Periodic Partial Connection Losses, DNS Issues?

[david2609]

I'm a new customer who got connected near the beginning of August and have just recently been getting problems with my connection. The last two days I have on occasion lost the ability to connect to specific sites, and for some reason it appears to affect my ethernet connections more than my Wifi (but it does still happen to those eventually too)

When it happens, I'll still be able to connect to things like Google, Amazon, and Youtube, plus a handful of other sites, but am unable to connect to The BBC, this BT site, Reddit, Twitter, The Open University (which is v.important), as well as what seems to be the majority of other websites.

To fix the problem I am having to restart both the broadband box and the router, restarting just one does not fix it. I do not have a separate router to attempt troubleshooting via that.

I am aware that there is work happening in my general area (although these issues seem to crop up at any time, not just during normal work hours) and so I wouldn't be surprised if that were at least part of the cause, but is there a known issue with the DNS servers (or the general infrastructure) at the moment? I have seen past comments mentioning that BT's servers are notoriously bad, but I have no way to know how true this is and I've gone nearly a month without any such issues.

I have not directly gone into fault reporting yet because it appears to be a simple fix even if it is annoying, I'd just like to know if it's just me experiencing this.

[naylor2006]

Next time the fault occurs, manually configure 1.1.1.1 or 8.8.8.8 as the DNS server on a given device and see if it solves it for that device.

You cant wholesale change the DNS servers to avoid using BT's unless you run your own DHCP server or further have your own router, the former can be done with a PiHole utilising its DHCP function, then in there you can set DNS servers, of course you'd need to turn off DHCP on the SH.

[david2609]

The devices in question use google's 8.8.8.8 & 8.8.4.4 as well as cloudflare's 1.1.1.1. I am aware that I cannot stop using BT's DNS. None of them seem to make any difference, the only solution appears to be a total restart.

As for using a PIhole, well my Pi is currently out of order because the USB power supply (genuinely) burned out and I haven't had cause to buy a new one as I was only using it for blocking ads on Duolingo.

It's just something frustrating and annoying while being confusing at the same time.

[naylor2006]

Then it probably isnt DNS related, although I cant say for sure that Cloudflare or Google werent having the same issue at the same time when you are experiencing the issue.

It might be worth trying a VPN app like Nord.....when you switch this on it funnels everything through a given location and a completely different route out to the internet. So long as your internet isnt literally down it will likely still connect during these failures, if you find putting your self in the US, Europe etc....is working then perhaps there is some freaky issue out of your control, otherwise its likely something internal.

You say also that rebooting the router doesnt solve it, rebooting the ONT as well is required, this potentially points to an issue outside your property, quite hard to say.

[david2609]

Unfortunately I think I've narrowed down the problem to an issue with the DHCP server not properly assigning ipv4 addresses.

I suspected it would be something to do with devices connecting since it would always seem to happen in the morning when PCs get booted up for the day. What seems to happen is that it either isn't releasing the ips properly or it is trying to assign them after marking them as unavailable. An ipconfig /all with a none static ip shows it running through ips attempting to assign one with them switching between preferred and duplicate. With a static ip, it simply switches between preferred and duplicate, seemingly forever.

Oddly enough, setting to another unused static IP eventually DOES allow a connection, but I do not get full connectivity back. I regain access to the router software, but sites seem to shift from being accessible and being inaccessible. BBC works, and Reddit doesn't, or vice versa. Sometimes neither will work, sometimes both will. This is without restarting the network equipment after setting my PC to a new static IP (I suspect automatic would keep rotating through addresses permanently)

[naylor2006]

Might be worth trying a different router at this point.