Several websites stopped working at around 10:00 AM today through my 5G Home Broadband

[Luigi]

Access to several websites, including dropbox.com, stopped working in the morning today. I've restarted my 5G Home Broadband router but that didn't help. I can access the affected websites over my mobile connection with a different provider.

[Wobbly1]

I'm not being funny to whom mans these forums, but Three tech support are A JOKE! Hours on the phone "we dont have network issues, you shouldnt play competitive games unless using a hardline". They even offered to cancel my contract "as a solution" to a DNS issue. 

"I'm going to adjust your wifi settings"  Why? "Because its wireless and has packet loss". There was NO packet loss on my connection, im lusing a LAN and they was actually talking about changing from IPv6 to v4. tried telling me when I go outside its WIFI. It's 5G over LTE, wifi is local. 

It took too long just to get an IR raised, because they believe there are no issues. Everything is dismissive. I hate Three with a passion. Already lost 3 phones and tablet last year to ID and not looked back! 

They're the worst I've ever had to deal with. If I could get another ISP I'd be gone in an instant. 

[Wobbly1]

Same issues, same time as others. 

I changed the APN from 3Internet to three.co.uk, it fixed some issues but then had its own. 

I was going to add my VPN on to the router as everything works via VPN, but thought i'd try default APN settings in the router page and it fixed it instantly. 

I can access all Alexa services, Nintendo, all my smart home. Web pages that didn't load are loading fine again. 

[23588]

If you disable the APN 3internet which is more suited to residential use and instead use three.co.uk which is more suited to mobile phone use you will end up having no ability to ever port forward and put yourself behind a CGNAT, which is the worst thing.

The best thing would be for Three to fix whatever it is that their service engineers have broken.

[pfalkingham]

Thank you - changing the APN to three.co.uk worked for me.

[pfalkingham]

I did loads of testing yesterday.  Looks like DNS capture from Three is failing to resolve Ipv6 addresses:

persistent DNS resolution failures when using Three’s 5G home broadband service. The issue is reproducible and affects multiple domains (e.g. basicappleguy.com, GitHub Copilot endpoints).

Symptoms:

• Certain domains fail to resolve or time out when using Three’s default DNS servers.
• Example:

nslookup basicappleguy.com

Server: 94.197.33.33

*** Request to UnKnown timed-out

• Forcing resolution against a public resolver (Google 8.8.8.8 or Cloudflare 1.1.1.1) works immediately:

nslookup basicappleguy.com 8.8.8.8

Non-authoritative answer:

Name: basicappleguy.com

Addresses: 198.185.159.144, 198.49.23.144, 198.49.23.145, 198.185.159.145

Environment:

• Three 5G router in IP Passthrough mode → eero mesh router.
• DNS on eero set to 8.8.8.8 / 8.8.4.4.
• Despite this, DNS queries are still being intercepted and answered by Three’s resolver (94.197.33.33).

Impact:

• Some websites and services are completely inaccessible.
• GitHub Copilot in VS Code fails to load conversations.
• Other domains resolve normally.

___

I sent the above to support chat yesterday, but they of course had to work their way through the script "have you turned the router on/off again? have you reset the Router? have you reset the eero" but I didn't have time to work through all that so i pasted the above and asked them to escalate it.

Unfortunately, from about 10am today the Router won't even connect to Three at all.


It's mildly inconveinient in that when it was connecting I have to use a VPN to use e.g. copilot for coding. But what's worse is that the eero servers aren't reachable. So that means I can't add the second mesh node to my network, even though I can connect to the internet, because eero says the network's offline (it isn't, and I'm using it).  So now my mesh network (that I hard reset during trouble shooting) is broken and missing nodes.  

[edit] - checked Threes network service checker and the network's down in my area at the moment, so that explains the lack of connection from the Router.

[23588]

I've never used threes default DNS so that rules that out.  Problem remains on all of the other popular DNS service providers out there (including three's own).

[pfalkingham]

Even if you’ve set custom DNS, it looks like Three intercepts all DNS traffic on port 53 and redirects it to their own resolvers. Unless you’re using DNS-over-HTTPS (DoH) or a VPN, your queries still go through Three’s DNS.

You can test it like this:

nslookup github.com

→ If the “Server” line shows something like `94.197.33.33` or `2a04:…`, that’s Three’s DNS.

Then run:

nslookup github.com 8.8.8.8

which forces googles DNS, and it should return full details.

___

Following @Wobbly1 I changed APN to three.co.uk and now the broken sites work, but I still get the same output as above from nslookup, which I think means it's still using three's DNS servers, but now has a better fallback for IPv4?

[pfalkingham]

Even if you’ve set custom DNS, it looks like Three intercepts all DNS traffic on port 53 and redirects it to their own resolvers. Unless you’re using DNS-over-HTTPS (DoH) or a VPN, your queries still go through Three’s DNS.

You can test it like this:

nslookup github.com

→ If the “Server” line shows something like 94.197.33.33 or 2a04:…, that’s Three’s DNS.

Then run:

nslookup github.com 8.8.8.8

→ If that works instantly, it confirms the interception.

here's my input and output for the above:

PowerShell 7.5.3
PS C:\Users\pfalk> nslookup github.com
Server: UnKnown
Address: 2a04:4a45:9:b:188:31:250:128

*** UnKnown can't find github.com: No response from server
PS C:\Users\pfalk> nslookup github.com 8.8.8.8
Server: dns.google
Address: 8.8.8.8

Non-authoritative answer:
Name: github.com
Address: 20.26.156.215

The only way to truly bypass it is to use DoH or a VPN.

[pfalkingham]

Even if you’ve set custom DNS, it looks like Three intercepts all DNS traffic on port 53 and redirects it to their own resolvers. Unless you’re using DNS-over-HTTPS (DoH) or a VPN, your queries still go through Three’s DNS.

You can test it like this:

nslookup github.com

→ If the “Server” line shows something like 94.197.33.33 or 2a04:…, that’s Three’s DNS.

Then run:

nslookup github.com 8.8.8.8

→ If that works instantly, it confirms the interception.

here's my input and output for the above:

PowerShell 7.5.3
PS C:\Users\pfalk> nslookup github.com
Server: UnKnown
Address: 2a04:4a45:9:b:188:31:250:128

*** UnKnown can't find github.com: No response from server
PS C:\Users\pfalk> nslookup github.com 8.8.8.8
Server: dns.google
Address: 8.8.8.8

Non-authoritative answer:
Name: github.com
Address: 20.26.156.215

The only way to truly bypass it is to use DoH or a VPN.

[pfalkingham]

Even if you’ve set custom DNS, it looks like Three intercepts all DNS traffic on port 53 and redirects it to their own resolvers. Unless you’re using DNS-over-HTTPS (DoH) or a VPN, your queries still go through Three’s DNS.

You can test it like this:

nslookup github.com

→ If the “Server” line shows something like 94.197.33.33 or 2a04:…, that’s Three’s DNS.

Then run:

nslookup github.com 8.8.8.8

→ If that works instantly, it confirms the interception.

here's my input and output for the above:

PowerShell 7.5.3
PS C:\Users\pfalk> nslookup github.com
Server: UnKnown
Address: 2a04:4a45:9:b:188:31:250:128

*** UnKnown can't find github.com: No response from server
PS C:\Users\pfalk> nslookup github.com 8.8.8.8
Server: dns.google
Address: 8.8.8.8

Non-authoritative answer:
Name: github.com
Address: 20.26.156.215

The only way to truly bypass it is to use DoH or a VPN.