Upgrade the switching system to solve frequent disconnection failures

Bkjia.com exclusive Article] With the continuous improvement of the information technology level of the Organization, the requirements for signal processing capabilities and network transmission speed are constantly improved, and the quality and performance requirements of switches naturally rise. However, the quality and performance of vswitches over time cannot meet the increasing data exchange requirements of the organization. After a long time, there will also be software and hardware problems, which will directly lead to various strange faults in the network. The frequent disconnection network failure described below is caused by the interruption of the switch port due to the low background version of the switch system, now I will restore the troubleshooting process and share it with you!

Building Network Conditions

A network in a building has a central data center. The core route switch in the central data center is mounted with multi-mode optical fiber cables, which are directly connected to three-layer switches in the weak current room on each floor, all computers on each floor are connected to layer-3 switches in the weak current room through M common twisted pair wires. The first, second, and third-layer networks have a relatively early networking time, And the switches used for the corresponding floor networks have been working for a long time, in the past, the fourth and fifth floors of the building were event centers and conference rooms. Due to work requirements, the Unit has transformed these two floors into common office rooms, the computers in these rooms are also connected to the three-tier switch in the weak current room through M common twisted pair wires, but the three-tier switches on these two floors are the latest, the version corresponding to the background management system is naturally the latest.

A floor suddenly fell offline

At ordinary times, users on all floors can access the Internet normally, and the speed is also very smooth. However, recently, the network administrator found that users on the third floor were repairing network faults one after another, saying that their computers could not normally access the internet. At the beginning, the Network Administrator simply thinks that the fault must be caused by the Internet users themselves. Therefore, it is recommended that these users who cannot access the Internet carefully check whether their computers have viruses and whether the network connection is secure, if this is not the case, you can change the new IP address again. I thought these suggestions could help the Internet users solve the fault. However, the fault repair hotline for users on the third floor is continuously coming in, at the same time, the network administrator can feel the seriousness of the problem because the number of users cannot access the Internet is more.

As many users on the third floor cannot access the Internet at the same time, the network administrator Thinks That the ARP virus may exist in the sub-network on the third floor, because the ARP virus is very popular nowadays, in addition, once the LAN is infected with this type of network virus, multiple computers may not be able to access the Internet at the same time. In the spirit of a try, the network administrator wants to first enter the core switch of the building network, use its own management commands to check the switch's background log records to see if there is an address conflict caused by ARP virus. Once you see an address conflict record, it indicates that there is actually ARP virus in the building network. However, after careful check, the network administrator did not find the corresponding record content, which indicates that there is no ARP virus in the building network, otherwise, users on the third floor may be unable to access the Internet normally ".

After eliminating the network virus, the network administrator began to worry that the layer-3 switch located in the weak current room on the third floor may not work normally, the network administrator wants to restart the backend System of the target switch on the third floor to check whether the user cannot access the Internet. Therefore, the network administrator immediately logs on to the back-end system of the core switch of the building network, then run the interface command to enter the downstream port of the Target layer-3 Switch. In this port mode, run the "reboot" command to remotely restart the background System of the Target layer-3 switch, the result shows that computers that were not able to access the Internet can now access the Internet normally. It seems that the status of the Target layer-3 switch is faulty, resulting in a sudden disconnection of users on the third floor.

Frequent disconnection of network image

I thought that the online fault had been solved successfully, but who once thought that it was not long before, the same fault again, and every time, the network administrator can either rush to the faulty switch or restart the background management system of the target switch remotely, so that the disconnection fault can be solved temporarily, it seems that the problem is not simply restarting the switch system.

Is there a large amount of data traffic in the working subnet on the third floor? during a period of time, layer-3 switches on the corresponding floor are overwhelmed by large data volumes? To monitor the existence of large-volume data in the working subnet on the third floor, the network administrator uses professional tools to monitor the traffic of the subnet in real time, he found that the network traffic is not very large, and even more incredible, the network disconnection may occur frequently during off-duty hours, this indicates that the layer-3 Switch on the third floor is not terminated by large-volume data packets. In this case, is someone deliberately attacking the switch or is the performance of the switch unstable?

Suspect that the system version is earlier

Considering that the layer-3 Switch on the third floor is connected to the core switch of the building through the broadband optical fiber line, will it be a problem of broadband optical fiber? For the sake of security, the network administrator asks the local operator to test the broadband line between the switch on the third floor and the core switch of the building. After repeated tests, it is found that the connection performance of the broadband cable is stable, this means that the switch working status on the third floor has nothing to do with the connectivity of the broadband optical fiber.

Because the traffic on the working subnet on the third floor is not large, and restarting the switch background system can temporarily solve the fault, the network administrator thinks that the problem lies in the stability of the target switch, which factors will affect the stability of the switch? When thinking hard, the network administrator accidentally thought that the switch on the third floor had also experienced a fault, that is, the switch was unable to access the Internet for a long time due to system bugs, when the switch was still under warranty, the network administrator saw it took a long time for the system integration staff to find out the cause of the fault. After patching the switch system, solved the fault that the user on the third floor cannot access the Internet normally. The network fault occurred this time is somewhat similar to the previous one. are the causes of the fault the same? It seems that the target switch on the third floor has been working for a long time, and its background management system has been running until now, and many bugs may have been found. Are these bugs solved, can the above network faults be solved?

In order to determine whether your guess is correct, the network administrator immediately goes to The Faulty Switch site, directly enters the switch background system through the Super Terminal mode, and in the global configuration status of the system, run the "dis ver" command to check the version number of the faulty vswitch's background system. After you write down the version number, the network administrator queries the version of the background System of the corresponding vswitch on the Internet, several versions of the background system used by the faulty switch have been upgraded. Is the above fault caused by the version of the switch background system being too low?

Upgrade switch system version

Although the network administrator cannot confirm that the above fault is caused by the low version of the switch background system, he believes that the latest version of the background system has fewer bugs and they will naturally run more stably, so he decided to upgrade the background System of the faulty switch to the latest version. To achieve this, the network administrator first downloads the latest version of the upgrade file from the official website of the switch, sets the local computer to an FTP server, and then logs on to the faulty switch through the Super Terminal, the upgrade file is transmitted to the flash memory of the switch through its built-in ftp command. To ensure the security of the upgrade operation, the network administrator backs up the previous configuration files of the faulty switch, to avoid the failure of the upgrade operation and fail to restore the switch's working status, use the boot command to officially upgrade the background management system of the faulty switch.

After the upgrade is completed, the Network Administrator executes the "dis ver" command and finds that the background System of The Faulty Switch has indeed been upgraded to the latest version, the Faulty Switch is reconfigured after the upgrade. After the configuration is complete, it is restarted again. After the faulty switch is stable, the Network Administrator tried to test the Internet access from the working subnet on the third floor. The test showed that the computer that had previously been unable to access the Internet had been able to access the Internet normally. Later, the network administrator continued the follow-up test, the result shows that the upgraded vswitch has been operating stably, and the users on the third floor have been surfing the internet normally, this indicates that the Network Fault mentioned above is indeed caused by a low vswitch background system version.