Turn on computer through internet.

brumwald

Gawd
Joined
Aug 1, 2006
Messages
598
Hi

I would like to have the ability to turn on my "server" (isn't really a server since it isn't on 24/7) while I'm away but has access to internet.

I don't have any other server in the same LAN and since WOL deals with MAC adresses that won't work. What I'm thinking is perhaps a PIC or something to do the work.

Would that be possible?
I don't expect the PIC to be able to decode everything but perhaps just set it on listening to a certain sequence. Perhaps the speed of the bandwidth would be an issue. Guess the slowest speed that a router supports is 10 MBit/s? Of course it would be open to anyone that knows that sequence (since the sequence would be transmitted in 'clear-text' it would of course be simple to pick it up with a sniffer) to boot the machine but I don't think that will be a problem.

Another way could be to use a linksy router (don't have one) that runs on linux and where there are hacks that lets you do whatever you want with it basically. I guess that it would be possible for such a router to boot the machine using WOL.
But I have gotten the impression that the models that you can hack are fairly old and I suppose that they don't have great internet throughput and that would be a waste. Of course you could buy one just for this purpose (I also have 3 spare IPs if that would help, but probably not in this case) but that seems like a waste so unless theres a better way...

I think I've seen a solution using a cell-phone but I would rather not rely and maintain that (pay for and 'regulary' renew the subscription).

Or is there another solution?

Keeping the costs down is a priority. The costs of a PIC might be excused (always wanted to learn to do and program them).
 
Yeah that does seem to be overkill.

Although after reading some more I get the impression that WOL doesn't rely on MAC adresses but to IP adresses containing an MAC adress?
Problem with that is that the computer won't have an IP if it's shut down. Will the router still redirect the packet to the right ethernet-port?

A bit OT though, didn't think it was possible without any extra hardware. I'll check it out.

Some links:
http://www.hackernotcracker.com/2006-04/wol-wake-on-lan-tutorial-with-bonus-php-script.html
http://support.intel.com/support/network/sb/cs-008459.htm#1
http://en.wikipedia.org/wiki/Magic_Packet
 
http://en.wikipedia.org/wiki/Wake-on-LAN

How it works
The general process of waking a computer up remotely in a LAN can be explained as such:

The target computer is shut down, with power reserved for the network card. The network card listens for a specific packet, called the Magic Packet. The Magic Packet is broadcasted on the broadcast address for that particular subnet or the entire LAN. The listening computer receives this packet, checks it for the correct information, and then boots if the Magic Packet is valid.


Magic Packet
The Magic Packet is a broadcast frame, transmitted over port 7 or 9. It can be sent over a variety of connectionless protocols (UDP, IPX) but UDP is most commonly used. The data that is contained in a Magic Packet is the defined constant as represented in hexadecimal: FF FF FF FF FF FF followed by sixteen repetitions of the target computer's MAC address, possibly followed by a four or six byte password.
 
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