I met a strange problem. When I use LiveCD to install ubuntu 12.04 LTS, I was able to connect to Internet through wired connection, choosing "Try Ubuntu".
But when I installed it, it could not connect:
ifconfig -a shows that eth0 does not have inet address
auto eth0 iface eth0 inet dhcp
interfaces, then restart networking, it says:
Reconfiguring network interfaces... Failed to bring up eth0
I tried to set static ip, but still no connection.
I tried to delete 70-persistent, but still no connection.
I tried to reinstall network driver, but still no connection.
What can I do? Thanks.