Description:
When waking a host by sending a magic packet over lan, a subsequent shutdown will imply some kind of reboot instead of power off the host. If the host was powered on by pressing the power button, a subsequent shutdown works as expected.

The NIC is a RTL8111/8168B. Whenever power off is initiated by typing: "$ sudo shutdown -h now", the system powers off but restarts after about 5 seconds of being powered off. This only happens if the system was previously started via WOL. After this strange kind of reboot as well as after power up the machine using the power button, shutdown works as expected until the next boot via WOL. The Wake-on mode can be either set to u, m, or g, it does not seem to matter.

This is a newly built rig and thus I don't know which version of linux introduced this bug. Archlinux was installed without any further packages: no acpid, no X, just a pure fresh installation. The GPU was removed after installing, thus the host is accessible over ssh only. Since I don't know if the issue is present in other distributions (I don't even know which distribution actually uses such a recent kernel version), I post it here and not upstream. Feel free to close this report if I was wrong.

Two workarounds are known to me:
i) install r8168-all from AUR and blacklist r8169. This is not an option to me, since a forgotten rebuild of the module after a kernel update will leave the machine in a unaccessible state (accessible over ssh only).

ii) install and use linux-lts. This is the option I actually use.

Additional info:
$ lspci|grep 81
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)

Steps to reproduce:
* Install Archlinux
* Enable Wake on LAN
* Boot by sending a magic packet over LAN
* type: "$ shutdown -h now" as root