Re: Waking up remotely a Linux box

From: Juha Laiho (Juha.Laiho_at_iki.fi)
Date: 10/11/05 

Date: Tue, 11 Oct 2005 14:54:38 +0000 (UTC)

Augustus SFX van Dusen <ASFXvD@story.net> said:
>I have a Linux box in a remote location that I would like to access every
>so often.
...
>I understand that some NICs have the capability to turn the power on in
>their host computer whenever they receive a particular Ethernet packet. I
>therefore have two questions:
>
> 1) What such NICs are supported under Linux?

I think no special support for WOL (wake-on-lan) is needed from the OS;
the wakeup happens way before the OS is loaded. So, any Linux-supported
NIC with support for WOL should be enough (provided that the motherboard
also has a WOL connector). Intel EtherExpress Pro100 line of cards is
one example of suitable cards.

> 2) Is the scenario I describe a feasible one? Thatis, given the
>appropriate NIC, could I manage to turn on the power of the Linux box from
>a remote location? I can configure the ADSL router at will.

Here I think you have the biggest problem: the router should be able to
send the WOL packet, based on some external trigger. So, quite a lot of
intelligence is needed from the router. WOL packets are structured so
that you only can transfer them within a LAN, so the packet should
originate on the router. Then, you should be able to set up some way
to tell the router to send the WOL packet -- and given the amount of
automated scans over address ranges, the way to send the WOL packet
should be somehow protected so that a random scan won't turn on the
remote machine. 

-- 
Wolf  a.k.a.  Juha Laiho     Espoo, Finland
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