Vagrant hangs with message “Waiting for domain to get an IP address…”

The problem may be (it was in my case) that there are firewall rules preventing NAT firewall rules for the virbr0 network device created by Vagrant via libvirt, which may look like the following (excerpt of iptables -L -n):

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --       ctstate RELATED,ESTABLISHED
ACCEPT     all  --

A possible fix is to disable those restrictive rules (for example, clear all iptables rules before starting the Vagrant machine).

Wake-on-LAN (WoL) in Linux is disabled by default. How to enable it without ethtool.

Accomplishing the simple often takes a day or two.

According to countless tutorials on the internet, in order for a working WoL, you need to fulfill the following preconditions (where point 4 below is rarely mentioned [that’s why this article exists]):

  1. An ethernet hardware/card supporting WoL
  2. Enabling WoL in the BIOS
  3. Enabling the WoL feature on the ethernet card (usually using the user space tool ethtool)
  4. Enabling the WoL feature in the Linux kernel (and this was the major pitfall for me)

Support of WoL can be checked for a given ethernet card in the following way:

ethtool  | grep Wake-on

According to my own experiments on my local hardware, WoL seems to always be enabled by default:

Supports Wake-on: pumbg
Wake-on: g

Because it already prints Wake-on: g, signalling that WoL is enabled (for Magic Packets), one is tempted to not run ethtool -s <card_label> wol g to achieve the same.

However, this ethtool command does at least one other thing, being equivalent to the following:

echo enabled > /sys/class/net/<card_label>/device/power/wakeup

And the main pitfall is: After a reboot, cat /sys/class/net/<card_label>/device/power/wakeup will return disabled.

That is why attempts to make WoL work without ethtool may fail. The feature will stay disabled in the Linux kernel, which will completely shut off the ethernet card in most powersave and power-off states. (I verified this observing the LEDs of a connected ethernet switch).


On modern Linux systems, given supporting hardware, it seems to be enough to write the string enabled to /sys/class/net/<card_label>/device/power/wakeup to make WoL work. ethtool doesn’t seem to be required any more for that, since Ethernet cards seem to already be configured properly by default. The Ethernet card will stay powered in most power-save and power-off states, so that it can receive Wake-on-LAN packets.


“Green Energy” complication: gdm3 suspends machine after 20 minutes: A solution

I just posted a bug report on

The solution to the problem is further down in the bug report.

Dear Maintainer,

gdm3’s default dconf energy settings suspend the machine after 20 minutes.

This is independent of the power settings made by an unprivileged user within a Gnome login session.

While this could be forgiven on a locally accessible desktop machine, it also suspends remote/headless machines (e.g. in a data center). Activity on a SSH terminal or VNC connection does not prevent this issue. Having no easy way to re-wake remote machines, this may create highly inconvenient situations for administrators. In addition, unexpected suspension may also have disastrous consequences, depending on the use of the machine.

To reproduce, install task-gnome-desktop and wait for 20 minutes on a machine which supports power management.

The offending settings can be printed to the console. As superuser:

su -s /bin/bash Debian-gdm


dbus-launch gsettings get org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type

dbus-launch gsettings get org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout

This prints ‘suspend’ and ‘1200’, respectively.

For quicker reproduction of the problem, reduce the timeout to 2 minutes:

dbus-launch gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 120

Then reboot and wait 2 minutes.

To turn off suspension, set:

dbus-launch gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type nothing

Michael Franzl