It looks like you're running: ifconfig ethO up <-- with O, as in the letter.
Please note that AwesomeMachine was saying to use eth0 <-- 0 (zero), as in the number.
You can also try running
While you're hardwired to make sure that the interface is seeing a detection. (See "Link Detected" field):
# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
Advertised auto-negotiation: Yes
Port: Twisted Pair
Supports Wake-on: d
Link detected: yes