LARTC - Apr 2005 - How can I block packet between eth0 and eth1?

Hello 

I am using linux box as a network loadbalance router.


                -----------------                               ------------
|LAN| - |eth0         eth1(1.1.1.2)  | DSL1 ------- |DSLAM (1.1.1.1) |
             |               eth2(1.1.1.10) | DSL2 ------- |DSLAM (1.1.1.9) |
                 ----------------                               ------------
                    
But I have a big problem.

If eth2(DSL2) line down,  but still on available ping eth2

Because of DSL from DSLAM has s layer 2 architecture.

So through eth1, eth2''s mac address is transferred.

I want block any packet between eth1 and eth2.

I tested local network, too.

Connected 2 cables on each LAN card from switch.

          
|LAN| --- |eth0  1.1.1.1  |
          --- |eth1  1.1.1.2  |
         

I removed cable(eth0), but I can use ping to 1.1.1.1 (because of response from
eth1)

How can solve this problem?

I did serverl times kernel compile change options, and configure /proc/net*


I want that.............
eth0 link up then I want use 1.1.1.1
eth1 link up then I want use 1.1.1.2
Both link up then I want use 1.1.1.1 or 1.1.1.2
but eth0 link down, eth1 link up then I want use only eth1 --> I want solve
this problem

Thank you for reading this.

Have a nice day


ps. sorry I am poor at english