Strange Bridge Issues

[Karim Fodil-Lemelin]

Hi,

    I have applied Luigi's patch to a FBSD 4.8 kernel to be able to use 
fwd rules in ipfw with a BRIDGE. I have to say its a very cool feature. 
Now, there is two side of this, one good and one that I really need to fix.

    The good side is it works in this configuration:

    CLIENT --------(fxp0) BRIDGE1 (fxp1) --------- ROUTER(S) 
-----------(fxp1) BRIDGE2 (fxp0) ------- SERVER

    CL:IENT is on the same subnet as BRIDGE1 and SERVER is on the same 
subnet as BRIDGE2, using ipfw rules like this:

    reset tcp from any to me XXXX
    reset tcp from any to me YYYY
    fwd 127.0.0.1,XXXX tcp from any to any in via fxp0
    fwd 127.0.0.1,YYYY tcp from any to any in via fxp1

    I get all tcp traffic to be  "sucked in" by the fwd rules to a proxy 
application that goes out to connect from fxp1 (fxp1 has an address for 
the proxy to bind on). It is then grabbed by another proxy on BRIDGE2 
and forwarded to another proxy on port YYYY and it connects to the 
SERVER just fine.

    There is only one route, which is default pointing to the closest 
ROUTER on both bridge.

    The previous scenario work just fine but if it gets more 
complicated, with something like this:

    CLIENT ----- ROUTER(S) -----  BRIDGE1 ----- ROUTER(S) ---- BRIDGE2 
----ROUTER(S) ---- SERVER

    Here, CLIENT is _not_ on the same subnet as BRIDGE1 and SERVER is 
_not_ on the same subnet as BRIDGE2.

    Using the same rules as above, traffic comming from CLIENT goes 
through the BRIDGE1 _whitout_ being "fwded"!!

    If anyone could help me to figure at least why tcp packets are going 
through whitout being sucked in, I would really appreciate.
    Obviously if you know how to fix this then please let me know :).

Regards,

Karim.