I found the source of my problem: network-manager had been re-installed on upgrade (I had previously uninstalled it) and it is somehow preventing ifup from working. "apt-get remove network-manager" fixed the issue for me - ifup works.
I found the source of my problem: network-manager had been re-installed on upgrade (I had previously uninstalled it) and it is somehow preventing ifup from working. "apt-get remove network-manager" fixed the issue for me - ifup works.