> I would like to limit the global bandwidth wan->lan, lan->wan to
> 2048kbits/128kbits for all the computer on the lan.
>
> Is it possible or can I only limit the bandwidth per host ?

No problem at all! Just add two shaper rules that apply to the LAN
interface, one with source any/destination LAN subnet (2048 kbps) and one
with source LAN subnet/destination any (128 kbps). Use 'none' for the
mask, and you'll be all set.

Greets,

Manuel