Why does my MAC address change on its own?

The MAC address is unique and unchanging. Network card for each computer.

MAC address on .

It is unique in the world and theoretically immutable. Because it was burned on the network card by the manufacturer when it left the factory. In fact, not only the network card has a MAC address, but also many network devices.

They all have their own MAC addresses as well.

Introduction:

LAN Address, MAC address, Ethernet.

An ethernet address or physical address is an address used to identify the location of a network device.

in the OSI model.

, the third layer of the network.

Responsible for IP addresses.

The second layer of data link is responsible for MAC addresses. If a device has one or more NICs, each NIC needs to have a unique MAC address.

The MAC address modified by the individual is just a disguised MAC address, because the MAC address is the computer ID number in the hardware at the factory time, there is no harm in changing the MAC address, but the duplication of other people's MAC will cause network conflicts, just change one, to restore the factory address just need to set it to "non-existent" in the network settings to restore the default, the steps are as follows:

Materials required: computer, win764-bit example.

First, right-click "Network", and then click "Properties".

2. Then click "Local Connection".

3. Click "Properties" in the local connection.

Fourth, then click "Configure".

5. Click "Advanced" in the new window that opens.

6. Finally, click "Network Address", check "Does not exist" on the right, and click "OK" to restore the factory MAC address.

Yes, it can be set. The steps are as follows.

1. Open the Windows 7 system, enter the main interface, click the network option in the lower right corner, and click Open. 2

2. Then, select "Open Network & Sharing Center" from the options and click Open.

3. Select "Change Adapter" settings on the left side of the window and click Open.

4. Select the network in the window and click Open.

5. Click on the "Configure" option in the dialog box and click Open.

6. Finally, modify the MAC address of the computer in the [Network Address] location to solve the problem.

Let's put it this way: there is no possibility of running out, MAC address is the address used by the link layer to the network layer, used to identify a host in the same broadcast domain (LAN), a broadcast domain is the range of all interfaces of a switch, out of this range is that the IP address and MAC address have no half-dime relationship, the largest switch I have not seen more than 100 interfaces, but MAC addresses have 2 48, the possibility of conflict is too small. If the network equipment manufacturer can guarantee that the device with the same MAC address will not be manufactured within 10 years, then there is no possibility of conflict between the root and the disadvantages.

LAN: Several hosts (possibly computers and routers) can be connected to a switch or hub, and when a host wants to send data, a piece of data is formed"MAC address - IP address - destination host port - data"In the form of common Ethernet, the channel you use to send data (such as network cable, wifi) is shared by multiple hosts (there is a bit of a difference when using network cable to connect to the switch, but in essence it is still a shared medium), all hosts will receive data sent by others (ARP spoofing implementation basis), other hosts will confirm whether this data is sent to themselves through the MAC address, ordinary terminal hosts (such as mobile phones, If the router receives this data, if it does not go to the path to the destination IP address in its own routing table, it will be discarded, if there is, the MAC address will be stripped and the MAC address of the destination router interface on the next hop network segment will be added, and the next router will be sent to the next router in the same way until it reaches the destination host, so the MAC address will only take effect when the next host is selected, and it will become invalid after reaching the interface of the next host.

Nowadays, we use optical fiber to connect to the Internet network, and the only physical connection between the two hosts is used, and it is no longer a shared media network, but a so-called P2P network, and there is no need for MAC addresses to exist on this network.

The differences between using a device MAC and a random MAC are: distinguishing personal identity, improving privacy protection, preventing cyber attacks, improving network security, and different scope of application.

1. Distinguish personal identity: When using the device MAC address, each person's device has a unique MAC address, so the MAC address can be used to distinguish the identity of the individual. When using a random MAC address, a new MAC address is randomly generated every time you connect to the network, making it impossible to distinguish the identity of an individual.

2. Improve privacy protection: Using a random MAC address can improve privacy protection, because a new MAC address will be generated every time you connect to the network, which can avoid being tracked. When using a device MAC address, each device has a unique MAC address, which can be exploited by hackers to track and attack.

3. Prevent network attacks: Use random MAC addresses to prevent some network attacks, such as MAC address spoofing attacks. MAC address spoofing is a type of attack that uses MAC address forgery, which can be avoided by using random MAC addresses.

4. Improve the security of the Walkzen network: Using a random MAC address can improve the network security because hackers cannot use the MAC address to attack. When using the MAC address of the device, hackers can use the MAC address to carry out attacks, such as ARP spoofing attacks.

5. Different scope of application: The MAC address of the device is suitable for some occasions that need to be connected to the network for a long time, such as home network, enterprise network, etc. The use of random MAC addresses is suitable for some occasions where the privacy needs to be protected, such as public WiFi, cafes, etc.