# [Solved/Workaround] Configuring a Proxy wlan0 <-> eth0

## r3tep

Hi,

I have the following setup:

this system -> wlan0 192.168.1.2 <-> router 192.168.1.1 <-> internet

this system -> eth0 192.168.2.1 <-> some other systems

wlan0 goes up on booting. 

eth0 manually.

The other systems does currently not have any direct access to the internet. I would like to let my system act as proxy.

I read somewhere about the possibility configuring a bridged interface br0=wlan0<->eth0. Is it possible, to use wlan0 and br0 at the same time? In other words, can the bridging system and systems behind the bridge use internet at the same time?Last edited by r3tep on Tue Mar 09, 2010 7:17 am; edited 1 time in total

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## eccerr0r

The easiest way is to just let the system route/NAT to wlan0, which shouldn't be too difficult - just make the machine into a pseudo-router.

Yes, bridging is the other way, but I hear there are many caveats.  Because it's a bridge, the drivers for wlan0 and eth0 need to be able to forge the address of the packet on the other side of the bridge, and not all drivers support that... I think this was meant to be "WDS" mode for the wireless side, for wireless distribution system.  Barring that issue, supposedly you can link both interfaces to the same bridge just fine (that's how WRT54G's work sort of...except WRT54G's wlan0 are in master mode...

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## r3tep

I solved that problem yesterdey by using net-firewall/firehol to generate an iptables configuration.

Bridging was afaik on my setup not possible because of that two different networks.

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## eccerr0r

You could have put them all on the same network?  Is that acceptable?

This is sort of how the WRT54G works... wlan0 is actually separate from eth0.  In order for the wireless to be on the same subnet, it creates br0 which is the lan ip address.  eth0 and wlan0 (not real names, just using symbolics) are brctl'ed to br0.  They don't have IP addresses assigned to them, and the router has to copy packets to the other side of the bridge.

But anyway it sounds like the NAT solution works, just that they aren't on the same subnet.  At least it forces people to choose carefully what to be on what side of the router...

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