Intermittent web access issues

[tsr2]

My first post on this top seems to have been marked as spam, so I'll try again.
Recently I started having issues accessing certain websites, but others were just fine. I eventually narrowed it down, with some help to whether I was accessing them over HTTP or HTTPS. I access the majority of websites using HTTPS and that works fine, but if I have an old bookmark that uses HTTP it fails, e.g. trying to load google.com via HTTP fails but over https it works just fine. when it fails it waits for a while then I get the error message "The connection to the server was reset while the page was loading."
If I use a mobile hotspot instead of my home broadband the issue goes away.

Similarly a manual check for updates in Windows Update says "We couldn't connect to the update service. ", but it works fine if I use a mobile hotspot.

If I use a Linux box and "wget -d" I can see an HTTP get request, but it doesn't see a response.

My best guess is that something in the Vodafone network is blocking the response. It seems unlikely that Vodafone would block port 80, but I can't see what else it could be.

Has anyone else seen similar issues?

[Cynric]

.@tsr2 Hopefully my suggestions are more successful than a certain aeroplane 🙂

Try alternative DNS settings other than the Vodafone ones, e.g. 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).

Secondly it could just be your browser getting strict about HTTP. Nearly all of them default to blocking HTTP and that includes portions of a page that is initially reached by HTTPS. There is likely a setting to be more relaxed about HTTP but it comes with a lot of warnings.

[tsr2]

If can't see how a DNS issue would cause an HTTP failure, but not HTTPS to the exact same address? I might give it a prod when it won't disrupt the whole household, but I don't see it as a serious line of enquiry.

Similarly, if it was a browser issue, swapping to a mobile hotspot would not resolve the problem, so that looks unlikely. I have tried 3 different browsers on 2 different operating systems and disabling all addons.

[Jayach]

Your thoughts are following mine, if it were a browser issue, why would connecting through a mobile hotspot make a difference?

The only thing is, I am not experiencing the same problem, and I am going through Vodafone broadband also.

But if I enter http://www.google.com into Edge, Firefox or Opera it is converted to https://www.google.com whcih I believe is the modus operandi in modern browsers.

No help in solving it, but I think it eliminates DNS as the problem,

[Cynric]

Thinking about DNS I was wondering if the ISP was trying to be "clever" and blocking http and permitting https. It is certainly doable as part of the associated firewall rules (it'd be a daft ISP not to firewall the DNS service). Where I work you cannot pass http around, so some pages with mixed content look quite odd.

I though about browsers because of the difference experienced between mobile and wired devices. There are a number of browsers which have not all got to the same level of rejecting http, and this is not a question of plug-ins - which I had not considered - but just a question of different browser behaviour and what version of a particular browser is installed. Previously I could not remember the following URL at the time of writing, but here is what I was thinking of, https://caniuse.com/?search=http

Annoyingly this site doesn't show whether http is treated as a caution requiring the user to take an action to use it.

[tsr2]

DNS, as such, won't know whether you are using HTTP or HTTPS. It just translates www.google.com to the associated IP addresses.

What should happen is that an HTTP request should be sent to the IP address and the response may redirect the browser to the https link instead. For google.com the HTTP just works on the hotspot, it doesn't require a redirect.

On other sites there is a "301 Moved permanently" response which includes the new URL, resulting in a redirect.

On Vodafone I just don't get any response at all on HTTP, which is suggestive of a firewall, but if Voidafone were really firewalling all HTTP there would be a lot of complaints.

[Cynric]

Can you give an example URL that is demonstrating these issues please?

[tsr2]

For me http://google.com doesn't return any response, eventually resulting in a connection reset while loading error", unless I'm on the hotspot. https://google.com just works.

Similarly http://www.bekospares.co.uk doesn't return any response, eventually resulting in a connection reset while loading error", unless I'm on the hotspot. When I'm on the hotspot it returns a "301 Permanently moved" response and redirects to https://www.bekospares.co.uk.

[Cynric]

Using Brave browser, v1.34.80.
http://www.bekospares.co.uk/ returns "200 Temporary Redirect". Brave automatically tries https, so it went on to load under https. I turned-off the automatic behaviour and it honoured the redirect.

Using Firefox browser, v96.0.1
http://www.bekospares.co.uk/ redirect automatically (can't say if it was a response to the 200 or not as F12 didn't preserve the trace).

Using Edge browser, v97.0.1072.62
http://www.bekospares.co.uk/ returns "301 Moved Permanently" and follows the redirection.

General notes:
* Some parts of the page are HTTP/3 which is not universally supported, e.g. calls to fonts.gstatic.com.
* The server appears to respond differently depending on the browser
* Some elements of the page (e.g. certain javascript files) are blocked by my firewall.
* The homepage source is coded as https everywhere, can't vouch for the javascript and unbagging min.js is a pain.

[tsr2]

The one bit of kit I hadn't restarted was the Vodafone router. Restarting that seems to have resolved the issue.