This topic

BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 15:07:50 GMT

Hi, I have an interesting issue with Smart Hub 1. Suddenly, the 2.4Ghz channel won't connect to the internet. I can 'connect' with a 'no internet' message, but I can't access the router settings. 5Ghz channel works fine. I have tried restarting everything, turning 2.4 channel off and on, but to no avail. Just wondering if someone can point me in the direction of where to start looking for a solution.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

Keith_Beddoe — Fri, 19 Jan 2024 15:10:29 GMT

@andymoss123

Welcome to this user forum for BT Retail phone and broadband customers.

Try a factory reset of the home hub.

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

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

licquorice — Fri, 19 Jan 2024 15:12:29 GMT

@andymoss123 Is that from multiple devices or just one device that can't connect?

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 15:54:35 GMT

This is from all devices. I've logged into the router via 5 Ghz, and can see 2.4GHZ has 16 devices apparently connected! There's four that I know are genuine, and they have Mac addresses and IP addresses. The other 12 only have MAC addresses, no IP address, which suggests they aren't actually connected??!! Not sure what's going on.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

Keith_Beddoe — Fri, 19 Jan 2024 16:02:58 GMT

Old stale entries preventing new connections. Only a factory reset will remove those.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 16:07:59 GMT

OK, I'll let my boys know that Roblox will have to be curtailed! Cheers.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

licquorice — Fri, 19 Jan 2024 16:19:36 GMT

Turn off MAC randomisation on your devices.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 16:57:33 GMT

I didn't think MAC addresses were random. IP, yes, but I thought the MAC address was the MAC address.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

Anonymous — Fri, 19 Jan 2024 17:05:39 GMT

@andymoss123

Many modern mobile devices default to using a random MAC address for security. That leads to the allocation of multiple IP addresses against "phantom" MAC addresses. The BT Hubs apparently have abug where these are never released from the DHCP serer & so it runs out of addresses.

As there are no security issues with your own network, you can safely disable randomisation on your devices for your own network.

But having said all of that, if you only had a small number of devices allocated anyway, that's not likely to be the issue. Although you didn't say how many 5Gz devices you could see, the DHCP server has some 189 addresses available. But in any case a factory reset clears them.

Maybe look to you local Facebook Marketplace where you can probably pick up a replacement for a tenner or so.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 17:03:08 GMT

As an update...I factory reset and things seemed to work, but I went into the router settings and changed the SSID of the 5GHZ channel. This seemed to screw things again. I did another factory reset, and left as is, and it seems to be working....

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

licquorice — Fri, 19 Jan 2024 17:03:17 GMT

Apple devices and some Android devices now have a cunning wheeze of randomising MAC addresses each time you connect, supposedly a security meaure. All it does is fill the hub with stale entries.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 17:07:58 GMT

Ah, I see. It doesn't look like my tablets have the function, but my iPhones do.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

Keith_Beddoe — Fri, 19 Jan 2024 17:08:36 GMT

Not always so. MAC randomisation, sometimes called private addressing, was introduced by Apple some years ago, and then adopted by Android and Windows.

Its supposed to prevent a device from being tracked from one wireless network to another. It doe that by assigning a random MAC address to the connection, instead of the real device MAC.

This causes all sorts of issues, especially on the home hub, as it creates lots of "unknown device" entries, and eventually uses up all of the internal routes, preventing new connections. It alse upsets any access controls.

With third party routers, these "stale" entries are removed by a soft reset or power reset, but not on the BT Home Hubs, owing to a very old bug in the software.

The only way to remove these entries, is with a factory reset.

Unless yo disable MAC randomisation on any connected devices, the problem will eventually re-occur.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 17:19:10 GMT

So if I was switching, say, my iPhone from the 5Ghz channel to the 2.4Ghz channel, would this create a new MAC address? Assuming they had different SSIDs.

Re: BT Smart Hub 1 - No internet on 2.4Ghz Channel.

andymoss123 — Fri, 19 Jan 2024 17:24:03 GMT

The redundant MAC addresses only seem to be on the 2.4 channel.