[Click] Difference between ToHost and ToDevice??

[sendoa vaz]

Hello everybody,

I'm trying to communicate two etherswitches using two tap devices and a
linux bridge between them, as you can see in the following:

      Tap1---switch1----Tap0-------------Linux
Bridge-------------Tap2---Switch2-----Tap3

The config files are:

Switch1::EtherVlanSwitch(TIMEOUT 300)

FromHost(tap1)->[0]Switch1[0]->ToHost(tap1)
FromHost(tap0)->[1]Switch1[1]->ToHost(tap0)

Switch2::EtherVlanSwitch(TIMEOUT 300)

FromHost(tap2)->[0]Switch2[0]->ToHost(tap2)
FromHost(tap3)->[1]Switch2[1]->ToHost(tap3)

Using this configuration are forwarded correctly but the if I capture them
using wireshark the packet's fields seem to be moved. This is due to the 4
bytes addition in the ToHost element. The problem is that if I remove the 4
byte addition of the element ToHost I can capture the packet correctly but
the packets aren't forwarded through the bridge.

I have tried to use Queue->ToDevice() instead the toHost elements, but the
packets aren't forwarded (but I can capture them correctly with wireshark).

Anyone knows why could this happen? I think it must be something related
with the field ethertype of the packet, but I don't understand why we should
add anything to the packet in the element ToHost.

thanks in advance.

Sendoa