I run Ubuntu 12.04 as my main office OS along with a number of other users. We operate on either a wired corporate network or on a wireless connection (those of us with laptops and wireless cards at least). For those of you in the academic world the wireless connection we use is eduroam. Over the summer a number of major changes were made to our (Windows) server due to security flaws and since then all of those users running Ubuntu (12.04) cannot update their systems over the wired connection (although the wireless connection works fine). I realise that this is not a Ubuntu problem per se but our administration run solely on windows and have no experience of running Linux systems so they are struggling. Since a number of us have to use linux systems we have to resolve this.
What we know so far:
Admin have checked and port 80 (which we believe Ubuntu uses to update through http) appears open to windows systems.
Ubuntu 12.04 systems it seems cannot see port 80 and become very slow to resolve the repository mirrors when running apt-get update eventually timing out.
Interestingly our admin checked Ubuntu 13.10 in a virtual box inside windows this morning and it updated fine. Is there some innate difference between Ubuntu 12.04 and 13.10?
Our admin suspect the antivirus inside the firewall which checks all incoming traffic is the problem.
I wonder what checks and advice can you offer so that we along with our network admin can resolve this issue?