Please briefly describe how hubs, routers, switches work

Use of networked devices.

The difference between a switch and a hub.

First, from the perspective of OSI architecture.

Hubs belong to Layer 1 physical layer devices, while switches belong to Layer 2 data link layer devices of OSI.

Second, from the perspective of working methods.

The hub is a broadcast mode, that is to say, when a certain port of the hub is working, all other ports can listen to the information, which is easy to produce broadcast storms, and the network performance will be greatly affected when the network is large;

The switch can avoid this phenomenon, when the switch is working, only the port that makes the request and the destination port respond to each other without affecting other ports, so the switch can isolate the collision domain and effectively suppress the generation of broadcast storms.

Third, from the perspective of bandwidth.

No matter how many ports there are in the hub, all ports share a bandwidth, and only two ports can transmit data at the same time, and the other ports can only wait, and the hub can only work in half-duplex mode;

For the switch, each port has an exclusive bandwidth, when the two ports work does not affect the work of the other ports, and the switch can not only work in half-duplex mode but also work in full-duplex mode.

The role of hubs and switches.

The main function of the hub is to regenerate and amplify the received signal to expand the transmission distance of the network, and at the same time concentrate all nodes on the node centered on it.

Like hubs, switches provide a large number of ports for cable connection, which allows for star topology cabling.

The main function of the switch is to act like repeaters, hubs and bridges, when it is framed, the switch will regenerate an undistorted square electrical signal. Like bridges, switches use the same routing or filtering logic on each port.

Like bridges, switches divide the LAN into multiple collision domains, each of which has its own bandwidth, thus greatly increasing the bandwidth of the LAN.

In addition to the functions of bridges, hubs, and repeaters, switches offer more advanced features such as virtual local area networks (VLANs) and higher performance.

Let's start with the hub, which is the hub. Its function can be simply understood as connecting some machines to form a local area network. Switches (a.k.a. switched hubs) do much the same thing as hubs.

However, there is a difference in performance: hubs work in the style of shared bandwidth, while switches use dedicated bandwidth.

In this way, when there are many machines or a large amount of data, the two will be more obvious.