"Create Network..." Ad-Hoc vs. Master

[j bootlab org]

> Mainly because I wasn't sure what other implementations of Ad-Hoc mode
> did for this.  It appears that OS X sets the card to use DHCP when you
> use "Create Network..." option in the AirPort menu, but its unclear to
> me how the thing gets an IP address then.
OS X does not use Ad-Hoc mode for "Create Network...", but Master
mode(computer acts as access point).
This is possible with the hostap driver, i do not know how Master mode
support is for other wireless drivers right now, but since hostap
was selected for the upcoming common wireless driver branch in 2.6,
at some point it might be possible to do so with all wireless cards.

using Master mode on the computer that creates the network.
[also has the advantage that you are not limited to the 2Mbit Ad-Hoc
mode is limited to, or did that change by now?]

After switching into Master mode a dhcp server is started on the
computer that acts as an acess point.
(using a private 10.x.y.0/255.255.255.0 or 192.168.x.0 network not used
by any other interface). 
it also does NAT/provides internet access, if another network connection
exists(Ethernet, Modem, Bluetooth, IrDA...).


j