Wireless Network Diagnostic Simple Fixes

When troubleshooting wireless network issues, several scenarios can emerge.

Wireless networking is both pervasive and getting more complicated behind the scenes. For end users, Wi-Fi is the invisible network resource that they connect to. For wireless network administrators — who design, deploy and support the wireless LAN — the Wi-Fi network is a fairly complicated beast with many moving pieces that are part of the bigger networking environment.

Of all the types of computer problems you can have, network issues are one of the worst. Though our computers can do a lot offline, being cut off from the internet isn’t fun. Even worse, when you can’t get online, it’s not easy to research fixes for your problem.

Let’s step through the basic process of how to troubleshoot network connectivity problems. That way, next time you open up your web browser to a “Cannot Connect” message, you’ll know what to do. Like all troubleshooting, we’ll start broadly and narrow down to specifics.

After each step, attempt to connect to a website to verify your connection is working. If it still doesn’t work, continue to the next part.

Make Sure It’s Actually Your Network Problem

Sometimes what seems like a network outage is actually a problem on a specific website’s end. If you can’t get on Twitter, for instance, check another few websites to make sure that the problem isn’t just with a single site.

You can use  Is it down or just me to easily check if a website is down for everyone or just you.

1. Turn it on and point it in the right direction

Sometimes the most obvious causes of system trouble can be the hardest to see. All of us make faulty assumptions at times. When we go to access the Wi-Fi network and nothing happens, it’s best to start with the absolute basics.

Reboot your PC, as well as your modem and router. To clear the modem and router caches, wait 60 seconds before you turn them back on again. When you plug everything back in, plug your modem in first and wait for it to power on before connecting your router.

Turning everything off and back on first ensures that it isn’t a temporary network problem. It’s better to reboot now than to waste 30 minutes continuing on when you don’t need to.

Once you’ve restarted, if you have another computer (or a mobile device), try getting online with that machine. If you find that no devices can connect, it’s likely an issue with your equipment or your ISP.

Should you find that only one computer can’t get online, you can continue to narrow down the problem. On that device, make sure to run an antivirus scan to ensure you don’t have malware interfering with your connection. You should also make sure that your firewall settings aren’t blocking the connection.

Finally, try using a different browser to see if your usual one is somehow damaged.

• Regardless of what device you are using, verify that the wireless adapter is toggled on.
• On phones and tablets, make sure you are not in Airplane Mode.
• Many WLAN environments have multiple service set identifiers, or network names, and not all of them lead to where you want to go. When your Wi-Fi is enabled and you show a connection but can’t get anywhere, check to make sure you are connected to the right network for your particular role. Some wireless networks are special-purpose dead ends that don’t reach the internet.
• Depending on what network you are connecting to, you may need coordinated permission to use the Wi-Fi. If you skip this step, the wireless network can certainly feel broken.

 2. Define the scale of the problem

The vast majority of Wi-Fi problems are single-client issues — as long as the network was designed and installed by qualified professionals. At the same time, even market-leading vendors can deliver buggy code, and good components occasionally do fail.

When you encounter wireless network performance issues, you need to understand how far the problem stretches. This step applies whether you run the network, or just use it.

• Take a deep breath before you start calling the entire wireless environment bad. If you are the only one having wireless connection problems in a room full of people, then that is telling.
• Do you have a comparative device? For instance, can you connect with your laptop but not your smartphone? Can you compare your situation with someone nearby?
• If you conclude the issue is with a single device, user or password, then you may need help desk assistance to get configured correctly.
• All client devices and individual user accounts can have issues. Whether you’re a C-level employee or your device is a top-end Apple product, everyone eventually experiences wireless connection problems.
• If multiple users are having issues, the more details you can provide to IT, the faster the resolution will be.

3. Check Wireless Network Physical Connections

Does your network problem persist after rebooting? Before you start diving into settings and tests, the next step to check is that you’re physically connected.

If you use an Ethernet cable to connect to your router, check to make sure that it’s not unplugged or damaged. If your laptop has a physical wireless switch, make sure that it’s not set to the off position.

Once you’ve verified a proper connection, check your equipment. Are the lights on your router and/or modem flashing green as normal? If no lights come on after the reboot, the device could be dead or malfunctioning. However, if you get red lights, or a power light but no connection light, your ISP is likely experiencing disruption.

4. Investigate basic diagnostics

When your wireless connection fails, it can be unnerving, especially when you’re trying to do actual work. Laptops, tablets and smartphones can show and tell you basic diagnostic information. But you have to know what you’re looking at. Don’t jump to conclusions based on scant information.

