Switch is a network device that can realize data exchange and transmission, and is used to transmit the data. It usually has several ports, which can be connected to many computers at the same time. It is often used to expand the ports of routers or set up local area networks. The Ethernet switch we often talk about is actually a multi-port layer 2 network device based on bridge technology, which provides a low-latency, low-overhead path for forwarding data frames from one port to another.
The working principle of switch
The main functions of Ethernet switches are learning, forwarding, filtering and eliminating loops.
Ethernet switches know the MAC addresses of devices connected to each port and map the addresses to the corresponding ports in the MAC address table in the switch cache. When the destination address of a data frame is mapped in the MAC address table, it is forwarded to the port connecting the destination node instead of all ports (if the data frame is broadcast/multicast, it is forwarded to all ports). When switches include a redundant loop, Ethernet switches use the spanning tree protocol to avoid the generation of loops while allowing backup paths.
1. Expand bandwidth, improve network speed
Through ethernet switch ports, it is possible for a few users to share the same 10Mb/s bandwidth, or even for only one user to hog 10Mb/s bandwidth, reducing or even eliminating the direct result of packet collisions on the network.
2. Low cost of deployment and installation
Ethernet switches use existing 10Mb/s Ethernet cable wiring, original network interface CARDS, hubs, and software to protect the original investment of enterprise networks.
3. Improve network security
Ethernet switch only sends packets to the port associated with the destination address of the packet. Users at other addresses do not receive communication. The degree of improvement in network security is greatest when each switch port supports a single user, or when virtual lANs are deployed.