network is now very popular. Everyone uses it every day. Sometimes, I feel that my network speed is particularly bad. Today I will analyze the reasons for the slow speed of the network: Network itself problem The server on which you want to connect to the target site is under- or under-loaded. The solution is very simple, please change the time period or change the target website. Second, the network cable problem causes the network speed to slow down. We know that the twisted pair cable is tightly twisted together by four pairs of wires according to strict regulations to reduce the influence of crosstalk and background noise. At the same time, only the 1, 2, and 3, and 6 lines of the twisted pair are used in the T568A standard and the T568B standard, where 1, 2 is used for transmission, 3, 6 is used for reception, and 1, 2 must be from a winding. Yes, 3, 6 must come from a pair. Only in this way can crosstalk be avoided to the maximum extent and data transmission is guaranteed. In practice, I found that the network cable that is not made according to the correct standard (T586A, T586B) has great hidden dangers. The performance is as follows: in one case, the network speed is very slow when it is first used; in another case, the network speed is normal, but after a while, the network speed is slow. The latter case is very obvious on a desktop computer, but the network speed is normal when checked with a laptop. For this problem, I have found through many years of practice that the slowdown of the network speed caused by the network cable not produced according to the correct standard is also related to the quality of the network card. Generally, the performance of a network card of a desktop computer is not as good as that of a notebook computer. Therefore, when using the exchange method to troubleshoot, the use of a laptop computer to detect the normal network speed does not preclude the problem that the network cable is not manufactured according to standards. We are now required to press the T586A, T586B standard to suppress the network cable, in the detection of failure can not always use a laptop instead of a desktop computer. Third, the existence of loops in the network causes the network speed to slow down. When the number of nodes involved in the network is not many, and the structure is not very complicated, this phenomenon generally occurs rarely. However, in some more complicated networks, there are often redundant backup lines, such as loops when inadvertently connected. For example, the network cable is connected to the computer room from the network center, and then the computer room is connected to the computer room. At the same time, there is another backup line from the network center directly connected to the second room of the computer. If these lines are connected at the same time, it constitutes a loop, and the data packet will continuously send and verify data, thereby affecting the overall network speed. This situation is difficult to find. In order to avoid this, we must develop good habits when laying the network cable: the network cable is marked with obvious labels, and the place with spare lines should be recorded. When such a failure is suspected, the method of stepwise segmentation is generally adopted. Fourth, network equipment hardware failure caused by broadcast storms and slow network speed As the main means of discovering unknown devices, broadcasting plays a very important role in the network. However, as the number of computers in the network increases, the number of broadcast packets will increase dramatically. When the number of broadcast packets reaches 30%, the transmission efficiency of the network will be significantly reduced. When the network card or network device is damaged, the broadcast packet will be sent continuously, which will cause a broadcast storm and paralyze the network communication. Therefore, when the network device hardware is faulty, the network speed will also be slowed down. When such a failure is suspected, the replacement method can be used to replace the hub or switch to eliminate the fault of the hub device. If these devices are not faulty, after turning off the power of the hub or switch, use the “Ping” command to test the computers involved one by one, find the computer with the faulty network card, and replace the new network card to restore the network speed. NICs, hubs, and switches are the most prone to failures that cause slower network speeds. 5. A port in the network forms a bottleneck, causing the network speed to slow down. In fact, router WAN ports and LAN ports, switch ports, hub ports, and server NICs may become network bottlenecks. When the network speed is slow, we can use the network management software to check the data traffic of routers, switches, and server ports during peak network usage. Netstat commands can also be used to collect data traffic of each port. Based on this, confirm the location of the network data flow bottleneck and try to increase its bandwidth. There are many specific methods, such as replacing the server network card with 100M or 1000M, installing multiple network cards, dividing multiple VLANs, changing router configuration to increase bandwidth, etc., all of which can effectively alleviate network bottlenecks and maximize data transmission speed. Sixth, the impact of worms causes the network speed to slow down. The worms distributed by E-mail have an increasingly serious impact on network speed and are extremely harmful. The virus causes the infected user to send emails as long as they are on the Internet. The virus selects a random document in the user's personal computer and attaches it to the random address of the user's address book for mail transmission. Hundreds of such spam messages were sent out in teams, and some were returned in batches and piled up on the server. As a result, the individual backbone Internet has obvious congestion, and the network speed has become significantly slower, making the local area network close to the embarrassment. Therefore, we must upgrade the anti-virus software used in time; the computer should also be upgraded in time, install system patches, uninstall unnecessary services, and close unnecessary ports to improve system security and reliability. Seven, the excessive use of the firewall too much use of the firewall can also cause the network speed to slow down, the handling method need not say more, the unnecessary firewall under the uninstall only retains a powerful enough. Eight, the system resources are insufficient You may load too many applications to run in the background, please load the software reasonably or delete the useless programs and files, and vacate the resources to achieve the purpose of increasing the network speed.