Requesting a isakpmd.conf for a wireless setup

[David Rio <drio_(_at_)_perpels_(_dot_)_com>]

Hi all:

I am trying to setup a VPN between a wireless client and a gateway.
I must encrypt all the traffic from the wireless client to the gateway.
There is a problem with this scenario that I don't know how to solve:
Both, wireless client and the gateway are in the same network, wireless
client can reach the gateway directly using its wireless interface.
I can't find the correct isakpmd.conf values that would work with this
scenario.  
Can anyone with this scenario already working explain me how he did it?
 
Have a nice day.