I've been having an annoying problem for the last 10 days or so. I have a BT HomeHub 5, with both wired and wireless connections. The wired goes, via a BT Powerline adapter, to a BT WiFi Homespot 500 kit (which has a separate 2.4GHz network with a different SSID).
The wireless is split into a 2.4GHz network and 5GHz network with separate SSIDs.
My problem in the last few days has been that when 'one more' device tries to connect (wirelessly or wired) it will fail to get an IP address - on Windows devices this means it'll get a useless 169.* address, on Android and iOS it just fails to connect and reverts to using 4G. Similarly my XBox One, Chromecast and Xbox 360 just don't even try and connect when they don't get an IP address. The XBox One is particualrly explicit in its error message - "Cannot connect to your DHCP server". DHCP makes sense, as once this one extra device fails to connect, any further devices I try to connect will also fail. Even restarting the router seems to make no difference. Any device that was already connected will still work and have full access to the internet and the rest of the home network. After about 30mins (although this is a real guess) everything will just suddenly start working again (I may have to push some wireless devices back onto the network by manually reconnecting them)
When I say 'one more' device above, what I mean is when I add an extra device to the network - e.g. come home and thus my phone tries to switch from 4G to my home WiFi, or I turn my laptop on. It's not one specific device, it's just an extra device and it seems to be the one that breaks the camel's back. I haven't worked out how many devices it is that means that when I add the next one things all go to pot.
I've called up about this and I've had the standard things requested of me - hard reset HomeHub 5 (done so), split out the WiFI networks to be on different SSIDs for 2.4GHz and 5GHz (did so, but this was the case anyway before HomeHub was hard reset) and change wireless channels (done this too, but was already on channels that seemed to be clearest in my local area - now ironically been moved onto a more congested 2.4GHz channel, but this problem also happens for me on 5GHz, so don't think channel selection is the problem.
So, in short, it seems like a DHCP problem where the router fails, after some trigger that I don't quite understand, to offer any new IPs. I've checked and the maximum IP address already assigned is never anywhere near the limit of 192.168.1.253 - instead we're normally up to around 192.168.1.110 or so. I don't know whether this is a hardware fault in the router, an inherent limitation of the router that I've only just come up against (maybe as I have more devices now), or a firmware issue that can be fixed. If it's either of the last two presumably other people have the same problem.
Any thoughts or troubleshooting tips very much appreciated!
Have just started using the new BT smart hub and on previous hubs have been able to assign the IP address to each network device via the hub set-up page.
Have tried this on the smart hub and whilst the facility exists it will not save the IP address. Having looked on the Internet this appears to be a common problem.
I wondered whether anyone had found an easy workaround for this issue?
I have 10 zones, a multitude of iPods, iPads, iPhones, kindles and heaven-only-knows what else sitting on my network and I found that by assigning the IP's I was less subject to duplications and storms. Since swapping to the smart hub I have again been plagued with drop-outs to the extent that BT are now sending me a replacement as it appears to have an issue - that however won't resolve the IP address thing.
Any help greatly appreciated as always