Learn the concepts and principles of data network Ethernet Switches

Ethernet switches are still commonly used. So I have studied the concept and principle of the data network Ethernet switch. I will share it with you here, hoping it will be useful to you. Switching) refers to the technology collectively used to send the information to be transmitted to the corresponding route that meets the requirements according to the needs of transmitting information at both ends of the communication. Generally, an Ethernet switch is a device that performs information exchange in a communication system.

In computer network systems, the concept of exchange is an improvement of the shared working mode. The HUB we have previously introduced is A shared device. The HUB itself cannot identify the destination address. When A host in the same LAN transmits data to host B, data packets are transmitted in a HUB-based network in broadcast mode. Each terminal verifies the address information of the data packet header to determine whether to receive the data packets. That is to say, in this way, only a group of data frames can be transmitted over the network at the same time. If a collision occurs, retry. This method is shared network bandwidth.

The vswitch has a high-bandwidth back bus and an internal switching matrix. All ports of the Ethernet switch are attached to the back bus. After the control circuit receives the data packet, the processing port will look for the address table in the memory to determine the hardware address of the target MAC Nic) the port on which the NIC is attached. data packets are quickly transmitted to the destination port through the internal switching matrix. If the destination MAC does not exist, the packets are broadcast to all ports, after receiving the port response, the Ethernet switch "learns" the new address and adds it to the internal MAC address table.

Using an Ethernet switch, you can also segment the network. By comparing the MAC address table, the Ethernet switch only allows necessary network traffic to pass through the switch. Through the filtering and forwarding of Ethernet switches, the broadcast storm can be effectively isolated to reduce the occurrence of incorrect packets and wrong packets and avoid sharing conflicts.

A vswitch can transmit data between multiple port pairs at the same time. Each port can be considered as an independent network segment, and the network devices connected to it enjoy all the bandwidth alone, so they do not need to compete with other devices. When node A sends data to node D, Node B can send data to node C at the same time, and both transmission enjoy all the bandwidth of the network and all have their own virtual connections. If a 10 Mbps Ethernet switch is used here, the total traffic of the switch is 2*10 Mbps = 20 Mbps. When a 10 Mbps shared HUB is used, the total traffic of a HUB does not exceed 10 Mbps.

In short, a vswitch is a network device that can encapsulate and forward data packets based on MAC address recognition. An Ethernet switch can "Learn" MAC addresses and store them in an internal address table. By creating a temporary exchange path between the initiator of a data frame and the Target receiver, make the data frame directly arrive at the destination address from the source address.