Network combat: Let your network away from the frequent line of trouble

Refer to the Internet frequent drop line, I believe that many people will subconsciously think that the fault is due to poor line contact, but in the elimination of line factors, the network frequently dropped the phenomenon will sometimes still appear, when we encounter this phenomenon, in addition to observing the stability of the network equipment itself, Also need to pay attention to whether there are parameter conflicts in the network, especially whether the IP address of network equipment conflict, because this kind of resource conflict is not only easy to cause network transmission instability, and the network fault caused by this factor is difficult to be found and excluded in time. This is not, this article from the actual combat point of view, to contribute to you an IP address conflict caused by the network frequent drop-line fault phenomenon, as well as the breakdown of the phenomenon of the specific removal process, I hope that these content to you in the future of the troubleshooting to be inspired!

Failure phenomenon

Recently, the author for renting in the unit building inside a company upgraded router equipment, in order to enable the company through the router device access to the external network, the author deliberately connected it to the light cat and the core switch, so that all of the company's Internet information through the router to forward. Considering that the unit has been through ADSL dial-up to share the Internet, and ADSL modem equipment is directly connected with the switch, so the author of the router and the switch device after the connection, and the switch does not make any adjustments to the parameters, As a result, the test found that all workstations in the company were able to surf the web properly. I thought the upgrade of the network equipment was done so smoothly, but who would have thought that in a few days, the company's employees called to find the author, said that their unit network after upgrading the router device is always frequent failure phenomenon, this phenomenon occurs about every quarter of an hour, After the switch device and router device are shut down and restarted, the phenomenon of frequent line failure will disappear temporarily.

Fault analysis

After receiving the faulty call, the author immediately rushed to the failure phenomenon, and the phenomenon was patiently observed; According to the observation results, the author initially thought that similar to the pattern of the internet phenomenon, is likely to be caused by worms inside the network, in order to test whether this fault phenomenon is caused by network virus, The author immediately and the company responsible for the network of employees split up action, the network inside all the workstations for a thorough virus killing operations, after a long time to kill antivirus wait, we found that some of the workstations in the network do have worms "figure", full of this large-scale virus "strangulation action" will be harvested, However, after the Internet test, it was found that the intermittent network failure still exists.

After the network virus factors are excluded, the author will be suspicious target transferred to the network line connection, because if the network line connection improper, it is likely to cause network loop phenomenon, this phenomenon will lead to broadcast storm, the end may cause the network to appear frequent drop-line phenomenon. Think of here, the author immediately came to the switch and router equipment scene, carefully check whether there is the same network cable connected to the switch equipment at the same time, the results found that the network cable connection is normal; I am not at ease, and think of the network if the Workstation network card equipment damage and not timely removal It is also easy to cause the network broadcast storm phenomenon to occur, so the author will be connected to the switch equipment all network cable extraction, only the server connected with the network cable, the results found that the server can not only normal access to the external network, and continuous work for a long time also did not appear a drop-line phenomenon.