[Wylug-help] peer to peer wifi programming

[simon]

On Thu, Jul 20, 2006 at 11:31:26AM +0100, Yiannis Gatsoulis wrote:
> You are right, apologies for not mentioning that. What I ve done (which 
> seems to be working now) is that (using the gnome network settings 
> dialog) I am assigning a static IP leaving blank the ESSID field. 
> Activating the interface and changing the mode to ad-hoc. Both in the 
> client and the server. After a while an iwconfig gives me that ESSID is 
> something like Private Interferometer Network.... A quick google did not 
> yield any results.... so I am guessing that the machines in ad-hoc  mode 
> create a network between them.
> 

Hi (again),
Yes your understanding on ad-hoc networks is correct, they agree that
one will act as a master. When this one moves out of range, the
remaining renegoiate for the role.

One gotcha that you need to look out for is BSSID. When 2 machines
ad-hoc together the agree on a BSSID (in addition to the prescribed
ESSID), normally the MAC address of whichever takes the role of master.

[BSSID shows up a 'Cell' in iwconfig.]

If you have 2 sets of 2 machines they can agree on different BSSID's and
even when they move close enough together they still can't see everyone as
the different BSSID's - which ad-hoc netorking treats as seperate
networks.

The solution seems to be to set a BSSID on all of your machines, this
way they'll all be able to talk.

As noted in my other email, if you're thinking of more that 2 mobile nodes
on the net you might be interested in OLSR (meshing protocol).
Simon.