Tips for troubleshooting intermittent wifi drops

I was hoping someone could give me tips on troubleshooting an issue I am having with WiFi at a school I provide IT support to.

The reported problem is that every now and again devices drop from the wifi (which is a Ubiquiti UAP-AC-HD). Is anyone aware of any low cost wireless scanning tools that I can use?

My hope is to set up a laptop to graph wireless signal strength and noise to see if there is something drastically increasing interference or something like that which causes the drop.

I am just not familiar with any tools to do this.

Not familiar with tools to advise. But I have seen this with Ubiquity before.

I bet that someone configured the Ubiquity network to drop clients with low signal. This is supposed to force them to switch to a better AP in the mesh.

But what happens if there is no better AP available? Then it just drops clients for no good reason.

You may want to look around in the settings to see if you can turn off that feature on APs which are on the edges of the network where no other AP is available to take over a connection. Or add more APs to the affected areas.

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Thank you for the tip. I will check that out.

Is the AP connected to a controller? Can you look up why the clients are disassociating? Try running the RF scanner built into the controller to see if the channels the AP is using are busy.

If nothing stands out, what you’ll want to get is something called a spectrum analyzer. You’ll just chase your tail if you download apps that just report other SSIDs it can hear. You need something that can tell you everything that is talking around the 2.4Ghz and 5Ghz ranges. There can be devices out there that are talking in the 2.4/5Ghz range but are not any official Wifi standards. Those will cause tons of problems and you’ll never see them if you just get an SSID viewer.

Also, @zlynx is probably referring to either RSSI or ‘Minimum Data Rates’. First, don’t touch your RSSI values, it’s not good to kick clients off via their RSSI values. If someone has modified them from the default, set them back to the defaults. The better way is to control it via minimum data rates, which is where you define the minimum data rate a client is allowed to transfer data at. Like for example, you may configure your 2.4Ghz wifi such that only a device that can transfer at least 12 Mbps can be allowed to connect. This improves the overall speed of the wifi, but it will kick devices off that can’t talk at the minimum data rate because they are far away at or have bad signal to noise. If someone has configured up minimum data rates, I’d leave how it is unless they configured it to be higher than 12Mbps or unless you’re trying to cover a large area with a single AP and don’t care about speeds.