Analysis of common failures of network equipment
1. Improper wire selection causes network instability, failure analysis and elimination.
The following are the faults that the author has personally experienced. Although the solution is very simple, I still think it is necessary to put it here to give you a reference. In the group company's network, there is a dormitory building separated from the switch to the PC of the workstation, and the visual wiring distance is about 100. The five types of unshielded wires commonly used in the market are used. Both ends use the 568B standard as a crystal head. After the line is connected, the workstation prompts that the cable is unplugged, but sometimes the cable is connected because the router has DHCP enabled. When viewing the IP address assignment of the workstation, you can see the correct IP address assigned by the router, but you cannot browse the web.
Because I was worried about the wiring distance during wiring, I did not take many detours in this situation. I just set the speed of the workstation's network card to 10m duplex and the network worked normally. After that, another PC on the workstation also needs to access the Internet. I just went to the market and bought a 10M HUB for 60 yuan, the problem was solved, and there was no need to limit the speed of the network card. The network speed is reduced to 10M.
The above example tells us that sometimes making a little sacrifice is a good way to solve the problem. At the expense of network speed, the network has become normal and stable.
2. ADSL access, the router can not dial the fault.
An office network, ADSL access broadband, connected through a router and an 8-port switch. ADSL dials up through PPPoE. Using the dialing software provided by the telecom operator, it can quickly dial up, but with the built-in dialing program of the router, it is often found that dialing is unsuccessful.
When such a fault occurs, sometimes as long as the power of the ADSL device and the router are respectively connected and wait for one time, the router will automatically dial successfully, analyze the cause, and be affected by the electrical performance of the router, which will affect the working stability of the ADSL device. Normally, if dialing is successful, dialing is unsuccessful due to router access. After looking for coordination with the telecommunications department, after replacing the telephone line, the network became stable, and disconnections and inability to dial were rare.
3. Static electricity causes loss of router setting parameters.
The local area network of the subsidiary company of the group company is accessed by ADSL pppoe, and the Internet is shared by the U160 R160 router. The entire network has a total of 14 machines. The router is connected to the 16-port switch of the one-dimensional network. All computers are connected to the router through the switch. , Without any failure, but recently there has always been a failure due to loss of router configuration parameters leading to the failure to access the Internet. Inadvertently see all the network equipments are placed behind the computer desk, and are intricately placed with the computer's connection line, consider it may be caused by static electricity, then put the router and switch aside, clean up after power off, Re-fixed and installed, the fault is resolved.
4. The HUB port is damaged, causing the network to fail.
An enterprise's network is connected by a non-shielded Category 5 cable from the main office building to the production building. Considering that there are not too many machines in the production building, it abandoned the switch and adopted a 5-port HUB. After a thunderstorm, there was a machine that didn't connect to the Internet normally. The network card was not lit. When the network card was replaced, the light was on, but the network was still inaccessible. I was puzzled. Unplugged the network cable unintentionally. Only then did I realize that the HUB's port broke down, replace the other port, and the fault was resolved.
12V Detachable Plug Power Adapter are Ultra-small, easy to carry.Lightweight, comes with plug, easy to uses.enVironmentally friendly circuit design; products beautiful and generous, high temperature flame retardant shell, the use of ultrasonic welding, the use of safe and reliable.100% enVironmentally friendly materials, all products are not contained (and does not exceed the proVisions, restrictions) European restrictions / disabled cadmium, chromium, lead, PBB, PBDE six toxic substances.Wide input Voltage range, consistent with global standards.Insulation performance, high electrical strength.With short circuit, oVerload, oVerVoltage protection.Full load high temperature burner, 100% aging test.
12V Detachable Plug Power Adapter
12 Volt Adapter,Ac Adapter 12V,12V Ac Adapter,12V Dc Power Adapter
Shenzhen Juyuanhai Electronic Co., Ltd. , https://www.powersupplycn.com