News of a group that suffered huge losses of unprovoked anger of shareholders who gathered in the business of the ICC in front of the room, asked why the dynamic real-time trading information display screen a large gap in the data set and the speed of transactions are Jiman, and Frequent disruptions, simply can not carry out transactions. If not immediately threatened to resume trading, the computer will Zadiao Stock Exchange. Retail business hall of the engine room also began to gather, if not promptly dealt with, emotional investors who may really be the business of the ICC network equipment smashed a dilute Palestinian Black. The network's users are 10 M Ethernet links, for 730 users. The trading system from satellite radio receivers on the way data transmission to the market, investors and trading information back to the trading center. From satellite receivers to monitor the observation of mouth, to receive the data completely normal, the network management staff preliminary determination is the Corporation's business network system problems. In fact, this failure phenomenon has already begun two months ago, when there is transmission of data error in the phenomenon, and sometimes the market data updates appear blank, and sometimes updated data rate will slow down occasionally and sometimes there will be intermittent phenomenon of the updated data . Although a detailed examination done, and with network management systems and protocol analyzer for monitoring and analysis, but such "symptoms" is not continuous emergence of the Internet and the speed and investors did not affect the basic transactions, it has not been found, The real cause of the malfunction. Management staff have been feel lucky, try to have the opening of a backup server and the replacement of some switches, hubs, but did not solve the problem. The day before yesterday participated in the "second round of the Securities unified system Y2K certification test", passed smoothly. Use the remainder of network management personnel conducted an inspection of the system and some hardware devices were detected and maintenance. After the restoration of systems, networking check. Normal network performance. Unexpectedly, the market opened today on a serious problem.

     F683-use network test any anti-access network ports, monitoring networks and 30 seconds, to observe the corresponding network traffic was 81%. Monitoring ports and some other links, also found that 81 percent of (the corresponding network management port 0.2 percent), the wrong frame 97.6 percent. The type of error for the Ghosts (accounting for 93%), FCS error (also known as the CRC error) and Jabber, that phantom interference, frame check errors and long frame, indicating that the network is A large number of illegal data packets exist. Stop the server and user transactions, monitoring has not changed the basic data on the wrong frame of data sources and application of basic network equipment or not. Suspected members of the network is a "trouble" the possibility of network attacks should not, because there are not so uniform and a huge number of error frames, because otherwise the relationship will switch its door. Such symptoms generally to electromagnetic interference and ground loop aspects of the majority, do not interfere with access through the Internet link into the channel, but from the ground loop of string to the network access equipment for each port. In order to determine the exact of interference sources, most of the hubs and workstations connected to the power shutdown group, servers continue to work to observe the error rate reduced to 87 percent, remains high. Re-open the Hub Power Group, with F43 harmonic power tester observation, found serious harmonic content (up to 1970 mV). The network with a large UPS power supply to all network equipment, harmonic analysis Power Measurement UPS input supply harmonics, harmonic content of the power output of about 30 percent, significantly lower than the output target, the power to determine " Within the harmonic "in the 646-391 exam resources, Cisco Lifecycle Services Express(LCSE), you will cover every field and category in Others helping to ready you for your successful Cisco Certification.
 UPS started small-scale replacement of spare parts of the network servers and other equipment, particularly the main power supply equipment, network immediately resume normal work (to reduce the load, the network equipment used in batches rotation access methods). However, continue to use the network test-observation network, the results still show that there are errors, the error rate (phantom interference) dropped to 1.3 percent. Hub Group once again off switches and other network equipment and power supply, the type of "Ghosts" (phantom interference) error rate dropped to 0.8 percent, confirmed that there are still strings to the circuit by grounding the illusion interference, and should be from the main channel To enter. Sub-examination of the master data access equipment and parts, satellite receivers shaken when the data output cable, the illusion that sometimes without interference. Remove the cables, jamming disappear. Management personnel thus preserving memories of the day before the machines had been fixed cables, which may cause undesirable or core-line connection with the shield "may wish to non-access." To enable investors to continue trading, their emotional stability, the replacement of cables and then the original UPS started to work to provide services. After the close of the replacement of large UPS, fault completely ruled out.