troubleshooting network problems

troubleshooting network problems

The successful troubleshooting of a network problem requires to follow a number of steps logically and methodically. It is better to follow the steps in order, though an expert troubleshooter might follow a different order or might skip one or more steps. The steps are:

1. Identify the Symptoms. When troubleshooting of a network problem, the first step is to identify the specific symptoms of the problem. It helps to closely pinpoint the problem. In a network, symptoms of a problem might include a user’s inability to access the file server. Accordingly, the problem might be related to a faulty NIC, a faulty cable, etc.

2. Verify User Competency. It is natural for a human to make mistakes. For example, a user may have typed the case sensitive password without considering the caps lock function is turned on and might get the message ”incorrect password” though the password has been entered correctly. Therefore, one of the first steps of a troubleshooter is to ensure that human error is not the source of the problem.

3. Identify the Scope of the Problem. The scope of the problem defines the affected user group for the problem or a particular period of time when the problem appears. For example, a problem might affect a certain group of users or a certain areas of an organization, or the problem might appear at a certain period of time. If a problem affects only users on one network segment, then the troubleshooter can concentrate only on that segment to find the real cause.

4. Recreate the Problem. An excellent way to learn more about a cause of a problem is to recreate the symptoms. If the symptoms cannot be created then the troubleshooter might suspect that it was a one-time problem. In contrast, if the symptoms can be recreated, then it could give the troubleshooter a clear understanding about the source of the problem. However, be careful not to recreate a problem that might cause physical damage of device or data of the network.

5. Verify Physical Connectivity. One of the most straight forward potential flaw in network communications is the physical connectivity of the network. Physical connectivity might include the cabling between devices, installation of devices, etc. Physical connectivity problems are easy to identify and easy to fix.

6. Verify Logical Connectivity. Logical connectivity problems are often very difficult to isolate and resolve than physical connectivity. A logical connectivity problem is associated with the software which might include resource conflict with the NIC configuration, an improperly configured NIC, network service, network protocol, etc.

7. Consider a Recent Change. Finally consider a recent change of the system related to the network, which might include introduction of new equipment, removal of equipment, installment of a new service, addressing or protocol changes. Such a change can create problem in the network.

8. Implement a Solution. After finding the problem, a solution can be implemented.

Network troubleshooting: An example

Perhaps one of the most common problem that a network troubleshooter faces is the inability of the user to connect to the network or simply unable to connect or access the network. This problem can be caused by a number reasons (hardware and software) and situations (user error or changes in the network infrastructure). The following set of initial information might help the troubleshooter to identify the problem.

1. The time when the problem begins.

2. The user is only experiencing the problem or other users have the same problem

3. The kind of error message that the user has received when the user tries to log on.

4. The connection of the network cable - whether it is accidentally pulled out.

5. Whether anyone has worked with any other devices of the computer, for example the sound card.

If the user answers all the above questions and mentions that someone actually worked with the sound card while all the other answers do not point to any problem. For example, the physical connection is perfect. Then the troubleshooter can guess that a configuration change might have caused the problem.

Tweet

Read More..