Re: [Hampshire] Very off wifi issue

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Author: James Dutton via Hampshire
Date:  
To: Hampshire LUG Discussion List
CC: James Dutton
Subject: Re: [Hampshire] Very off wifi issue
On Sat, 22 Nov 2025 at 14:44, rmluglist2--- via Hampshire
<hampshire@???> wrote:
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> Hi all
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> This is such a weird problem, it’s going to take me a while to explain it but if anyone is willing to offer a solution, I’d love to hear. The problem: All of a sudden, our wifi has become really bad – disconnecting 2-3 times every 10 seconds. As it came on so quickly (about 6 weeks ago), I put it down to bad weather (however sketchy that myth may be). But now, as a result of a lot of testing yesterday, I’ve determined that it’s to do with the cabled side of the LAN. Please read on…
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> On my home LAN, I have 2 routers – on both of which I have the WiFi disabled. This is deliberate because I don’t want the WiFi “fighting” with each other over channels etc. I realise I could manually set to different channels but bear with me. I repeat – there is no WiFi enabled on either router. The WiFi we have comes from 3 access points scattered around the house. Each device (all TP-Link) is in Access Point mode and setup with its own static IP on the LAN. There are no IP conflicts between the APs and the routers – I have checked.
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> One of the 2 routers I have is a BT Home Hub 5. It’s required to have a DHCP server enabled as, without it, our BT Vision box won’t work. Mindful of this, I’ve disabled DHCP on my other router.
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> Now, with thanks for reading this far, if I allow the BT router to be on at the same time as the other router, our WiFi is awful. Switch off the BT router and all works well. Conclusion: the BT router is not happy playing with the APs. But here’s the real issue. I have configured the APs to use the non-BT router as their gateway and DNS. Therefore, while they are on the same physical network – they should never need to “touch” the BT router. I have also, obviously, disabled DHCP server on all APs so it can’t be some sort of DHCP conflict.
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> Why would the existence of a wired router (remember its wifi is disabled) cause such disconnects to devices connecting to _all_ of my WiFi access points when it’s switched on? It has to be the BT router at the (pardon the pun) root of this doesn’t it?
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> I’ve read about “Double NAT translation” so I’ve moved the BT router to another network i.e. 192.168.1.x instead of what it used to be: 192.168.0.x and that’s made no difference either. FWIW the non-BT router is on the 192.168.0.x network.
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> I have to have both routers switched on and the BT router has to have DHCP enabled for the BT vision box but, as I say, the BT router is the only DHCP server on the LAN. I’ve proved this by trying to connect a device via DHCP with the BT router off and it fails so it’s definitely not a DHCP issue.
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> Anything I could usefully try would be very welcome. It’s driving my kids mad!
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Hi,

I don't suppose you could draw a little text diagram.
The diagram needs to have:
1) Where the internet connection is. (Which router it is connected to)
2) Where each router and AP is. (Which have Wifi enabled, which do not)
3) Physical cables between the routers.
4) The IP address, netmask, and any next hop gateway configured of each device.

But just looking at the symptom you mention:
1) Interference from an electronic device, washing machine, microwave
etc. Have you added any new things recently? Some cheap usb-c power
bricks can cause problems. That sort of thing.
2) Intermittently faulty network cable. Try changing cables, or get a
cable tester.

Note, (2) is the most likely cause.

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