Improper Nic mode setting can also cause Switch Failure

Vswitches are still commonly used, so I have studied that improper Nic mode setting can also lead to vswitch faults. I would like to share with you here, I hope it will be useful to you. I got to work early in the morning, my ass was not stable yet, and the Office was full of ringtones. I used to have a few computers in my office to normally access the internet yesterday, that is, the Internet access speed is very slow. Many colleagues are eager to query information online, so they keep calling the author to solve the problem. After receiving the call, I did not say anything and quickly arrived at the fault site, invest in the rush to repair network faults.

Considering that this network failure is very urgent and the switch failure range is relatively large, the first thing I think of is the network virus, because once some viruses have occurred, all computers in the same subnet as the computer with a virus attack may fail over the Internet or slow access speed. With this worry, I did not think about it. I quickly found the latest version of anti-virus software and scanned and killed all computers with network faults one by one. After a long waiting for anti-virus, I did not find any virus shadow. Obviously, this large-scale network failure is not caused by the network virus.

After eliminating the virus, the author believes that although the failure has a wide range, not all computers in the LAN of the Organization have such a switch failure, after all, some office computers can still work normally. Therefore, I believe that the fault should belong to a specific phenomenon rather than a common phenomenon of LAN networks. According to this analysis, the author began to focus on some computers. The previous experiences in network troubleshooting told me that, if a computer that was able to access the Internet suddenly fails to access the Internet or the Internet speed is slow, it may be caused by three reasons: one is that the computer's operating system has problems, the second reason is that the stability of the network connection line is suddenly damaged. The last reason is that the network switch connected by the computer has a problem, now, the author will conduct one-by-one troubleshooting on the computers with switch faults from these three aspects.

From the computer operating system perspective, the only thing that can affect network connections is that the NIC Driver Installed in the computer system is suddenly damaged, or the computer's Internet access parameters are suddenly modified by other applications or human factors. Based on this analysis, I first open the Device Manager window of the system, find the NIC device installed on the local computer, and right-click it, run the "Uninstall" command (1) from the right-click menu that appears, so that the NIC Driver Installed in the local system can be completely deleted from the system; next, reinstall the original driver of the NIC as usual. After the NIC driver is installed, I open the network neighbor window of the local system, right-click the "local connection" icon and run the "properties" command from the shortcut menu to open the local connection Property setting window, click the "General" tab in the window, select the "Internet Protocol (TCP/IP)" option on the corresponding tab page, and click the "properties" button, open the attribute settings page, as shown in Figure 2. on this page, you must set the IP address and gateway address correctly, set the IP address of the DNS server, and set all network parameters, restart the computer system again. I thought this kind of effort could eliminate failures that cannot be connected to the Internet. But the facts tell me that such a fault is not caused by the software system. .

After removing the software system factors, I checked the network connection lines of the faulty computer. To prevent looseness of the network connection cable connector, I pulled the network cable connector from the NIC and forced it to be inserted again. However, the effect is not good at all; will it be that the network connection cable is broken midway through, or is there any other broken phenomenon? I don't want to worry about it. I used cables that could normally access the Internet to plug them into a computer with a switch failure, but the network failure still exists. Is there any possibility that the network card itself has a hardware fault? Considering that if a network card with a hardware fault is still connected to the network, broadcast information may be sent continuously to the network, is it because a large amount of junk broadcast information hinders normal network transmission?

With such doubts, I began to test whether the NIC device has hardware faults. As we all know, if the hardware of the network card is faulty, the IP address we assign to the network card cannot be pinged by the ping command. According to this standard, I first found that the IP address of a computer with a vswitch fault is "192.168.1.58", and then click "start"/"run" commands on the local computer. In the system running dialog box that appears, enter the string command "ping 192.168.1.58-t" and click the Enter key. In the figure 3 displayed, the local IP address can be pinged normally, this indicates that the NIC has no hardware problems.