ubt0 macaddress cloning

[Maksim Yevmenkin]

Hello,

On Nov 18, 2007 2:04 PM, Marten Vijn <info at martenvijn.nl> wrote:
> On Sat, 2007-11-17 at 18:10 -0800, Maksim Yevmenkin wrote:
> > Marten,
> >
> > > Is there a way to change the macaddress of a ubt (ng_ubt) device?
> >
> > short answer is no. not with the standard hci interface.
> >
>
> aye thanks,
>
> Actually I have more general a question,
>
> If I am rolling out a grid of embedded systems with bluetooth,
>
> Say 5 nodes, I would like to configure my client device (GSM) only once
> to have a pairing with will be valid for all nodes.

it depends. basically the result of pairing is a link key. as long as
the link key is the same on both ends, the connection can be
established.

now, lets say your gsm device has bd_addr_gsm and your embedded
systems have bd_addr_embed1...n.

assuming you have a total control over bluetooth stack on your
embedded nodes, you can assign the same link key for bd_addr_gsm on
each embedded node. assuming you are running freebsd on your embedded
nodes, all you need to do it to make sure all the embedded nodes have
the same /etc/bluetooth/hcsecd.conf file which assigns the same link
key to bd_addr_gsm.

the trick part is the gsm device. the problem here is that you have to
make sure that gsm device is using the same link key when it tries to
talk to your embedded nodes. if your gsm device is a phone, then you
need to somehow program the same link key into the phone's database
for bd_addr_embed1..n.

another alternative is to program link keys into bluetooth device
themselves, however this assumes that you have complete control over
bluetooth devices on both ends and amount of nodes in  your embedded
network is less than amount of keys bluetooth device can store in its
internal memory.

> Would there be a way to share this pairing for al nodes? Assuming there
> way to distribution method between the nodes?

like i said, you can share link keys, but you need to control both
ends of connection to pre-share link keys.

thanks,
max


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> Marten
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