Problem

Ubuntu 9.10 Desktop Edition (and possibly previous versions as well, I haven't tested them) has no network connections after boot until at least 1 user logs in. This means any services that require networking (e.g. openssh-server) are not available until someone logs in locally either via gdm, kdm, or a TTY.

Background

Ubuntu 9.10 Desktop Edition uses the NetworkManager service to take commands from the nm-applet in Gnome (or it's equivalent in KDE). As I understand it, while NetworkManager is running at boot, it is not issued any commands to connect until you login for the first time because nm-applet isn't running until you login and your Gnome session starts (or similar for KDE). I'm not sure what prompts NetworkManager to connect to the network when you login via a TTY.

There are several relevant variables involved in starting up the network connections including:

• Wired vs Wireless (and the resulting drivers, SSID, passwords, and priorities)
• Static vs DHCP
• Multiple interfaces

Constraints

• Support Ubuntu 9.10 Karmic Koala (bonus points for additional supported versions)
• Support wired eth0 interface
• Receive an IP address via DHCP
• Receive DNS information via DHCP (obviously the DHCP server must provide this information)
• Enable networking at the proper time (e.g. some time after file systems are loaded but before network services like ssh start)
• Switching distros or versions (e.g. to Server Edition) is not an acceptable solution
• Switching to a Static IP configuration is not an acceptable solution

Question

• How to start networking on a wired interface before logon in Ubuntu Desktop Edition?

What I have tried

• Per this guide, adding the following entry into /etc/network/interfaces so that NetworkManager won't manage the eth0 interface:

auth eth0
iface inet dhcp

• After reboot eth0 is down.

  • Issuing ifconfig eth0 up brings the interface up but it receives no IP address.
  • Issuing dhclient eth0 instead Does bring up the interface and it Does receive an IP address.

• Completely removing the NetworkManager package in addition to the settings above.

I'm a bit confused with the whole UpStart/SysVinit mangling that's going in Ubuntu currently (I'm more familiar with the CentOS world). However, directly issuing

sudo /etc/init.d/networking start

Or

sudo start networking

does not bring up the eth0 interface at all, much less get an IP address.

See-Also

• How to force NetworkManager to make a connection before login?

References

• Ubuntu Desktop Edition
• Ubuntu Networking Configuration Using Command Line
• Automatic Network Configuration Via Command-Line
• Start network connection before login