First of all I hope this topic was not covered already elsewhere, but I couldn't find a solution with searching Google and Linuxquestions.org. I also want the debian way via /etc/network/interfaces for my new setup.
The following setup is working without any problems and is faily easy to setup. My Laptop is connected to the university network via wired ethernet eth0 and gets an public IP address from the university DHCP server:
iface eth0 inet dhcp
name Ethernet LAN card
The wireless network eth1 is setup as an ad-hoc network with an private IP address and another DHCP server running on my linux box assigns a private IP address to any computer which connects to my ad-hoc network (primarily for surfing the internet from the kitchen, which has no network socket). The package ipmasq does network address translation (NAT) for the wireless host connected to the ad-hoc network.
iface eth1 inet static
name Wireless LAN card
wireless-key open  s:*************
So far so good. But under WinXP is fairly easy to setup a network bridge between the wired and wireless network interfaces. The huge advantage of that setup is that both my Laptop and any other computer connected to the ad-hoc wireless network get a public IP address from the university DHCP server and all computers are on the same subnet (good for LAN gaming!!!). No extra DHCP server and no NAT are necessary.
How can I adopt my file /etc/network/interfaces to create a network bridge between eth0 and eth1?
I found something which is nearly what I want, but uses static IP addresses:
iface br0 inet static
bridge_ports wlan0 eth2
/sbin/iwconfig wlan0 essid trekweb && \
/sbin/iwconfig wlan0 channel 4 && \
/sbin/iwconfig wlan0 mode Master
Thank you for any kind of comment or suggestions,