>> I need to NAT the internal network, being able to choose which IPs go
>> "nated" for the ADSL or for the leased line. The company's Directors
already
>> asked me to return to Linux, since it has "ip advanced routing". I'm
struggling
>
>First off, Linux doesn't contain any "avanced IP routing", in fact, Linux
>is complete trash and you'd be crazy to re-install it.

Yessss, I just love this kind of well argumented sentences.



For the source routing problem, you can tune ipnat.conf
It is okay for small netwoks. Big ones are ok too if you have some
separate adresses pool   i.e.  192.168.1.0/24  and   192.168.2.0/24