The connection appears to be fine in every other way. All my other machines seem to be OK too. No DNS issues on them. I tried using a fixed IP rather than DHCP, but I get the same issues.

I got the same issue on a different network too There are quite a few other people having this exact same issue. I bet there's something reeeaaaallly simple that will fix it. Just need to know what it is!

At the moment I'm having to use the browser to get to the repositories and download from there.