Do you understand the difference between the hub (HUB), Switch, Router (ROUTE)? This article is a simple introduction to you, let you have a clearer understanding of the above three when building a network or purchasing online products. The router, hub, and switches, there is no difference, you can connect multiple machines into the network. But their functionality in the network is completely different. After reading the full text, you fully understand. In order to better understand the following, there is something to understand that if the two computers use the same network protocol (such as TCP / IP) interconnected, there is basically no data clogging on the network, so the network performance between the system is relatively high. If more than 10 computers are connected to a local area network and use multiple protocols (such as TCP / IP, NetBeui, IPX, AppleTalk, etc.), and broadcast information often generates broadcast information. This will result in the data blockage of the network, which reduces the effective bandwidth of the network.
Hub (HUB)
The hub is the simplest between the three, its function is to connect multiple machines together. There are usually 4, 6, 8, 12, 16 ports on the hub. There will be more ports on some hubs. If you have 3 computers, you can use the hub to connect them simply and communicate with each other using TCP / IP protocols. This constitutes a simplest network. If the computer A is to send to the computer B, then in this network, the computer A first sent the data to the hub, and the hub will send the data to all ports except A, which means the computer B, computer C received the data of computer A. The computer C found that the packet is not sent to it, immediately discard the packet; computer B is discovered that the packet is sent to it, accept it. After the computer B receives the information, it will send a confirmation message to the computer A, and the same message will also be transmitted to the computer C. So, if the hub is connected to many computers, then a large number of broadcast information is generated, and the efficiency of the network is greatly reduced.
Advantages: * Use hub connection networks is the most convenient and simplest way. No need to do any changes, just insert the network cable into the hub interface. * Hub price is very cheap, is a small network (2 - 5 computers) most effective way of connection ..
Disadvantage: * The hub reduces the effective bandwidth of the network because all ports use the same network path. * If you use the broadcast protocol in your network, data conflicts and blockages are often occurring between networks. * Different hub vendors have different standards (most of them), some hubs specify that the connected network cables cannot exceed 50 meters, and so on.
Switch (switch)
Now let's take a look at the principles of the switch. The switch inside the switch saves a routing table, and the information of each port is recorded in the routing table. If the computer A is to send information to the computer B, the switch is transferred directly to the computer B based on the information of the routing table.
The switching speed of the switch is much faster than the hub. It can handle multiple data requests at the same time. Even if the switch is connected to the computer, it will not have a big impact on the bandwidth of the network, and the conflict between the network is greatly reduced. In the network, if there are two machines to send data in a network, data conflicts are generated. Such as computer B, computer C simultaneously transmits data to computer A, resulting in data conflicts. After conflicting, computer B and Computer C will give up this transfer, then listen to the network. If there is no other machine in the network, the information can be sent again. It can also be seen from this point that in the hub, each port uses the same network path, so it is easy to conflict. If the system uses TCP / IP protocols, after conflicts, the machine will wait for a while and then send data again. And after the sending machines are confirmed, other machines can use the network path. Creating conflicts uses the "binary index retransmission" algorithm (herein, you can see related articles) to reduce the probability of reproducing conflicts. However, if the hub is connected to 25 computers, even if the "binary index retransmission" algorithm is used, there will be many conflicts generation, which causes network performance to decline. Therefore, in this case we use the switch to replace the hub because the switch directly transmits data according to the routing table, greatly reduces conflicts.
Router
In the same network, the router is usually not used. Of course, you can use this, this is like going to work more than a plane, and the company and home are only a few minutes. ^ _ ^ The main function of the router is to connect to different networks. For example, private I P networks can be connected to a public IP network via a router. The router is connected to two different networks. If the destination sent by the computer A is not in the same network, the data will forward to another network via the router.
Data Different from different networks, the switch is different, the router will process the transmitted packet, which means that the router can send a packet to the port specified by the machine, for example, the router can put HTTP data (Usually 80 ports) is sent to other ports. Some routers have packet filtering functions. There is a small operating system inside each router, and the router can be set and optimized by this operating system.
