Devices randomly disconnecting

[snakehollywood]

We are having a recurring problem with a few devices that keep randomly disconnecting/reconnecting from the wi fi continuously, or just disconnect and won't reconnect, saying that authentication failed.

Rebooting devices usually doesn't work.

Forgetting the connection and logging in again doesn't work.

Sometimes if we reboot everything, forgeto everything, reset network settings etc etc, it might work again, but usually not, and we just have to wait, which may take days or when weeks till it works again 

This only affects a small number off devices, my wife and daughter's phones and 2 fire TV's.

They all have a strong WiFi signal as we have a mesh network using the BT Discs.

We have had the router replaced several times and got new discs.

I have check the channel we are on, and it is not congested and interference from neighbours is minimal.

We have had numerous BT engineers out, but they are useless and have no idea how to actually troubleshoot the issue. All they do is come and check the broadband and WiFi is working, and just say everything is fine.

[Keith_Beddoe]

@snakehollywood 

Have you tried a factory reset of the BT Home Hub?

https://www.bt.com/help/broadband/how-do-i-reset-my-bt-hub-to-its-factory-settings

Connection issues can be caused by the home hub running out of internal connections. A normal restart does not fix that.

Its more of a problem if any of your devices are configured for MAC randomisation (sometimes called private addressing), as that can cause multiple unused allocations for the same device.

Change them to device MAC address.

A normal restart does not clear these entries, only a factory reset does that.

If you have BT Digital Voice and are using any of the BT supplied phones, make sure you backup the phone numbers from the home hub, before you do a factory reset. You can restore them afterwards.

[snakehollywood]

Hi,

Three Mac randomisation only applies to phones, nothing else does it, and I have disabled that on all the phones as I have a firewalla and use this for security be and parental controls, so devices with mac randomisation get blocked.

Is there any way to see the routers current allocations? So you know what the limit is?

[Keith_Beddoe]

Windows 10 and 11 also have MAC randomisation.

The home hub device list would normally show what is connected. Anything showing "unknown device" has most likely got a random MAC address.

Try the factory reset, as that will clear out all DHCP leases. Then see if you still get the problem.

You could also try disabling the 5GHz wireless band, provided that nothing needs it. Many dual band devices keep trying to switch between the bands, causing disconnections.

[Davosi]

Hi! 

im also experiencing this issue with my WiFi devices. We have WiFi radiators and they keep disconnecting and turning on by them selves because of this.

Since the beginning of December this has been happening. I also play games online and this has been impossible due to high intermittent ping spikes. 

we have had 4 engineers out, all of which were useless. 

all these issues occurred when my digital voice service was turned on, could just be a coincidence but my connection has been fine for 3 years until this. 

[snakehollywood]

The total number of registered devices is more than 30, which I can see on my firewall, however, these are not concurrently connected at all time, as many are my kids friends when they visit, or devices which are not always on.
Active devices is usually < 30

So does the BT home hub only count active devices or total number of devices that ever connected? 

It seems this is going to be an ongoing issue, so if factory resetting the router is the only solution, I would be doing this on a weekly basis, which is not an acceptable solution.

I assume the only solution to this is to get a better 3rd part mesh network?

[Mickyboy06]

following as this is similar to my issue (posted). random DC's and very poor wifi speeds, switching between 2.4/5ghz..... kids and wife going mad at me to fix it!  Not even going to waste my time on a BT engineer anymore. I've got max. speed to the SH2 and wired is all good.

[snakehollywood]

yes it seems not one single person at BT support or any of their own engineers knew about this limitation on their own routers. Its pretty disgraceful that I had to find out on this forum.

and if I buy myself a better router, they then won;t provide any support if I have any broadband issues because it's not a BT router, so I can;t win.

[countrypaul]

Have you read this: Smart Hub 2 Connectivity and Too Many Smart Device... - BT Community

Following his approach at least you can keep the SH2 (and therefore BT router support) but use a 3rd party mesh system for all the WiFi (as you seem to have suggested yourself). Not ideal, but may give you an option.

[Mickyboy06]

Thanks, yes I've just had a read. Sounds very similar with the key point coming out is the instability we are getting.

As said, the wired connections to our devices are full speed, its just the wifi being so randomly awful, with no obvious reasoning.

I've spent about 6 hours since yesterday reading lots of posts on the forum and its really hard to find another persons issues to be exactly the same, as we all have our own circumstances and environments, plus a lot of people don't post the solution with the right technical information to aid anyone else.

I'm certainly picking up the following from my research here:

1. Interference from other devices, there is a lot that sits on the 2.4ghz and less on the 5ghz.

2. SH2 IMO seems to be a poorly handling wifi as lots of things are connecting to it instead of the discs and plenty of chat here complaining about the SH2's lack of customisation in the settings.

3. Doing away with the SH2 transmitting wifi and use the discs instead - In lamens terms how is this achieved? Do I have to wire to each disc?

4. Buy a new mesh system wired into the SH2 or a mesh system and do away with the SH2.

5. A lot of people try different channels and different modes but generally that never appears works for their circumstances.

6. I had a look on a wifi analyzer app, trying to get my head around what it suggests.

7. Haven't seen much chat about SH2 Modes 1, 2 or 3.