How to Debug Networks

Network troubleshooting takes time and skill.

Network troubleshooting is part art and part science. Tools exist to help a network technician narrow down a problem, but knowing which tool to use in a given circumstance requires networking knowledge and a natural knack for solving difficult problems. Debugging a network can take time since network problems tend to be elusive, due to the many components on a network.

Instructions

1. Determine the exact symptoms of the problem. The first report of a network problem typically comes from a user who cannot do something. Figuring out what can and cannot be done is essential to solving the real problem. If the user cannot print, it may just be a printer problem. If they cannot log on, they may be using the wrong credentials. This can be a time-consuming step, but it is a necessary step that will likely save time in the long run. Eliminating other possibilities helps you to determine that the issue really is a network problem.

2. Identify the components involved in the problem. This may include a computer, a switch, a router, network wiring or some other component of the network connection in question. Check the network connection for each device involved to be sure it is connected to the network properly.

3. Eliminate as many devices as possible from the list of potential trouble-makers. For instance, if other devices connected to a switch have no problems, that piece of equipment is not likely to be the problem. This helps to narrow down your search for the culprit and reduces the trouble shooting timeline.

4. Test basic connectivity by using commands like ping and traceroute. Ping attempts to send a test packet to the destination device and waits for an answer. Traceroute does the same thing but adds a report of the various network hops (routers) to the output. This can help you determine whether there is a connection available and where it breaks down, narrowing your search down to a specific device or wiring segment.

5. If the problem is a wiring segment, replace the wiring. If the problem is a computer or other device, check its network configuration. If it is configured properly, there may be a hardware problem that requires you to replace the network card in the device or the entire device.

References

• Make Use of: 7 Simple Steps to Diagnose a Network Problem
• GHacks: Network Troubleshooting Basics – Some Simple Steps
• Practically Networked: Windows XP Network Troubleshooting
• Computer Hope: Basic Network Troubleshooting