Sorry for the vague nature of this report. I'm not sure what the root
cause is, or the critical package, but a recent update to Wheezy/sid
testing has broken networking.
I had been using a static IP address on 2 separate AMD64 systems, with
several NFS mounts. After doing a general update and rebooting the
system, networking did not start on either machine.
Typing "ifconfig" listed the lo device only.
Typing "ip address show" yields:
1: lo: (stuff I did not record)
2: eth0:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether (MAC Address I didn't bother to recorded)
The work-around is to use dhcp to assign the IP. ("dhclient eth0")