[SOLVED]WOL simply not working...

Wesman26 · 2015-01-21 04:22:00

And I'm not sure why. For background this is a newish server I'm playing with that I made out of old desktop parts. The Motherboard is an ASUS M5A78L-M LX, which uses a Realtek 8111E (which is not listed as one of the problematic NICs on the WOL wiki entry). I followed all the instructions on the wiki as far as I can tell and wol doesn't seem to do anything while the server is off.

Right out of the the gate this was my ethtool check:

# ethtool enp2s0 | grep Wake-on
        Supports Wake-on: pumbg
	Wake-on: g

So far so good. So I moved along to:

# ethtool -s enp2s0 wol g

and set up port forwarding on my router for port 40000 (the default port for wol). Just for good measure I also appended

ExecUpPost='/usr/bin/ethtool -s enp2s0 wol g'

to my static ip netctl profile, and checked the following:

# cat /sys/class/net/enp2s0/device/power/wakeup
        enabled

Despite all of this, the wol command:

wol -p 40000 -i 192.168.2.37 40:16:7e:a8:8d:78
        Waking up 40:16:7e:a8:8d:78...

appears to do absolutely nothing.

I've looked over the wiki entry and the man page for wol, but I'm not sure what more I can do. Any help is greatly appreciated, and thank you in advance.

--Wes

Update:
Found an old post from 2011 where this was solved with the r8168 driver from the repos and blacklisting r8169. Tried it out, but to no avail.

Update2:
Further research finds that the above "solution" only works with the r8168-lts driver accompanied by the lts kernel. I'd really prefer to avoid going the lts route, so any further information y'all could find would be superb.

Update3:
I decided to check out the Realtek specific solutions listed in Network Configuration, as suggested in the WOL wiki entry. I set enp2s0 up (although it already was) and went into the BIOS to enable the "LAN Boot ROM" option. Still no response.

Update4:
In order to ensure that the problem doesn't stem from my router I tried connecting the server to my machine directly, but wol still won't go through.

Update5:
Tried to wake it from suspend and it worked perfectly fine. Still no solution for booting.

Last edited by Wesman26 (2015-01-23 01:28:21)

pigiron · 2015-01-22 05:54:32

I fired up Wireshark, then started playing around with this and found that the problem may lie with your wol parameters (or not).

wol -p 40000 -i 192.168.2.37 40:16:7e:a8:8d:78

That command appears to be attempting to send a unicast packet (i.e. the "192.168.2.37"), but if the system you're running the wol command on doesn't currently have that entry in it's ARP table, it's going to first send out an ARP request to get the info that it needs to create the packet(s). But the rub is that the only system that can provide the ARP reply is your target system, and it's powered off. Therefore, no reply; therefore no magic packet(s) sent.

With WOL Magic Packets, you want to send to a broadcast address. You'll notice that the man page for wol says it defaults to using 255.255.255.255 as it's broadcast address, but I've had routers that won't pass that packet on the local network. So in my case I use 192.168.1.255 since I run a Class C network (netmask = 255.255.255.0), and that broadcast address does work with my setup.

Lekensteyn · 2015-01-22 15:41:35

Realtek and WOL, hmm. Just "8111e" is not sufficient to describe the NIC, you have to include the PCI revision for the specific model. For example, the Z68X-UD3H-B3 mobo also has a "RTL8168c/8111c" (according to dmesg) card. lspci -nn says:

02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 02)

This mobo had several issues with WOL in combination with some UEFI BIOSes. The current version (U1l) however works fine.

LAN Boot ROM has nothing to do with WOL. You do have to disable "Energy Star" options or something like that. These settings are needed for compliance with some certifications and result in lower standby power usage, but break WOL.

Wesman26 · 2015-01-23 00:33:33

$ lspci -nn | grep Realtek
02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 09)

That doesn't seem good... Do you know of any work arounds?

I also disabled LAN Boot Room, as I realize now what it's for and enabled Power -> APM Configuration -> Boot from S5 on PME# which sounds like it applies here (according to google).

My wol command is now

wol -p 40000 -i 192.168.2.127 40:16:7e:a8:8d:78

as I should have been directing it toward the broadcast ip. I had to set my subnet mask to 255.255.255.128, and modify my static netctl configuration accordingly, because my router won't port forward to the default broadcast ip (192.168.2.255). Despite this I'm still not able to boot using wol.

Thanks for the input, any more suggestions are more than welcome.
--Wes

UPDATE:
After changing my subnet mask I was trying wol with my laptop, which uses wifi. This was obviously a mistake as magic packets can only be sent over wired connections, which I now know. Long story short, with the subnet mask switched my desktop is able to start up the server. Thanks so much!

Last edited by Wesman26 (2015-01-23 01:28:01)

Arch Linux

#1 2015-01-21 04:22:00

[SOLVED]WOL simply not working...

#2 2015-01-22 05:54:32

Re: [SOLVED]WOL simply not working...

#3 2015-01-22 15:41:35

Re: [SOLVED]WOL simply not working...

#4 2015-01-23 00:33:33

Re: [SOLVED]WOL simply not working...

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