Setting up a bridged connection

Install bridge-utils package

# apt-get install bridge-utils

If
you have more than one network interface and you want to join a second
interface to the same network (connect another computer through that
interface like a wlan) ang get a connection …
First you have to setup a brx interface on the interfaces file (debian) adding…

$ nano /etc/network/interfaces

auto br0
iface br0 inet static
address 10.10.0.23
netmask 255.255.255.0
gateway 10.10.0.1
bridge_ports eth0 #the interface that have the connection to the gateway
save and close

Restart networking

$ /etc/init.d/networking restart

Now Our active interface is br0

Next, you have to add a second interface to that bridge

$ brctl addif br0 ath0

Confirm the brdige

$ brctl show

Now connect some computer to ath0 interface and it has to be connected with 10.10.0.1 gateway!
To destroy the bridge just type

$ ifconfig br0 down

$ brctl delbr br0

delete the inserted lines on the interfaces file and restart networking

$ /etc/init.d/networking restart