I upgraded from Ubuntu 11.10 to 12.04 yesterday. I am running a BSNL Broadband DSL conenction. The wired network suddenly dissapears and the computer stops detecting the ethernet card after sometime. However, after rebooting, it again becomes alright. Specs : Lenovo Ideapad Z570 Intel i5 2nd Gen. processor 3 GB RAM $ lspci | grep Ethernet 03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 05)