I too would love to know this.  I have tried everything I can think of, 
and at this time believe it is not possible.  The only thing I have been 
able to do is change the scope of what the IPSEC tunnel will be allowed 
to access as far as IP range.  Would love to be able to build firewall 
like rules for the VPN tunnels.

Jukka Salmi wrote:

>Hi,
>
>I just used m0n0wall for the first time. It's extremely well done,
>congratulations!
>
>I set up some IPsec VPNs, they work fine. But I didn't manage to
>filter the VPN traffic. Is this possible at all? If yes, an example
>rule would be nice.
>
>
>TIA, Jukka
>
>  
>