First, the network itself
The target website you want to connect to is located on a server with insufficient bandwidth or heavy load. The solution is simple, please change the time or change the target website.
Second, the network cable problem caused the network speed to slow down.
As we know, twisted pair is composed of four pairs of wires tightly twisted together according to strict regulations to reduce the influence of crosstalk and background noise. Meanwhile, in T568A standard and T568B standard, only four wires of twisted pair 1 2 and 3,6 are used, in which 1 2 is used for transmission, 3,6 is used for reception, 1 2 must come from one winding pair, and 3,6 must come from one winding pair. In this way, crosstalk can be avoided to the maximum extent and data transmission can be guaranteed. In practice, I found that the network cable not made according to the correct standards (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 was normal at first, but after a while, the network speed slowed down. The latter situation is very obvious on desktop computers, but it is normal to check the network speed with laptop computers. After years of practice, I found that the slow network speed caused by the network cable not made according to the correct standard is also related to the quality of the network card. Generally, the network card performance of desktop computers is not as good as that of notebook computers. Therefore, when using the switching method to troubleshoot, using a laptop to detect the normal network speed cannot rule out the problem that the network cable is not made according to the standard. We now require all network cables to be suppressed according to T586A and T586B standards, and notebook computers cannot be used instead of desktop computers for fault detection.
Third, there is a loop in the network, which causes the network speed to slow down.
When the number of nodes involved in the network is small and the structure is not very complicated, this phenomenon rarely occurs. However, in some complex networks, there are often redundant spare lines, which will form a loop if they are inadvertently connected. For example, the network cable is connected from the network center to the computer room 1, and then from the computer room 1 to the computer room 2. At the same time, there is a backup line directly connected to the computer room from the network center. If these lines are connected at the same time, it will form a loop, constantly sending and checking packets, thus affecting the overall network speed. This situation is hard to find. In order to avoid this situation, we are required to develop good habits when laying network cables: the network cables should be clearly marked, and records should be made where there are spare cables. When this kind of fault is suspected, the method of partition step by step is generally adopted.
Fourth, the broadcast storm caused by the hardware failure of network equipment leads to the slow network speed.
As the main means of discovering unknown devices, broadcasting plays a very important role in the network. However, with the increase of the number of computers in the network, the number of broadcast packets will increase dramatically. When the number of broadcast packets reaches 30%, the transmission efficiency of the network will decrease obviously. When the network card or network equipment is damaged, broadcast packets will be sent continuously, which will lead to a broadcast storm and paralyze network communication. Therefore, when the hardware of the network equipment fails, the network speed will also slow down. When this kind of fault is suspected, the hub or switch can be replaced by replacement method to eliminate the fault of hub equipment. If these devices are not faulty, after turning off the power of the hub or switch, use the "Ping" command under DOS to test the computers involved one by one, find the computers with faulty network cards, and replace them with new network cards to restore the normal network speed. Network cards, hubs and switches are the most prone to failure and slow down the network.
Five, a port in the network has formed a bottleneck, resulting in slower network speed.
In fact, router WAN port and LAN port, switch port, hub port and server network card may all become network bottlenecks. When the network speed is slow, we can use network management software to check the data flow of routers, switches and server ports during the peak period of network use; You can also use the Netstat command to count the data traffic of each port. On this basis, the location of network data circulation bottleneck is determined, and its bandwidth is managed to increase. There are many specific methods, such as changing the server network card to 100M or 1000M, installing multiple network cards, dividing multiple VLAN, changing the router configuration to increase bandwidth and so on. , which can effectively alleviate the network bottleneck and maximize the data transmission speed.
Sixth, the influence of the worm virus causes the network speed to slow down.
Worms spread by mail have a more and more serious impact on the network speed, which is extremely harmful. This virus causes infected users to keep sending emails as soon as they get online. The virus randomly selects documents from the user's personal computer and attaches them to random addresses in the user's computer address book to send emails. Hundreds of such junk mails were sent out in line, and some of them were returned in batches and piled up on the server. As a result, individual backbone Internet appears obvious congestion, and the network speed obviously slows down, which makes the local area network almost paralyzed. So be sure to upgrade antivirus software in time; Computers should also upgrade and install system patches in time, uninstall unnecessary services, and close unnecessary ports to improve the security and reliability of the system.
Seven, excessive use of firewalls
Excessive use of firewalls will also slow down the network speed. Needless to say, uninstall unnecessary firewalls and keep only one powerful enough.
Eight. Insufficient system resources
You may have too many applications loaded to run in the background. Please load the software reasonably or delete useless programs and files to release resources, so as to improve the network speed.