http://askubuntu.com/questions/156957/upgrading-11-10-to-12-04-killed-my-network-connectivity ubuntuforums.org/showthread.php?t=2042734
Check above links for more info
http:// askubuntu. com/questions/ 156957/ upgrading- 11-10-to- 12-04-killed- my-network- connectivity org/showthread. php?t=2042734
ubuntuforums.
Check above links for more info