Network troubleshooting caused by vswitch transient connection

The customer reported repair for network faults caused by the switch's short connection, and the network was suddenly paralyzed. Some computers could not access the Internet, and it was determined that a switch was closed, so they had to fix the network, pick out the ports that cannot access the Internet and re-connect to the new switch. However, some computers may encounter network printing failures and cannot be printed. Check the ping packet and find that the packet loss rate is serious, it's almost stuck. Check the new switch and replace it. After the temporary relief, intermittent network blocking continues, eliminating the possibility of switches and starting to troubleshoot network interfaces one by one, first, unplug all the Jumpers transferred to the new switch, observe the ping packet, the network is unblocked, lock the fault in the network cable pulled out from the pile, and check the ping packets one by one, when a ping begins to experience disconnection congestion, stop inserting other network cables and repeat a network cable to check the clients corresponding to this network port .... so far... the phenomenon is totally fainted... someone connected the network cable to two ports of the switch, short circuit .... after pulling out the network cable, re-connect the faulty port to the main switch to restore the network. finally, in the case of such problems, check the client for some additional vswitches. Generally, the switch in the active data center will not have the wrong wiring problem. First, check whether the client has any abnormal wiring, then, whether the primary switch is faulty.