I just lost networking and internet on 2 boxes after updates!
It's a known bug caused by libnl3 and networkmanager packages and here's how I fixed it:

From a working box or boot with live DVD

Save these files to your effected computer.

Download these for 64 bit install:
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-3-200_3.2.21-1_amd64.deb
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-genl-3-200_3.2.21-1_amd64.deb
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-route-3-200_3.2.21-1_amd64.deb

Download these for 32 bit install:
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-3-200_3.2.21-1_i386.deb
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-genl-3-200_3.2.21-1_i386.deb
http://archive.ubuntu.com/ubuntu/pool/main/libn/libnl3/libnl-route-3-200_3.2.21-1_i386.deb

Then goto where you saved them on the system in the terminal and run dpkg 1 at a time till the files are rolled back to these ones.

ie:
sudo dpkg -i libnl-3-200_3.2.21-1_amd64.deb

and so on till all 3 are rolled back.

Then restart NetworkManager:

sudo service network-manager restart


Put a hold on the updates that broke it till they have a newer fixed version:

sudo apt-mark hold libnl-3-200 libnl-genl-3-200 libnl-route-3-200

Once they fix it you can take off the hold.
sudo apt-mark auto libnl-3-200 libnl-genl-3-200 libnl-route-3-200

You'll be back in business!
Cya!