E-link PoE Switche

1. The deduction

When we face the failure phenomenon and analyze the problem, we have unintentionally learned to use the elimination method to determine the direction of the failure.This method is to list all possible faults as comprehensively as possible according to the observed fault phenomena, and then analyze and eliminate them one by one.When eliminating, should follow the principle from simple to complex, improve efficiency.This method can be used to cope with a variety of failures, but maintenance personnel need to have a strong logical thinking, a comprehensive and in-depth understanding of switch knowledge.

2. Correlation method

The so-called comparison method is to use the existing Ethernet switches of the same model that can operate normally as the reference object and compare them with the fault switches, so as to find out the fault points.This method is simple and effective, especially in the case of system configuration failures. A simple comparison can be made to identify configuration differences, but sometimes it is not easy to find a switch with the same model and configuration.

3. The substitution method

Replacement is the method of finding fault points by replacing potentially faulty components with normal Ethernet switch components.It is mainly used for the diagnosis of hardware faults, but it should be noted that the replacement parts must be the same brand, the same model of the same kind of switch.

Of course, in order to make the troubleshooting work has rules to follow, can be in the fault analysis, should be analyzed according to the following principles.

(1) from the outside to the inside, if there is a fault in the switch, we can first identify from the various indicators on the outside, and then according to the fault indication, to check whether there is a problem in the corresponding parts inside.No matter whether the fault can be detected from the outside, the switch must be logged in to determine the specific fault and take corresponding measures to remove the obstacle.

(2) from soft to hard fault, who do not want to easily on the screwdriver to remove the switch again, so in the inspection, always from the system configuration or system software on the investigation.If the software doesn't solve the problem, the hardware does.For example, if a port is not available, we can first check whether the port the user is connected to is not in the corresponding VLAN, or whether the port is closed by another administrator, or other reasons on the configuration.If you rule out the system and configuration possibilities, you suspect that the real problem is a hardware failure.

(3). First easy then difficult in the case of more complex fault analysis, must first from simple operation or configuration to eliminate.This can speed up the speed of troubleshooting, improve efficiency.