WOL to different interfaces

[TrialAndError]

Hi,

i have got machines on different subnets. Everything (except WOL) works perfectly over my router (ipfire).

Therefore I directly connected the FOG server to the second subnet with a second interface: still no WOL on the second subnet.
Then I activated and installed the plugin wolbroadcast: still no WOL on the second subnet (broadcast address configured in /etc/network/interfaces).

Any Tips? Help is appriciated.