【 Weak current College 】 wireless network loops into network access to the culprit

Unit A subnet network normally have been able to work properly, however I discovered recently A subnet workstations in the LAN Server not accessible units, after a careful examination, I see A subnet network new input using switch devices often connect the unit's core switch in LAN.

Taking into account the other subnet LAN workstations to function correctly, as this author believes that flat LAN core switch device is not present any problem, but A subnet network new input device is using the switch just unpack the equipment, the equipment appears the breakdown of possibilities is not very big, so I think is most likely A subnet new input switch equipment and units of local area network connection between the core switch fails. After careful investigation of the scene, I found A subnet of the new switch is using multi-mode fiber this media and LAN that is directly connected to the core switch, and use this medium to connect to a network connectivity failure occurs relatively small possibility that some; therefore I first thought of A subnet of the new switch would not have happened "soft" type of fault, the thought of this point, I restart a new switch device, wait until the device is restarted, the author attempted from A subnet to access LAN Server units resulted in the discovery of the symptom as usual. The author cannot be reconciled, and units of local area network core switch to restart it, and in the core switch startup process, the author carefully observed the switch status of the lights in the Control Panel, find the connection for A subnet that the new switch ports that lights blinking status for several seconds to immediately disconnect, a network connection line appears bad phenomenon?

No, I will again scepticism "sight" to the physical circuit connecting the media; because here is using the connection medium, fiber optic cable to the author by excluding method then click on fiber adapters, fibre splicing head ends, as well as fiber-optic trunk cable jumpers, and other factors by troubleshooting test, the results did not find any suspicious behavior, just for the above troubleshooting test, occasionally see A subnet new switches and LAN connectivity between core switches, but after a few seconds and immediately disconnected.

There may be A subnet of the new switch is not properly set up work parameters? considering this factor, I immediately pressed A subnet new switch control panel restore button, the device parameters all return to the default factory values, then the proper way to reset the network parameters, and perform the save operation and restart at A subnet of the new switch device. Thought this new switch resets, network access to the fault can be automatically eliminated, but when I once again from A subnet of a workstation to attempt to access LAN Server, the unit I found A subnet is still not able to properly access unit LAN Server.

In despair, I happened to see A subnet of the new switch has a fibre optic jumper as if there is a problem, so I stuck to this root jumper pulled down, while carefully observed the new switch control panel lights work status, found and local area network core switch that is directly connected to the port State should correspond to the work resumed, this time try from A subnet to access LAN Server units, network access has been properly. In order to confirm A subnet workstation cannot access unit LAN server failure whether it is from this root jumper, I again will it reconnects to A subnet of the new switch and found as long as connected to this root jumper, the new switch control panel Link port light is in rapid blinking status, not for a few seconds, the corresponding port lights are automatically turned off, at which point we will find A subnet workstation will not be able to access LAN Server units.

According to the above symptoms, I unhesitatingly believe this jumper is sins of a network failure, so the author named Samuel began to look closely at this root jumper and the jumper is connected to the network device. As a result, I see this fiber jumpers and another switch Gigabit module is connected to; take a look at another switch, the author has seen two wireless AP device while connected to the switch device, both the wireless access point equipment in any server moved, A subnet workstation immediately can properly access LAN Server units. It is obvious that the fault caused the network access to the real cause is actually the two wireless access point devices.

After further investigation, I see the two wireless AP mode in accordance with the principle of the device should be set to work mode, but the AccessPoint not know how it happened, I find a wireless access point devices work mode has been modified to work in mode AccessPointClient. In that case, and the same switch devices directly connected to both wireless AP device imperceptibly and formed the wireless bridge network, the network has led to A subnet in network loops, it is this network loops caused A subnet workstations in the LAN Server not accessible units.

Small Tip:

Through the above failures, it is not difficult to find the network wiring is how important. From the face of it, network wiring seems very simple, in fact, it is very advanced, practical, confidentiality, security, and reliability, it is a systems engineering. Only the network cabling with the full understanding that can lead to sufficient attention to the actual wiring process are willing to invest, so that the network cable layout more systems, specifications and reasonable. Only the system and network cabling to ensure communication network of flexible extensibility and subsequent smooth upgrade, you can greatly reduce the workload of network maintenance in the future, in particular to a significant reduction in continuous investment in network maintenance costs. Network cabling is for the entire communication network system build a transmission performance goodNetwork platform, the use of the network platform, ensure that the entire communication network system has a certain maturity, flexibility, openness, interoperability, security, as well as a very good price-performance, for example, on the whole floor or whole buildings system wiring, as long as reasonable planning, allocation of staff resources, the network traffic maintenance costs reduced to the original half.

On the network cable to the system layout, you can use of common standards for cross edge system, to easily and quickly on a network device layout, installation, testing, debugging, thereby making networking units on the network-building investment to obtain ideal efficiency. Through a systematic and structured manner, network cabling, network form a diversified features star physical structure that can apply to almost all kinds of different topology requirements to guarantee the formation of a good network has a wide range of applicability. Because this kind of network structure, easy maintenance and extended upgrade, just some of the network node, with some local variations, almost without moving any cable and equipment.

In addition, in the planning layout, you should follow the principles of progressiveness and practicality to; network wiring in the various technologies involved, should adopt open standards to ensure that your network system facilitate interconnection and extended; of course, in order to guarantee the future of good scalability, we should also use the routing process, selection of standardized design of the standardization of network equipment and products; in order to ensure that the network of serviceability, network wiring in our planning, we should try to use modular design principle, take full account of the hierarchical network maintenance, visualization, ensure that network maintenance simple and easy.