[SOLVED] BRIDGE and ROUTER - Bridge 3 interfaces and route 1

[Vieri]

I'm new to bridging and would like to know how I can bridge more than two interfaces.

The network layout is as follows:

LAN 1 ----------------------------------|
Internet---ADSL modem/router---SWITCH---Gentoo Shorewall---ATM line---LAN 2
LAN 3 --------------------------------------------------| |
DMZ -------------------------------------------------------

I need LAN 1, LAN 3 and DMZ to be on the same subnet 10.215.144.0/255.255.255.252
The ADSL modem/router's local IP would be 10.215.144.92.
The Gentoo Shorewall gateway would have a bridged interface virtual IP= 10.215.144.91 and the fourth interface would have IP= 172.20.3.4 and would be in charge of ROUTING traffic to LAN 2 (several subnets of type 10.215.0.0) from the remote ATM line endpoint (172.20.3.2).

What would be a SAMPLE NETWORK CONFIGURATION for Gentoo (supposing eth0 connected to ADSL, eth1 connected to LAN 3, eth2 connected to ATM/LAN 2 and eth3 connected to DMZ)?
e.g.:
Compile KERNEL with BRIDGE support
# emerge net-misc/bridge-utils

EDIT /etc/conf.d/net:
bridge_br0="eth0 eth1 eth3"
config_br0=( "10.215.144.91 netmask 255.255.252.0" )
config_eth0=( "null" )
config_eth1=( "null" )
config_eth3=( "null" )
brctl_br0=( "stp on" )
config_eth2=( "172.20.3.4 netmask 255.255.255.0" )
routes_eth2=( "default via 172.20.3.2" )

# ln -sf /etc/init.d/net.lo /etc/init.d/net.eth1
# ln -sf /etc/init.d/net.lo /etc/init.d/net.eth2
# ln -sf /etc/init.d/net.lo /etc/init.d/net.eth3
# rc-update add net.eth0 default
# rc-update add net.eth1 default
# rc-update add net.eth2 default
# rc-update add net.eth3 default

# ln -sf /etc/init.d/net.lo /etc/init.d/net.br0
# rc-update add net.br0 default
# /etc/init.d/net.br0 start

What I'm not sure about is whether I can bridge_br0="eth0 eth1 eth3" or if I have to do that two by two.

I would appreciate any tips/suggestions.

Thanks in advance

[nielchiano]

[Vieri]

Thanks nielchiano.
Bridging several interfaces was quite simple in Gentoo.