NetworkTigers on troubleshooting your network safely.
The ability to troubleshoot your network is a skill that IT administrators need whenever an issue arises. Your troubleshooting procedure needs to be executable without causing damage to your network’s operations.
To troubleshoot a system effectively, you need to be as much a detective as a technician. Use the tips below to minimize risk to your network while troubleshooting and establish a foundational understanding of how to best approach a problem sensibly with minimal disruption.
1. Know the network
The most critical first step in your troubleshooting process is to have a detailed understanding of the affected network’s connections, configurations, firewalls, and software. Good network documentation comes into play here, as the ability to consult diagrams and notes for information related to IP addresses, traffic behavior, and access points is crucial.
2. Be cautious and methodical
Avoid making impulsive or risky changes to your network. Think and plan carefully. Look ahead to the possible outcomes of any changes you’re considering and prepare to address any consequences that may occur swiftly.
3. Take notes
Before you begin to troubleshoot, plan to take notes. Documenting each step of the process and what happens as a result helps you keep track of your method and allows you to go backward should something you do exacerbate the problem or create a new one.
4. Consult any affected users
When a user reports a problem, getting information from them is necessary. Ask them about the symptoms they have experienced and any error messages they may have received. Ask them when the problem occurred, what steps they took to produce it, and whether or not the issue affected other users similarly. Take note of any device configurations or settings they may have changed before the issue.
5. Always have a backup plan
Before modifying your network, implement robust backups to ensure you can return to any settings or configurations before your investigation. In cases where a change results in a more severe or difficult-to-diagnose issue, being able to revert to a more stable and functional foundation allows you to regroup and prevents prolonged network paralysis that may result from getting in over your head without a path out.
6. Check all physical connections
Sometimes, a network issue can result from something as basic as a loose cable or unstable connection. Inspect ethernet cables, power cables, and network ports to ensure no connections have been pulled out and no wire damage has occurred.
Cables can be damaged accidentally while moving equipment, from being pinched, or from chewing rodents.
7. Restart hardware devices
Don’t underestimate the power of a simple reboot. Once the affected device has been determined, restart it. In many cases, bugs or glitches can be solved by refreshing the hardware. Taking this basic step may be the only course of action required.
8. Update your devices
When a network contains outdated components, compatibility and communication issues can occur. Leaving software and firmware outdated also results in security lapses that lead to data exposure and cyberattack susceptibility.
As part of your troubleshooting process, check to see that the source of the issue is up to date. If not, download and install the latest drivers, firmware, software, etc. Restart the problem component and see if the bug has been resolved.
Set up automatic updates wherever allowed to ensure your system is as current as possible. If automatic updates are not an option for a particular device, schedule manual checkups in your calendar to keep up.
9. Test network connections
Run some basic network diagnostics on the device that is acting up. For example, you should use a ping command to test a specific IP address or domain’s connectivity. Traceroute/tracepath tools can inspect the path packets travel to their destinations, allowing you to identify bottlenecks or roadblocks that may impact performance.
The more tools you can employ to help hone in on where the problem occurs, the easier and faster applying a fix will be.
10. Confirm DNS settings
Misconfigured DNS (Domain Name System) settings can open a Pandora’s box of confusing and frustrating network issues. Carefully inspect all devices to ensure their settings are correct and have not been accidentally changed or meddled with so that communication is hindered.
11. Check for and resolve IP address conflicts
Communication issues are unavoidable if two devices on the same network use the same IP address. Use an IP scanning tool to locate duplicate IP addresses and change any repeated ones. Assign static IP addresses to your devices wherever applicable to prevent automatic IP address assignment conflicts.
12. Inspect network traffic
The insights gleaned from network monitoring tools are invaluable when it comes to preventing network issues, as well as troubleshooting them when they appear. Look for unusual patterns or behaviors that can help you locate parts of the network experiencing a problem.
Odd patterns could indicate everything from malware and misconfigurations to architecture misbehaving due to falling out of date.
13. Utilize online resources and official product documentation
Brand-new, never-before-seen network problems are rare. If you’re experiencing a mysterious bug, chances are that you aren’t the first.
Check in with online forums and IT communities to determine if someone out there can provide real-world insight into what might occur. Search for your problem specifically to see if it’s already been documented, and if not, reach out with posts on relevant sites to pick the brains of those with more experience.
You should also consult official support teams and product documentation for guidance.
Methodologies for troubleshooting your network
There are several troubleshooting strategies that IT professionals may employ when it comes to sussing out problems. While each methodology has pros and cons, savvy administrators will familiarize themselves with each to determine how to best approach their issue.
Below is a brief description of the three most popular troubleshooting methodologies:
Top-down troubleshooting uses the Open Systems Interconnection (OSI) model that technicians should be well versed in. The key concept of the OSI model states that each layer of a network’s operation relies on the layers beneath it to function. Using this principle, one can assume that if a layer works, the one below it is also in good health.
For example, if an application is experiencing a problem, the first step is to see if the issue is within that particular program on that layer. If the application is functioning as expected, the next layer is tested, and so on, all the way to the actual physical connection.
The bottom-up approach also takes advantage of the OSI model but does so in reverse. Physical connections are examined first, and then each layer above is tested in turn up to the application layer.
The pros and cons of a bottom-up approach compared to a top-down approach depend on where the problem exists, as using a bottom-up method only to find the issue in the application layer wastes as much time as using a top-down approach to locate a broken cable. Because of this, the method used depends on a technician’s intuition and ability to access the physical connections within the network easily.
For example, suppose connections are located in hard-to-reach locations that require time and effort to inspect manually. In that case, it might be in a tech’s best interest to start with a top-down approach and only deal with physical connections and cables if it comes down to it.
Divide and conquer
When executed correctly, this approach tends to take the least time. As opposed to starting at the top or bottom layer of the OSI model, divide and conquer begins somewhere in the middle. By making an educated guess about the location of the problem, an administrator can test network layers above and below their starting point to determine in which direction the root cause of the issue is and proceed accordingly.
This strategy results in fewer layers to test but requires extensive experience to know where to begin.