What is the function of mac address

The role of the mac address is to identify a specific network node. The MAC address is an address used to confirm the location of a network device. The mac address is consistent with the hardware to a certain extent and is based on physics. When computers communicate with each other, the address resolution protocol is responsible for mapping IP addresses to MAC addresses when transmitting data packets between nodes.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

MAC address (English: Media Access Control Address), literally translated as media access control address, also known as LAN Address, MAC address, Ethernet Address or physical address (Physical Address), which is an address used to confirm the location of a network device. In the OSI model, the third network layer is responsible for IP addresses, and the second data link layer is responsible for MAC addresses. The MAC address is used to uniquely identify a network card in the network. If a device has one or more network cards, each network card needs and will have a unique MAC address.

The role of mac address:

The MAC address is consistent with the hardware to a certain extent. It is based on physics and can identify specific network nodes.

Most of the ways to access the Internet are to organize hosts together through a LAN, and then connect them to the Internet through devices such as switches or routers. This raises the question of how to distinguish specific users and prevent IP addresses from being stolen. Since the IP address is only a logical identifier and can be modified by anyone, it cannot be used to specifically identify a user. The MAC address is not the case. It is fixed in the network card. Theoretically, unless the hardware, namely the network card, is stolen, it generally cannot be impersonated. Based on this characteristic of the MAC address, the LAN adopts the method of using the MAC address to identify specific users.

In the specific communication process, the MAC address and IP address are matched one-to-one through the exchange table inside the switch. When there is a data packet sent to a host in the local LAN, the switch first receives the data packet, then maps the IP address in the data packet to a MAC address according to the corresponding relationship in the switching table, and then forwards the data packet to the corresponding The MAC address of the host goes up. In this way, even if a host steals the IP address, it will not be able to receive the data packet because it does not have a corresponding MAC address. The sending process is similar to the receiving process.

So, whether it is a local area network or a wide area network, when computers communicate with each other, the final performance is that the data packet starts from an initial node on some form of link and is passed from one node to another. A node is finally transmitted to the destination node. The transmission of data packets between these nodes is completed by ARP (Address Resolution Protocol) which is responsible for mapping IP addresses to MAC addresses.

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