Re: bridge firewall with kernel 2.4.22

[Répási Tibor <repasi.tibor@chello.hu>]

Hy,

bridging is not routing! A bridge forwards frames at leyer 2, a router 
forwards ip packets at leyer 3.
However iptables is a 3rd leyer firewall, therefore bridged traffic is 
not affected by any iptables rule!

Francisco Oliveira wrote:

> hi
>
> I have compiled kernel 2.4.22 for bridge and iptables support.
>
> Bridge is working ok but Layer 3 packets are only processed if they 
> are addressed to bridge box ip address interface.
>
>  
>
> example
>
> hostA 
> --------------Bridgebox-------------------------Router------------Remote 
> locations
>
>  
>
> hostA ip address 10.13.0.1
>
> BridgeBox ip addres 10.13.0.2
>
> Router ip address 10.13.0.3
>
> Remote locations ip addres Any
>
>  
>
> If I write a rule into the bridgebox to deny all forwarding traffic 
> for Any destination, and  router ip addres as hostA default gateway. 
> Packets are not processed by bridge box and are routed by router 
In this case packets are bridged by the bridgebox (at leyer 2) an routed 
by the router.

>  
>
> If the same rule is written with bridge box as hostA default gateway 
> works ok
Here the ip packet is goind through the 3rd leyer of the bridgebox (are 
routed by it) and iptables rules are processed.

> I would like bridegebox process all ip traffic throught it
Exclude the interface ot the router from the bridge.


Best regards,
   Tibor Repasi