MAC address?

MAC address, the full name of which is Media Access Control Address, is literally translated as media access control address, also known as physical address or hardware address.

When each network card leaves the factory, the manufacturer will mark it with a globally unique serial number, just like our ID number.

In other words, the MAC address is not for the device, but for the network card.

Take computers as an example. If there are several network cards on a computer, there will be several MAC addresses. For example, a laptop computer has both wired and wireless networking modes, so there are two network cards, one wired and one wireless, that is, there are two MAC addresses.

PART 03. What is IP address?

IP address, the full name is Internet Protocol Address, which literally means Internet Protocol address.

Mainly used to distinguish different networked devices on the Internet.

The IP address provides a unique logical address identifier for each device connected to the Internet (public network). Through the IP address, we can accurately find the target device on the Internet and establish communication with it. Just like the delivery address filled in when shopping online in real life.

The difference between IP addresses and MAC addresses is that, in order to ensure efficient operation of the network, IP addresses are dynamically assigned and can also be modified manually, just like you can move around or go to a "windy place" to have a look.

But the MAC address cannot be changed at will, just like your ID number. No matter where you move to, the ID number is the most effective proof that "you are you"~

PART 04. What is the difference between IP and MAC?

In fact, there are many differences between MAC addresses and IP addresses. The document has sorted out the differences between MAC addresses and IP addresses so that you can understand them at a glance~

PART 05. Why are both indispensable?

Simply put, the purpose of IP addresses and MAC addresses is to facilitate devices in the network to find each other accurately.

Continuing with the previous example, we compare the MAC address to the ID number and the IP address to the residential address.

If you only have the ID number (MAC address), you will definitely not be able to find your beloved document in the vast crowd.

If you only have the address (IP address), you have found the home of the document owner, but you still cannot tell who is the document owner in the home.

However, if you use the address (IP address) and ID number (MAC address) together, you can first find the province → city → district → street → community, and then use the ID number (MAC address) to easily catch the document owner typing in front of the screen.

Similarly, when devices communicate, IP address and MAC address are also indispensable.

On the Internet, it is rare for both parties to be in the same local area network (LAN). Usually, they need to go through multiple computers and network devices to connect to each other. Because the IP address is unique in a LAN, but in different LANs, the IP address may be the same, and the IP address can be changed manually, which may lead to duplicate IP addresses. However, the MAC address is unique, and the MAC addresses on different devices are completely different, so different LANs rely on MAC addresses to identify different devices to avoid IP address conflicts.

Therefore, "IP address + MAC address" is the real "CP". Only when they are used together can the only device in the network be determined, and data transmission will not go wrong.

PART 06, Test time

How about it? I have learned some useful knowledge with Document Master again today.

Then let’s take a short test to verify the effectiveness of your learning!