Working principle of switch The main functions of switch

A switch is a computer network device used to forward data packets in a local area network or wide area network. Its main function is to forward data packets from one computer to another computer to enable communication between computers. Switches come in many types and working modes, including traditional Ethernet switches, virtual local area network (VLAN) switches, fiber switches, etc. They play a key role in different network environments, helping network administrators manage, optimize and control data traffic.

Here’s how it works:

1. When the switch receives a data frame, it will decide which interface to send it to based on the destination MAC address, and after finding the target interface, it will send the data frame to that interface.

2. The switch has a forwarding table indexed by MAC address, which is used to record the physical interface corresponding to each MAC address. When the switch receives a new data frame, it will look up the forwarding table to determine the destination MAC address and find the physical interface corresponding to the address in the table.

3. If the physical interface corresponding to the destination MAC address does not exist in the forwarding table, the switch will broadcast the data frame to all other interfaces, learn the correspondence between the MAC address and the interface, and update the forwarding table.

4. The switch will also monitor network traffic in real time and perform congestion control based on network congestion conditions to prevent network congestion.

In short, the working principle of the switch is mainly to determine the transmission path of the data frame based on the destination MAC address and dynamically maintain the forwarding table to improve network performance.

The main function is to forward the received data frames to the target interface after the decision-making process, so as to realize the communication between different devices in the network. The main functions are as follows:

1. Forwarding data packets: The switch can forward data packets to the specified port according to the MAC address table, thereby realizing communication within the LAN.

2. Filter data packets: The switch can filter data packets based on MAC address, IP address, port and other information to achieve network security control.

3. Learning MAC addresses: By learning MAC addresses, the switch can establish a MAC address table to record the MAC address of each device and the port to which it is connected, thereby improving the efficiency of the switch in forwarding data packets and avoiding problems such as broadcasting and conflicts.

4. Link aggregation: The switch supports link aggregation technology, which combines multiple physical links into one logical link to improve network reliability and bandwidth.

5. VLAN division: The switch supports virtual LAN (VLAN) division, which divides a physical LAN into multiple logical LANs to achieve isolation and protection between different departments or applications.

6. Quality of Service (QoS): The switch supports QoS technology, which prioritizes data packets according to different service quality requirements to ensure the data transmission quality of important applications.

7. Network management: The switch supports management protocols such as SNMP and Telnet, and the switch can be configured, monitored and troubleshooted through network management software.