• Signal bars are perhaps the most basic and universal indicator of signal strength. When wireless network connectivity is in question, we probably all take a look at the bars. If the bars are not present or too weak, then that’s good information — but it may not tell the whole story.
• Some client devices are really poor at roaming, which is the process of leaving one cell for a stronger or better one. Roaming is mostly all client-controlled, subject to however the wireless adapter driver code was written. This is not spelled out in the 11 standard, so vendors have flexibility to put their own spin on roaming. If my device doesn’t roam well, my weak signal can actually be poor device performance on a perfectly healthy network.
• Ping with caution. One of the most universal network troubleshooting steps is to ping a destination. This tells you whether the target device is alive, that the network path between source and destination is good in both directions, and how long it took to get a response. But ping may fail for several reasons — from host-based firewall settings to filtering along the way. Use ping, but know that it’s not absolute.
• DNS problems can be tricky. I try to reach SearchNetworking.com and it fails. Is the Wi-Fi broken? Maybe not. DNS translates the SearchNetworking server name to and from its IP address 206.19.49.153. If I put the IP address in the browser and get to the site, we have a DNS issue. Basic DNS tests are easy, and they tell a lot when troubleshooting. Include your DNS findings in any trouble ticket.
• Most well-run networks have everything labeled in some fashion. If you are reporting trouble and have an access point (AP) within sight, try to note how it’s labeled and what color LEDs are visible on it. Every bit of input helps for troubleshooting wireless connection problems.

Windows includes some built-in troubleshooters that can automatically find and fix issues. To run the troubleshooter for network problems, right-click the network icon in your System Tray and choose Troubleshoot Problems. Once the troubleshooter runs, it could fix issues, find issues but fail to fix them, or find nothing.

If the troubleshooter finds a problem that it fixes, try to connect again. If you get a specific error or problem name that Windows can’t fix automatically, take note of it for later research.

Advanced users might also look at using other tools to troubleshoot network issues such as SpeedTest.

5. Check for a Valid IP Address

At this point, you’ve verified that the problem is not temporary and that all your hardware works. Since Windows can’t fix the problem on its own, we need to pinpoint the spot along the connection where the problem is occurring.

It’s a good idea to make sure that you don’t have any strange IP settings selected. To check this, open Settings and go to Network & Internet > Status. Below the Change your network settings header, choose Change adapter options. In the resulting window, double-click the name of your network.

Next, you’ll see a status box. Click the Properties button.

Here, double-click the Internet Protocol Version 4 entry.

Unless you’ve set up a static IP (if you don’t know what this is, you probably don’t use one), make sure you have both Obtain an IP address automatically and Obtain DNS server address automatically checked. Repeat this process for Internet Protocol Version 6 to ensure everything is automatic there, as well.

Reviewing Your IP Address Validity

Once you’ve done this, you can check to confirm the router is giving you a valid IP address. Open up a Command Prompt window by typing cmd into the Start Menu. Enter ipconfig and look for the text under Ethernet adapter (for wired connections) or Wireless LAN Adapter (for wireless connections).

If IPv4 Address starts with 169.x.x.x, your computer is not receiving a valid IP address from your router. Typing the following two commands will release your computer’s current IP address and request a new one, which may resolve this:

ipconfig /release 
ipconfig /renew

Should you still have a 169.x.x.x address after typing the above commands and ipconfig again, your machine still isn’t receiving an IP from the router. Try plugging your PC directly into the modem with an Ethernet cable and see if you can get online. If so, your router is the problem.

6. Try a Ping and Trace Its Route

If your IP address starts with anything other than 169 when you run ipconfig, you have a valid IP address from your router. At this point, you’ve confirmed the problem is somewhere between your router and the internet.

Type this command to ping Google’s DNS servers to see if you can get online (you can replace 8.8.8.8 with anything, such as www.msn.com):

ping 8.8.8.8

This will send four packets to Google. If they fail to send, you’ll see some basic info about the failure. In case you want to continue pinging indefinitely so you can monitor it while troubleshooting, just add a -t to the end, like so:

ping 8.8.8.8 -t

You can press Ctrl + C to stop pinging at any time. For more information, type this command to trace the route between your computer and Google’s DNS servers:

tracert 8.8.8.8

The above command gives you a step-by-step breakdown of the path the information takes to reach the destination you specify. Watch it, and if it fails, check to see where the problem occurs. If an error pops up early in the route, the issue is likely with your local network.

7. Understand infrastructure failure points

Most of the wireless network WLAN infrastructure will be a mystery to the actual Wi-Fi clients, but there is value in understanding some common high-level failure points on the infrastructure side. In well-administered network environments, most of the following should be monitored closely with various automated tools. As mentioned earlier, most Wi-Fi problems tend to be single-user in nature, but those mentioned here will generally be felt by multiple clients.

