Requirements
============
I want to bridge a wired ethernet with an wireless LAN, where systems on both sides can communicate with each other.

Environment
===========
WLAN Access Point (AP#01): D-Link DWL-1000AP
IP: 10.10.10.88
Netmask: 255.255.224.0 (don’t ask me why, it’s due to history, and can’t be changed)

Ethernet/WLAN-Bridge (BR#01): Siemens Scenic Mobile 510 AGP notebook
OS: Debian GNU/Linux 3.0r1 Kernel 2.4.22
Hostname: sm510agp-bridge
eth0: D-Link DFE-660
IP: 192.168.0.250
Netmask: 255.255.255.0
Promiscious Mode
eth1: Lucent Orinoco Silver WaveLAN
IP: 10.10.10.79
Netmask: 255.255.224.0
Promiscious Mode

PC#01: NoName
OS: Win2k SP#3
Hostname: scrappy
eth0:
IP: 192.168.0.10
Netmask: 255.255.255.0
Default Gateway: 192.168.0.250

+-------+ +-------+ + + +-------+ /--------\
| PC#01 +-------+ BR#01 +-+ <<<>>> +-+ AP#01 +-----+ LAN#02 +
+-------+ +-------+ +-------+ \--------/
eth0 eth0 eth1

Approaches
==========
1. Ethernet Bridge
-------------------
Using default bridging features coming along with Linux, I had to learn that bridging a wired with a wireless LAN won’t work because of MAC address issues, and the Orinoco card can’t be operated using the HostAP driver. => DISMISS!

2. Proxy ARP/IP Bridge
-----------------------
Okay, IP Bridging or Proxy ARP seemed to be the solution; I got ‘iptools2’, I got ‘parprouted’, compiled and installed the software, configured everything accordingly, and....from BR#01 I could successfully do a ‘ping’ to the AP#01 and any system on LAN#02 and PC#01. When using PC#01 and trying the same, I can successfully ping both interfaces of BR#01, but not a single step further!

3. Router
----------
Hmm, approach 2 didn’t work, why not just configuring the Debian box as a router?

bash# route add -net 192.168.0.0 netmask 255.255.255.0 dev eth0
bash# route add -net 10.10.0.0 netmask 255.255.224.0 dev eth1

When trying this configuration the results are just the same as with approach 2.

From PC#01 I can’t go past the WLAN connection!

Why is this so? What happens? How can I solve this all, preferably using approach 2?

at a guess, I'd say the AP may not know how to get to the 192.168.0.0 network. You can try to see if there is any way to enter routes into the AP. Given that it is a D-Link, then I suspect not.

I'm not sure what you are trying to do (in the grand scheme of things), but you could try doing NATP on your bridge device so that any traffic from 192.168.0.0 to 10.10.10.0 will have a source address of 192.168.0.250. Of course this won't really work if you want full bi-directional connectivity unless you want to go and setup a whole stash of static NAT's.

Thanx!

In the meantime I solved this riddle, like:

Environment
===========

Any#01 Hub Linux Proprietary Hub Any#02
+-------+ /------\ +-------+| <<<>>> |+-------+ /------\ +-------+
| PC#01 +-----{ LAN#01 }-----+ BR#01 ++ ++ AP#01 +-----{ LAN#02 }-----+ PC#02 |
+-------+ \------/ +-------+ +-------+ \------/ +-------+
eth0 eth0 eth1 eth0 eth0
192.168.0.10 192.168.0.252 | 192.168.0.254 192.168.0.20
192.168.0.253

Netmask: 255.255.255.0

BR#01
=====
Software
--------
* Debian GNU/Linux 3.0p1 (my case)
* Kernel 2.4.22 (bridging enabled) (my case)
* Orinoco driver (orinoco_cs) => http://www.hpl.hp.com/personal/Jean_...x/Orinoco.html
* wireless tools 26 (iwconfig, etc.) => http://www.hpl.hp.com/personal/Jean_...nux/Tools.html
* iptools2 (ip, etc.) => ftp://ftp.inr.ac.ru/ip-routing/
* Proxy ARP/IP Bridge (parprouted) => http://freshmeat.net/projects/parprouted/

Configuration
-------------
1) /etc/network/interfaces

# all available interfaces
auto lo eth0 eth1

# The loopback interface
iface lo inet loopback

# The first network card (wired)
iface eth0 inet static
address 192.168.0.252
netmask 255.255.255.0

# The first network card (wireless)
iface eth1 inet static
address 192.168.0.253
netmask 255.255.255.0

2) /etc/init.d/ifdownup (executable; sym.link -> /etc/rc[2345].d/S30ifdownup)

/sbin/ifdown -a
sleep 2
/sbin/ifup -a
sleep 2

3) /etc/init.d/ipbridge (executeable; sym.link -> /etc/rc[2345].d/S30ipbridge)

/sbin/ifconfig eth0 0.0.0.0
/sbin/ifconfig eth1 0.0.0.0
/usr/local/sbin/parprouted eth1 eth0
echo “1” > /proc/sys/net/ipv4/ip_forward

4) /etc/init.d/routing (executeable; sym.link -> /etc/rc[2345].d/S30routing)

/sbin/route add -host 192.168.0.10 dev eth0
/sbin/route add -net 192.168.0.0 netmask 255.255.255.0 dev eth1