symbol cell address inquiry

[David Gibson]

On Wed, Jun 26, 2002 at 10:34:52PM -0700, Vic Berdin wrote:
> Hello everyone,
> 
> I noticed that when I'm using a symbol spectrum24 in
> ad-hoc mode, the initial "iwconfig" cell address 
> is set to 00:00:00:00:00:00. This address will only be
> toggled to 02:A0:F8:2F:FA:B7 when I activate another
> machine set in ad-hoc (ofcourse, essids on both
> machines are the same).

That sounds reasonable.  The IBSS doesn't really exist in any
interesting sense until there are at least two nodes in it.  So it
makes sense not to set the BSSID until there is another node around.

> But using an orinoco silver, even without an ad-hoc/
> P2P companion, the iwconfig cell address is always set
> to 00:02:2D:1C:FF:F3 (the correct mac addy).

But setting the BSSID (to something arbitrary) is also reasonable.
But of course if both machines are already set up in ad-hoc mode at
least one of the will have to change BSSID when they come into range
of each other (assuming they have the same ESSID, of course).

> Also, my symbol card's mac address printed at its back
> is actually: 00:A0:F8:2F:FA:B7. This is the same
> address displayed when I issue an "ifconfig" command
> (differs a bit to the "iwconfig" result).

The one displayed by iwconfig as the BSSID is the MAC address with the
"locally administered" bit toggled on.  This seems to be how most
firmwares seem to generate the BSSID.  How it's generated doesn't
really matter as long as it has a good chance of being unique.

The 802.11 standard (at least the edition I have) suggests generating
the BSSID as 22 random bits plus the special "group address" and
"locallly administered" bits set to 0 and 1 respectively.  I've never
seen anything that actually does that though, they just seem to set
the local bit on their own MAC address.  Possibly the recommendation
has changed in more recent updates to the standard - I'm just using
the freely downloadable version from
http://standards.ieee.org/getieee802, which doesn't include the latest
revisions.

> Is this how symbol spectrum24 cards really behave when set to
> function in ad-hoc mode? I mean, the "iwconfig" cell addy without a
> P2P companion is really set to 00:00:00:00:00:00?

I'd say so.

-- 
David Gibson			| For every complex problem there is a
david at gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.  -- H.L. Mencken
http://www.ozlabs.org/people/dgibson