5 Common Failures of Network Switches and Solutions

As the key equipment of the network, network switch is inevitable to have problems occasionally, but we should deal with them in a timely manner after they occur, find out the fault point as soon as possible, and eliminate the fault. To achieve this, you must understand the types of network switch failures and the ability to analyze and handle failures. Generally speaking, common failures of network switches include power failure, port failure, module failure, circuit board failure and backplane failure.

1. Power failure

The power supply is damaged or the fan stops running due to instability of external power supply, aging of power supply circuit or lightning stroke, which makes it unable to work normally. Or other components in the network switch may be damaged due to the power supply.

If the POWER indicator on the network switch panel is green, it indicates that it is normal; If the indicator is off, the switch is not powered normally. Such problems are easy to find, solve and prevent.

For this kind of fault, we should first do a good job in the supply of external power, generally by using independent power lines to provide independent power, and add regulators to avoid transient high-voltage or low-voltage phenomenon. If conditions permit, UPS (uninterruptible power supply) can be added to ensure the normal power supply of the network switch. Some UPS provide voltage stabilizing function, while others do not. Please pay attention to the selection. Professional lightning protection measures shall be set in the machine room to avoid lightning damage to the network switch. Now there are many professional companies doing lightning protection engineering, which can be considered when implementing network wiring.

2. Port failure

This is the most common hardware failure. Be careful when plugging and unplugging connectors, whether it is an optical fiber port or a twisted pair RJ-45 port. If the optical fiber plug is dirty carelessly, the optical fiber port may be polluted and normal communication may not be possible. We often see that many people like hot plug connectors. Theoretically, it is OK, but this also inadvertently increases the incidence of port failures. Careless handling may also result in physical damage to the port. If the crystal head purchased is too large, it is easy to damage the port when inserting the networkswitch. In addition, if a section of twisted pair connected to the port is exposed to the outside, in case this cable is hit by lightning, it will cause the connected network switch port to be damaged, or cause more unpredictable consequences.

In general, a port failure is a failure of one or more ports. Therefore, after troubleshooting the computer connected to the port, you can determine whether it is damaged by replacing the connected port. In case of such failure, the port can be cleaned with alcohol cotton ball after the power is turned off. If the port is damaged, you can only replace it.

3. Module failure

The network switch is composed of many modules, such as stack module, management module (also called control module), expansion module, etc. The probability of failure of these modules is very small, but once problems occur, they will suffer huge economic losses. Such failures may occur if the module is inserted or unplugged carelessly, or the network switch is collided when handling, or the power supply is unstable.

When troubleshooting such faults, first ensure that the power supply of the network switch and modules is normal, then check whether each module is plugged in the correct position, and finally check whether the cables connecting the modules are normal. When connecting the connection management module, you should also consider whether it uses the specified connection rate, whether there is parity check, whether there is data flow control and other factors. When connecting the expansion module, you need to check whether the communication mode matches, such as whether full duplex mode or half duplex mode is used. Of course, if the module is confirmed to be faulty, there is only one solution, that is, contact the supplier immediately for replacement.

4. Circuit board failure:

The network switch is generally composed of the main circuit board and the power supply circuit board, and the fault is generally caused by these two parts. The main factors that cause the circuit board to fail to work normally are: the components on the circuit board are damaged or the base plate is poor, the hardware is inappropriate, the type of circuit board is inappropriate after the hardware is updated and due to compatibility problems.

Solution: First, determine whether the main circuit board or the power supply circuit board has a problem. Then, check the power supply part. Use a multimeter to power on and measure when the load on the main circuit board is removed to see whether the measured indicators are normal. If not, use an AT power source, input the power to the main circuit board, and the indicator on the front panel of the switch returns to normal brightness and color. The connected computer exchanges visits normally, That means there is a problem with the power supply circuit board. If the above operation fails, the problem should be on the main circuit board.

5. Backplane fault

Each module of the network switch is plugged into the backplane. If the environment is humid, the circuit board is short circuited due to moisture, or components are damaged due to high temperature, lightning and other factors, the circuit board will not work properly. For example, poor heat dissipation performance or too high ambient temperature cause the temperature inside the machine to rise, resulting in burned components. When the external power supply is normal, if all internal modules of the network switch cannot work normally, it is likely that the backplane is broken. In this case, the only way is to replace the backplane.

In a word, it is difficult to enumerate the faults of a network switch one by one. There are also some faults caused by wire faults and improper configuration. The above network faults, analysis and troubleshooting methods provide some ideas for us to sort out and solve the faults in the network. In addition to relevant theoretical knowledge, the judgment and solution of network faults also need the experience accumulated at ordinary times to help us find the root of the problem as soon as possible.