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 its 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?

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

To have your network interface automatically configured via DHCP on boot, add the following lines to /etc/network/interfaces:

auto eth0
iface eth0 inet dhcp

This should bring your interface up even without NetworkManager running. You can even remove the package network-manager, if you will.

Debian/Ubuntu has it's own program to manage servers at boot-time.

Try update-rc.d STARTUP-SCRIPT defaults

Search for the specific script for eth0, and enable it with this.

You could always make you're own script, place it in init.d and running the previous command will make it load at boot time.

or just put those commands(ifconfig up, dhcpcd) in /etc/rc.local (this file get's read everytime at boot-time)