I have my computer connected to the internet through my college's network. A few days ago, the network connection stopped working in both Windows and Linux. At first, I thought I had inadvertently messed up the settings in Windows, but discovered the problem in Linux. Eventually, out of frustration, I changed my computer's name in Windows, and it worked again in Windows. Linux wouldn't even finish loading, presumably because the network wasn't working right. It correctly configured my ethernet card with all of the right numbers, and then it stopped once the boot process was complete and it wouldn't load any interface except failsafe. Today, I tried it in failsafe, I ran ifdown for my ethernet card, logged out, started KDE, rebooted the system, and everything works. Was this magic? Did I just need to run ifdown and then ifup? I'm happy that everything works again, but I want to prevent this problem or know why my attempts to solve it worked.

Are you sure the computer stopped completely during boot? Did you wait at least five minutes? Sometimes if the machine is having DNS issues (nothing in /etc/resolv.conf, and your own hostname isn't listed in your hosts file), it waits at least two minutes for the DNS request to time out. During this wait, it can appear like your system has completely stalled (especially if you have a fast system... waiting two whole minutes is like eternity ). Since you'd likely be using DHCP for a college connection, something probably went wrong when it came time to update your DNS servers, which is why reconfiguring the network device worked.