Network not starting up on boot
Solution 1:
You are likely missing the line for this in the interfaces file. Open /etc/network/interfaces and check if there is a line for eth0 If not add the following:
auto eth0
iface eth0 inet dhcp
This will add the eth0 interface - and use DHCP on boot and wakeup.
If you're still not getting DHCP response you may also need to add dhcp back into defaults:
sudo update-rc.d dhcp3-server defaults
Solution 2:
What does ifconfig -a show when it's not working? Is there an eth0? If it's not, I'd check the modules blacklists /etc/modprobe.d/blacklist*. I would have expected the recovery console to honour these though so moving on...
If you do have an interface, it could be some dodgy config inside network-manager. Recovery mode just uses some defaults IIRC so I'd open up the network settings (right click the applet, click edit connections) and check a few things:
- Connect Automatically is checked
- You have a MAC address
- MTU is automatic
- 802.1x security is disabled
- IPv4 is set to Automatic (DHCP)
- Require IPv4 is checked
- There should be no special routes
- IPv6 is set to ignore
If ifconfig -a isn't showing an eth0 device, it could be something bizarrely hardware specific. What does lspci | grep net show? If nothing, do you know what the network chipset is?