[EdLUG] Network problem

[Dick Middleton]

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