ra0 = wlan interface
br0 = bridge
_____                            _______________
|    |                           |Server        |
|PC_3|-----eth connection--------|br0(eth0,eth1)|----eth connection-------ADSL modem-----> Internet:O
|____|                           |ra0           |
                                 |______________|
                                        |
                                    wireless 
                                    connection
                                        |
                                        |
                               ======================
                               |       Laptop       |
                               |  with wireless card|
                               |____________________|