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.
When wireless connection problems occur, how end users and administrators respond depends on various factors. In this article, we consider 10 common steps for troubleshooting and exonerating the wireless network on the way to finding the source of trouble.
Step 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.
- 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.
Step 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.
Step 3: Sleuth 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 184.108.40.206. 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.
Step 4: Report trouble with good information.
Outside of the smallest business environments, a business WLAN typically has several components that help you get on the network and keep you connected. The fastest resolution will come with good information relayed to support staff, whether it's a formal help desk or just the IT person who deals with problems. The following information and questions are important when troubleshooting wireless connection problems:
- Where did the problem occur? Within a given room? If applicable, did the trouble follow you to a different room, floor or building?
- If you have multiple devices, did they all have problems? If not, which devices worked and which did not? If they all failed, did the failure feel the same?
- What time and date did the issue happen? Nothing is harder to troubleshoot than, "Last week sometime, I had an issue on the network." Every hour of network operation equals thousands of lines of logs to parse. Good timestamps help immensely.
- Get a meaningful description of what was experienced. Was the wireless network visible? Could you connect but get nowhere, or not connect at all?
- Did you get an IP address? Was any DNS testing done?
- If on a smartphone, did you toggle between Wi-Fi and cellular to see if one network behaved while the other did not?
- There's no such thing as too much information when reporting network troubles. Just try to be specific.
Step 5: Untangle advanced client issues.
When everything seems to be configured correctly, but a certain device just won't behave, it's time to dig deeper on the device. At this point, one classic mistake is to start adjusting settings on the network to try to "fix" a problematic client device. Leave the network alone or you'll likely cause bigger issues. Watch out for these following items, and expect all of these to be scrutinized if a help desk is involved:
- Unfortunately, drivers can still wreak havoc on whether a Windows machine will perform well on Wi-Fi. Even with Windows updates turned on, most hardware drivers do not automatically refresh. Check the drivers for your wireless adapter, basic I/O system, and chipset for freshness. All three can cause problems.
- If you are connecting to an enterprise secure WLAN, something as simple as time and date inaccuracies can prevent wireless authentication. Make sure yours are right.
- Enterprise secure networks are far more complicated than those simply using a password or pre-share key. Several settings may have to be configured and possibly even a certificate loaded on your client device before you can connect. Business networks are frequently concerned with authentication, strong encryption and logging details of every connection for audit and troubleshooting purposes. This greatly increases the complexity of getting individual client devices onboarded. See if your network administrators provide a configuration tool or written instructions on getting configured, or you'll likely stay dead in the water.
- User credentials can also be a problem -- especially if your network requires occasional changes to passwords. Make sure your Caps Lock is not on, and that you know your password before attempting to connect.
Step 6: Understand infrastructure failure points.
Most of the 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.
Step 7: Quantify application and destination issues.
What if you're successfully connected to 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.
Step 8: Squish code bugs.
Unfortunately, in today's business wireless networks -- despite high prices and promises of cutting-edge innovation -- the logic under the hood is often buggy. 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.
Step 9: Run a tight ship.
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.
Step 10: It 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 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.
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