ipfw ruleset question

[Andrzej Kwiatkowski]

> Sounds like your spam-blocking rules include some packet-accepting
> rules.  What does the ruleset look like?
>
100 divert natd all from any to any via ext_if

rules from 150 to 500 are blocking rules for my firewall

rules from 1000 and up are for  my clients.

My natd runs as 1:1 nat.

what I need is:

rules from 100 to 499 for blocking spam

500 divert natd all from any to any via ext_if

and the rest is not important...

I would like not all packets sending to nat,
it some kind of disabling spam, and so on..

Have got any idea ?

Thanks in advance
Andrzej Kwiatkowski