[EdLUG] Network problem

[Roy]

Maybe a DNS issue?

Some systems have valid DNS cache entries, so they don't need to do the 
lookup.

IPv4 vs IPv6 one works but not the other?

mirror.bytemark.co.uk is at 2001:41c8:20:5fc::1 or 80.68.83.150

Does using the IP rather than the name in the URL work?

Regards,

Roy Bamford.


On 13/02/2021 10:19, Dick Middleton wrote:
> I've got a really weird problem with my network and I'm at a loss as 
> to what to do.
>
> Just after midnight on Thurs problems were noticed.  Things stopped 
> downloading from the network.  But not everything.
>
> No problems are being seen with Chromebooks and Android phones (wifi) 
> but iPod, TV, network streamer etc have stopped working.
>
> My main linux desktop computer has no problems but a couple of arch 
> linux computers do.
>
> I've narrowed it down using curl; on working systems curling a webpage
>    curl -v http://mirror.bytemark.co.uk I get the index page
> on a non working system it returns nothing - it just hangs waiting.
>
> If I provoke a 404
> curl -v http://mirror.bytemark.co.uk/x then all systems return an 
> error web page.
>
> Similar effect with nc
>
> printf "GET / HTTP/1.1\r\nUser-Agent: nc/0.0.1\r\nHost: 
> 127.0.0.1\r\nAccept: */*\r\n\r\n" | nc mirror.bytemark.co.uk 80
>
> It looks like a routing error but if that was the case all systems 
> would fail and the error page would also not be returned.
>
> My brother has simple home page which is returned normally from all 
> systems; again suggesting it's not a routing problem.
>
> I'm totally perplexed and would really appreciate some ideas
>
> Dick
>