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

[andymoss123]

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.

[Keith_Beddoe · Accepted solution]

@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

[licquorice]

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

[andymoss123]

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.

[Keith_Beddoe]

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

[andymoss123]

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

[licquorice]

Turn off MAC randomisation on your devices.

[andymoss123]

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

[rbz5416]

@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.

[andymoss123]

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....