squeeze how to hot-reload new interfaces file

[Martin Seener <martin@seener.de>]

I think i may be discussed earlier but i didnt find it yet.

as all may know /etc/init.d/networking restart (or invoke-rc.d 
networking restart) didnt work anymore.

while trying to handle it with ifdown -a && ifup -a it doesnt work either.

we have a post-boot config like this

auto lo
....

auto eth0
iface eth0 inet dhcp

we want to migrate to

auto lo
....

auto bond0
iface bond0 inet static
.....

ifenslave-2.6 is already installed but when i change the interfaces file 
- how can i easily make the new config active without rebooting the 
whole server??

Thank you for any help!