News Center
Jiangsu Juntongling Science and Technology Co, Ltd
Network Expansion Failure Caused by Stale Cables
Release time:
2018-06-21
With the continuous popularization of network applications and the continuous expansion of the scale of the unit, many LAN networks that have been established for a long time have almost all the needs of upgrading and expansion. In order to save the cost of network upgrade as much as possible, many network administrators often make full use of some old equipment and old cables that are in normal working condition when expanding the network, so as to make the best use of everything. However, in the case of retaining old equipment and old cables, network expansion is prone to some unexpected failures. This is not, a network expansion failure listed below in this article is caused by retaining an old network cable, considering
With the continuous popularization of network applications and the continuous expansion of the scale of the unit, many LAN networks that have been established for a long time have almost all the needs of upgrading and expansion. In order to save the cost of network upgrade as much as possible, many network administrators often make full use of some old equipment and old cables that are in normal working condition when expanding the network, so as to make the best use of everything. However, in the case of retaining old equipment and old cables, network expansion is prone to some unexpected failures. This is not true. The failure of network expansion listed below in this article is caused by the retention of an old network cable. Considering that such detailed factors seldom occur at ordinary times, we will restore the detailed investigation process of the failure now. I hope everyone can take fewer detours when encountering the same failure phenomenon in the future!
Network expansion failure
My friend's unit has a small local area network. All the Internet hosts in the network are distributed on the 1st, 2nd and 3rd floors of the unit building. All these Internet hosts are connected to several ordinary switches located in the information center computer room on the first floor through ordinary twisted pairs. These switches are connected to the router equipment of the building network and interconnected with the superior units through router equipment. The 4th floor of the unit building is a conference room. When a meeting requires online demonstration, the network administrator specially reserves a network cable so that the computer used for online demonstration is directly connected to the ordinary switch in the central computer room through the network cable.
Recently, the internal reorganization of the unit building has transformed the original conference room on the 4th floor into ordinary office rooms. More than a dozen computers have been added to these office rooms, and they all have the need for Internet access. Considering that there is only one network interface on the 4th floor, the network administrator plans to use a 24-port ordinary switch to expand the Internet network on the 4th floor. In order to save trouble, the network administrator did not rewire, directly use the old network cable originally pulled to the conference room on the 4th floor to connect the newly bought 24 ordinary switches to ensure that the switches are directly connected to the router in the information center computer room. Considering that the newly bought 24-port ordinary switch has no management function, users can often plug in the network cable directly without any configuration. However, when the network administrator connected all the more than a dozen newly added computers on the 4th floor to the switch through network cables and randomly selected one computer for online testing, it was found that the network access was not successful. I thought this kind of network access failed, it is only a very rare phenomenon, but several computers have been replaced continuously and the network access test has been carried out. The test results are all network access failures. At the same time, the computers located on the 1st, 2nd and 3rd floors can access the Internet normally. It seems that the newly expanded 4th floor work network has not been correctly connected to the building network, that is to say, the 4th floor network has not been successfully expanded.
Track fault location
1. Check the switch status
Is it the quality of the newly bought 24 ordinary switches? But regardless of the quality, the newly bought equipment will not be able to be used normally as soon as it is bought back, right? The network administrator wondered for a period of time and was ready to test whether the working condition of the equipment was normal. First, he randomly selected two computers in the network on the 4th floor and conducted a shared access test among them. The results showed that the shared access operation was successful. Then he randomly used ping command to test the IP address of another computer in the network on the 4th floor. The returned result was normal, which proved that through the newly bought switch, the internal communication of the connected 4th floor network is normal, so it means that the working state of the newly bought switch is normal.
2. Check the UPLINK port
After excluding the quality factor of the new switch itself, the network administrator began to doubt the UPLINK port status of the switch, because the 4th floor network is connected to the ordinary switch located in the central computer room on the 1st floor through the UPLINK port of the new switch. if the UPLINK port is not working normally, then the 4th floor working network will definitely not be able to access the outside network through the router equipment of the unit LAN. In order to check whether there is any problem with the UPLINK port of the new switch, the network administrator specially moved the newly bought switch to the central computer room on the first floor, and found another network cable with good connectivity. The UPLINK port of the new switch was directly connected to the ordinary switch of the unit building network, and then a notebook computer with correct Internet access parameter settings was connected to the ordinary switch interface of the newly bought switch and tested on the Internet, the result of the test is that the notebook computer can normally access the network, which also shows that there is no problem with the UPLINK port of the newly bought switch, so the failure of the work network expansion on the 4th floor has nothing to do with the UPLINK port of the new switch.
3. Check the status of the old cable
Since the newly bought switch ordinary switch port and UPLINK port are working normally, what other factors will prevent the working network on the 4th floor from maintaining normal connection with the network of the information center? Considering that the new switch can be directly connected and used without setting up, this indirectly proves that the failure of the 4th floor work network expansion has nothing to do with the network configuration. So is the problem the old reserved network cable connecting the 1st floor network and the 4th floor network? The network administrator clearly remembered that at that time, for the convenience of drawing, he did not pull the cable to the 4th floor repeatedly, so he kept the old network cable used to connect the conference room computer. Could it be that the old network cable was damaged? In theory, the usage rate of the old network cable is not very high at ordinary times, and it will only be used occasionally during meetings. The network administrator thinks that the old network cable should not be damaged when no one touches it. In order to check whether the connectivity of this network cable is normal, the network administrator immediately found a cable tester to test the connectivity of this old cable, when the network administrator correctly inserted both ends of the old cable into the test instrument and tested it, he found that the signal lights of the test instrument flashed in turn, which means that the old cable did not have any problems in connectivity.
Key words:
Contact Us
Address: Hongqiao Industrial Park, Touqiao Town, Guangling District, Yangzhou City
Service Hotline:13801454277
Mobile:13801458637(Mr. Jiang)
Operator:0514-87265158
Telephone:0514-87267638 0514-87268261
E-mail:13901174762@126.com
Mobile website
Mobile website