UniFi - Troubleshooting Client-Specific Connectivity Issues


Overview


This article will provide suggestions for troubleshooting and resolving issues with certain devices being unable to connect to Wi-Fi. 


Table of Contents


  1. Introduction
  2. Understanding Device Compatibility
  3. Tips/Suggestions
  4. Related Articles

Introduction


In some cases, users may encounter issues with certain client devices being unable to connect to Wi-Fi or have specific performance issues that appear to only coincide with certain segments of devices. For example: Android phones cannot connect to my UniFi network or iOS devices frequently disconnect on my network. These can be confusing and difficult issues to solve for network administrators especially since in many cases the root issue can be difficult to identify. 

To most quickly identify and resolve these issues, users need to identify the common threads/scope of the issue and use that to narrow down to a root cause. This article will explain how to approach issues like these and list some common causes. 


Understanding Device Compatibility


When a client device connects or fails to connect to a UniFi network, the process on the UniFi side is relatively simple and straightforward. This doesn't change for each individual type and variety of client. UniFi has millions of APs in deployment that work with all manner of client devices without issue. Additionally, UniFi does performance tests on hardware with a variety of client devices to ensure proper function. 

Outside of UniFi, there are many variables involved with all the different devices, network drivers, wireless adapters, etc. that often go unnoticed/aren't frequently considered. In most cases, issues assumed to be UniFi issues that are confined to a segment of client devices end up to be totally unrelated to UniFi. In some cases, you can change your UniFi configuration to help adapt your network to the limitations of your devices. For instance, fast roaming may not work well with all client devices depending on how old they are, how these products roam by default, etc.

When an issue like this occurs, it's important to narrow the issue down as much as possible to different client devices, software versions, etc. so that you know where to look for the solution. Here are some good questions to ask when encountering such issues: 

  • How many devices are affected?
  • What do these devices have in common? Location? Device hardware? OS version? 
  • When did the issue start occurring? 
  • Does it occur in all cases or is it intermittent? Is the issue consistently reproducible? 
  • Is there an error message? 

Many users mistakenly attribute any issue they encounter on a Wi-Fi network to the hardware connecting the devices or the internet service provider, using proper troubleshooting and not assuming a particular explanation will help you resolve issues as quickly as possible. 


Tips/Suggestions


Here are some suggestions for resolving client specific issues with Wi-Fi: 

  • Verify user-reported issues yourself- most often the cause for individual client Wi-Fi issues that are unreproducible by others is user error with WPA key entry or similar issues.
  • Make sure client has high signal strength and eliminate interference from the equation if at all possible. 
  • Reboot client devices first when a small number of individual client devices are affected.
  • Try updating wireless adapter drivers on client devices when a subset of devices with same wireless adapter are malfunctioning, or in individual cases. 
  • Once you've arrived at an understanding of what the behavior is and confirmed it, perform a web search for similar error messages/behaviors from similar client devices- if the device affects all Android devices for instance, you'll certainly find mention of in threads unrelated to UniFi. Follow steps and contact the device vendor for help. 
  • In individual cases where an issue proves difficult to resolve, scan the device for any malware that could be causing connectivity issues.
  • Try eliminating any advanced features like RADIUS or fast roaming from your UniFi Configuration to ensure that they haven't been improperly configured or that your devices do not support such configurations. Set up a parallel, simplified Wi-Fi network with as few modifications to default config as possible to see if issue is eliminated.
  • Use packet captures to monitor traffic to help identify root causes.
  • Search on community.ubnt.com for similar issues or post asking for suggestions.

When issues affect all devices, this implies that the issue is more likely to be a result of poor configuration or a potential performance issue on the UniFi side. If you encounter issues that are reproducible across all subsets of devices and appear to be related to UniFi and its function, please post on our community or contact UniFi support for additional help. 


Related Articles


UniFi - Troubleshooting Slow Wi-Fi Speeds

UniFi - Identifying Wi-Fi Issues with Debugging Metrics

UniFi - Troubleshooting Connectivity Issues

UniFi - AirTime: What's Eating your Wi-Fi Performance?


We're sorry to hear that!