Do you have a 3c905B with Wake-On-LAN connected?

[Donald Becker]

On Fri, 19 Feb 1999, Vaclav Hanzl wrote:

> Subject: Re: Do you have a 3c905B with Wake-On-LAN connected?
> > If you have a 3c905B with the Wake-On-LAN cable connected to the
> > motherboard, please try the following:
> 
> Yes, it works!
> Exactly as you described it.

Excellent!

Thanks for the report -- I worked on this until about 8AM, and could easily
have overlooked something fundamentally broken in the code.

One of my goals is to have large clusters that can incrementally powered up
as required.  But I also want WOL to be easy to use for individual machines.
I'm open to suggestions about the best interface here.

My initial thoughts are that the wake-up program be little more than it is
right now -- a single-function program that takes the Ethernet station
address and transmits a Magic Packet (Note 1).
It must be run as 'root' (Note 2), although it's designed to be safely
installed as set-UID if needed.
A user-friendly script or GUI can look up the Ethernet station address in a
database e.g. /etc/ethers that's generated with 'ping' and 'arp' while the
target machines are running.

The program to put the adapter into Wake-On-LAN mode is very, very chip
specific.  It should probably be merged into the device drivers, although
the interface will be nasty -- there are too many options.


1: Yes, they are really called "Magic Packets", (tm) of AMD.
2: "Magic Packets" must usually be physically broadcast or directed unicast
packets -- packets physically addressed to a host that won't respond to ARP.
This low level of raw packet generation is reserved for 'root'.

Donald Becker					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html