Recently we noticed that the wifi in our office has just dropped to a crawl. Doing a speed check using our provider's own speed check tool (which would seemingly choose their closest server) the tool showed about 9 Mbps for download! We should be getting 200 Mbps. Then I directly connected to the same MK wifi and did the same speed check and the result was 101 Mbps. So what could be going on? Since this MK router is internal to our network, it has no firewall rules.
It is a CRS125-24G-1S-2HnD on 6.49.1.
Thanks for any input.

You don't say what you are using for the main wireless in the office, what your APs are and what bands you're using.

It does sound like the router's WiFi is separate, and if the router's WiFi gives much better results, it suggests the router may not be directly the cause of the slowdown.

What sort of speed are you getting for download on a wired connection?

By switching to Channel 8 the speed has dramatically improved to 49 Mbps download.

Spynappels: I listed in my original post the device in question, which is the wifi access point. I also indicated what download speed I'm getting with a wired connection.

Spynappels: I listed in my original post the device in question, which is the wifi access point. I also indicated what download speed I'm getting with a wired connection.

Sorry, it wasn't clear that the device was being used for all wifi and that for your second test you were wired as you specifically mentioned wifi for your second test.

Channel 8 is overlapping with both 6 and 11, on 2.4GHz you should only really use channels 1, 6 and 11 as all other channels overlap with one or more of these and will cause additional interference.

It sounds like the spectrum may be quite crowded and you might benefit from looking at APs in the 5GHz band which is generally less crowded, congested and less likely to have interference.

Yes. Indeed wifi can always become extremely slow, caused by many factors, some of these are static as the parameters set in the AP or client, some have to do with wall's and distance, but mostly it is dynamic, caused by other signals claiming a part of the available air-time (time where one device can transmit wifi in that channel), or interfering/destroying your transmission from an overlapping channel, or a non-wifi transmitter.

These topics might require some reading like : https://www.metageek.com/training/resou ... -slow.html to understand the most important causes of a slow wifi.

You did not share your config yet. So no advice on this is possible.
The config on it's own would not be enough to fully analyze your instance of a wifi problem.

Active scanning your RF environment is one of the steps that can also be done with the MT. This will indicate the best channel to use, and the potential issues with your wifi.

And then ...
- location, wall's and distance will change the signal strength and quality
- in the MT AP wireless registration table, with enough columns added, you can see the signal strength, signal-to-noise ratio, retransmits and signal quality (CCQ)
- the result is also there as the interface rate that is used for transmit and receive. There is normally 50% overhead for the user data rate.
- competition (co-channel interference, adjacent-channel interference, and non-wifi transmissions) can be seen with the built in MT tools (freq usage, freq scan)

However understanding the slowdown is not always easy.
- if in the same channel some device uses a low interface rate (e.g. 6Mbps) and transmits continously, then whatever your interface rate is, you will be as slow as that slow device
- co-channel interference travels 4 times wider in space than the usefull signal (it is not stopped by walls).
- RF communication to consider is all transmissions in that channel. This is not bound to your AP and clients only.