• Wireless access points stop working for various reasons. They may experience component failure, firmware corruption or physical damage. Perhaps the cable connecting the AP to its network switch gets compromised, or the upstream switch port has issues. In a perfect world, there will be redundancy among access points and losing one isn’t noticed by end users. But not all environments are perfect.
• If a wireless environment is under-built, access points may get overwhelmed by high client counts or just a few clients doing high-bandwidth applications. Either way, if you are on a congested access point, it can be slow or unusable.
• If a switch that powers multiple access points has problems, then the chance of an area-wide or building-wide outage becomes very likely.
• Many access points are akin to business telephones because they get their intelligence from a network-connected component called a controller. When a controller fails, you may lose dozens, hundreds or even thousands of access points — this is every engineer’s nightmare.

8. Quantify application and destination issues

What if you’re successfully connected to a wireless networks Wi-Fi but can’t get a specific application to work? Or you try to reach a web destination, but you get an error page? Usually, these situations have nothing to do with Wi-Fi. Generally, other network conditions are to blame.

When you hit a roadblock, try to quantify what is working right and what is failing. Problems this specific will only be the fault of the WLAN if some specific protocol or destination is blocked in a firewall setting. The access points and actual radio frequency environment will have nothing to do with this sort of situation, but the information you gather will help administrators troubleshoot what’s going on.

9. Squash any code bugs

Several modern AI-driven analytics dashboards are available, but none of them can tell you that code bugs are hitting your Wi-Fi environment. So, we live with this problem, and surprisingly market-leading systems can be the worst offenders.

Although network administrators are responsible for resolving code bugs, end users often feel the effects. Whether in the form of a memory leak or an intermittent malfunction, code bugs can be the absolute worst thing to hit a wireless network. Here are some of the symptoms of code bugs:

• spontaneous reboot of multiple access points, from a few to thousands;
• APs that stop allowing client access;
• specific features stop working;
• some common subset of client devices all have the same issue while others are fine; and
• erratic network behavior for Wi-Fi clients or access points.

Code bugs often require a support ticket to be opened with the WLAN vendor. There can be a great deal of tension here. The network engineering team wants a fast resolution. Network users are affected, and organizational tech execs are looking for accountability while the vendor grapples with a convoluted troubleshooting algorithm.

Meanwhile, features may be disabled, but the end result is usually a code upgrade. When dealing with code bugs, communicate with users and upper management. Tell them what is happening: The network itself is fine, but the code running it is problematic.

10. Get organized from within

Today’s wireless networks are often extremely complicated and integrated with a growing number of parts of the larger network environment. Tools, training, documentation and monitoring are all key components as an effective response when trouble hits. The team supporting your wireless environments should have wireless-specific skills and the right software and test equipment to cut through the fog when responding to problems.

Good network diagrams, well-labeled cables, access points, switches and up-to-date call lists can reduce the time it takes to resolve problems. Staff needs occasional training and your tools will need to be refreshed periodically. It takes time to label everything and keep the diagrams accurate. But all of this is an investment at troubleshooting time.

11. Wireless Network works at home but not at work

Never before has there been such an amazing breadth of wireless client devices. From smart home gadgetry to wireless printers to Wi-Fi-enabled lab instrumentation, there is a fascinating array of stuff that wants to find its way to the business WLAN environment.

But there are also very real gaps between what the big expensive corporate Wi-Fi network can support versus your home wireless router. Many devices that we love at home just don’t fit well at work for a number of reasons:

• Lack of enterprise security features. Wireless printers and projectors are notorious for lacking 802.1X support, which relegates them to perpetual one-off status in many corporate Wi-Fi environments.
• Oddball requirements. Devices like Chromecast and several Apple products lack enterprise security support and require living-room style multicasting and discovery mechanisms that don’t lend themselves to working in larger, more complex environments.

• Competing infrastructure. Some client devices come with their own Wi-Fi access point that is required to form whatever system is in play. These poorly conceived components — lighting controllers, for example — interfere with the business Wi-Fi network, lack security controls and frequently imperil the LAN to which they connect.
• Incompatible data rates. At home, it’s common to try to stretch the signal from a wireless router as far as it can go. This is done with high power and low data rates that enable cells to stretch farther with lower performance at the edges. Some client devices require those low data rates, but it’s common to disable these slower rates and shrink the cells at work where capacity is more important than simple coverage.

In spite of all these wireless network connection problems, most well-run IT groups have an established WLAN policy that guides security, ensures performance baselines and keeps users from going rogue with incompatible hardware brought into the workplace.

Wanted to learn more about Networking? This article explains Network Protocols and this one on Network Security.

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