Easy solution to LAN failure with network test tools

Network failures are unavoidable, and it is important to isolate and troubleshoot them quickly. Network maintenance personnel should be equipped with appropriate tools and corresponding knowledge, in order to timely and effective to find and solve problems. This article discusses ten vexing problems that network technicians and engineers often encounter. Analyze the problem first, and then discuss what tools are used to help find and isolate the fault.

1. Arresting the abusers of the physical layer

User complains: Unable to log on or off time.

Symptom (s): Only one workstation is affected, and the station has no previous problems.

To find the problem:

The cable terminal link is too long. Users move, bend, connect and Disconnect network terminals (especially laptops) on a daily basis. A cheap cable tester can check the problem. Before you can say exactly what a cable is, it is usually the first consideration that is not a cable problem. This requires the use of network test tools to prove the health of the local network segment is good, the hub port function is normal, network card and its driver is working well. Finally, check to see if there is a problem with the network Interconnect device. Only then will you know where to start testing the cables to isolate problematic terminals, disconnected connectors, or grounding loops. In the copper axis network, search in the same axis "T-head" and the end of the network card, in the UTP Network, continuous operation of the instrument diagram testing function, constantly twisting the terminal to identify contact with bad or short circuit.

Solve the problem:

Replace the workstation connection cable, replace the damaged connector, or stop using the horizontal cable if necessary. Thoroughly check the processed cables again.

2, Fast Ethernet is slower than the Ethernet before the upgrade

User complains: 10Mbps Ethernet speed is slow, upgrade to 100Mbps Fast Ethernet can not even connect to the Internet after.

Symptom (s): affects the new workstation or upgraded workstation connection to the Internet.

To find the problem:

For UTP5-type unshielded twisted pair, the cable tester is used to test whether it meets the Eia/tia TSB67 standard corresponding to the 100Mbps transmission rate. Some cable links that work well on 10Mbps Ethernet do not work because of the near-end crosstalk being too large for 100Mbps Ethernet. The signal is coupled to the adjacent line to cause high frequency signal transmission failure. Separating the UTP from the line will even paralyze the network when it reaches a certain amount of traffic.

Solve the problem:

Replace or deactivate a link that cannot be connected, and then all test the disposed link after the failure clears.