Create a Wired-Wireless bridge
 

Hi,

I have very poor wireless access in my room - I can connect only with an USB-wifi-stick - but multiple network devices (printer, notebook, PC). In order to be able to access the network with all of those, I linked them via ethernet and set up a network bridge between wired (connected to the devices in my room) and wireless (connected to my AP) network on the PC (Windows XP), which was working fine. But in this setup, the network printer is only available from the other parts of the network if the (loud) PC is running, so I wanted to run the bridge on an old but very quiet PC using Ubuntu on a Flash drive.

After some frustration that brctl won't let me add my wireless card to a bridge, I found out that bridging a wireless card in client mode is simply not supported because the specification does not allow the card to send packets from multiple MAC-addresses.

I'd accept this and would say "Just doesn't work", but as I said exactly the same setup is working under Windows XP by just right-clicking on the interfaces and adding them to a bridge. So is there any way to bypass the restriction in linux? And does anyone know if Windows take precautions to ensure compliance with the standard or if it just works out of luck?

Add 802.11 NIC to bridge device?
 

schigger,
You could add the USB wireless NIC to a bond device and add the bond to a bridge. Of course you have to modprobe the bonding driver. I infer that you already have bridge-utils installed.

ifcfg-wlan0 would look like this:

ifcfg-bond0 would look like this:

You only have one slave in the bond device. It should still work.

ifcfg-br0 would look like this:

Flush your FORWARD chain and add this rule to it:

Save the firewall.

Add a route that gets you to your network through br0:

Create a route-br0 in /etc/sysconfig/network-scripts to make the route persistent:

Restart your network and check everything with "ifconfig -a", "brctl show", "netstat -nr" and "iptables -L".

Thanks for the idea, I did not know about bonding interfaces. But unfortunately, this doesn't work for me either. When the bridge device goes up, at first it seems do work: "iwconfig" shows that the wireless interface is connected, "dmesg" tells that wpa_supplicant has finished the WPA authentication and "brctl show" says that eth0 and bond1 are part of the bridge. But ping to the acces point does not work, and about 30 second later, dmesg shows this line:

and the wireless interface is down again.
Here is my /etc/network/interfaces file:

(bond0 and wlan0 are supposed to work as an wireless access point in my room later, when ethernet works)

As it seems, bonding also does not work with wireless interfaces (or at least my interface): when I disable everything that is related to bridging, bring wlan1 up and type
wlan1 disconnects. After removing it from the bond interface, everything works again:

/var/log/syslog: