Original Google WiFi limits number of connections

[MarkMcough]

I have a Gen 1 Google WiFi network that I have had up and running for a long time - multiple years.

My architecture is  FiberOptic Router (500 Mb up/down) connects to Google WiFi via Ethernet cable.  Then the Google WiFi connects to my Network switch (48 port 1Gb speed).  My other three Google devices are then connected to the Network switch.  My entire house is wired with Cat 6 Ethernet, so many of my devices (TVs / DVD Players / Stereo / etc.) are connected via Ethernet cable, and not using the WiFi network.  I have two WiFi networks set up - my home use network, and my guest network.  I have installed smart switches / light bulbs extensively in the house - to the point that when I say "Hey Google, turn off everything" - it responds with "turning off 42 devices".  So total, between wireless automation devices (light switches / light bulbs / smart plugs / Android tablets) and Google access devices (Mini's, a Max, three displays) - there are a lot of connected devices in my house.  Starting this last week - I can no longer add a new device to my home use WiFi network - connection fails every time - but I can add that same device to my guest network.  Have run into the problem with my Traeger WiFi grill, a Kasa smart switch for the Garage lights, and a SofaBaton X1 hub.  In all three cases, I can add the device to my Guest network, and it works.  It appears that I have run into a connection limit - but everything I read online says I can support up to 100 connected devices - and I have not reached that number (I am around 73 total connections - wired and wireless - if my count is correct).  I have set my DHCP pool to allow 160 connections - so that shouldn't be the issue.  Any ideas on how to solve this - I really don't want to reconfigure my entire network.

[MichaelP]

Hello @MarkMcough 

Is there any chance some of your devices use dynamic MAC addresses? This is becoming more common, especially for cell phones and tablets, but may also include Windows PCs. The issue with this is, every time a device starts using a new MAC address, it has to get a new IP address assignment via DHCP. It may not release the previous IP address assignment explicitly before getting a new one. Since DHCP leases may be 24 hours, even a handful of devices using dynamic MAC addresses could exhaust a DHCP pool if they aren't releasing explicitly or are getting new leases frequently. So, I would first try expanding the DHCP pool as an experiment. You should be able to get up to 250 or so without changing the netmask.

That's the IP level issue I can think of. I don't know if there's a hard limit on total connected WiFi clients, though. Often, those limits are based on an assumed traffic rate rather than an actual hard limit, but it sounds like you're below 100 anyway, so that's not likely the issue (unless there's a similar issue with dynamic MAC addresses making it look to the WiFi layer like a lot more than 73 devices).

You might also just look at the list of connected clients and scroll down to the offline devices. If you see a lot of Unnamed offline devices, that may be an indicator that you have some devices using dynamic MAC addresses. Expanding the DHCP pool from 160 to 250 may not be enough, but if that helps, you can think about expanding the netmask to support hundreds or even thousands of address assignments.