how to stop masq

I am using e-smith 5.6 in gateway mode, and need to disable
masquarading. I tried simply stopping the masq service.
That just shut down the internet connection. Are there anybody
who knows how to disable NAT, and instead just let the box
relay in- and outgoing packets without touching them, such that
the rest of the network stay connected to the net through the box.

I don't need my firewall either, so if anybody knows how to get rid of
that, it would be great (Both things are handled in hardware by my
router, but for other reasons I need to have the e-smith between my I-net
and the rest of the network)

Thanks in advance,

Troels Haugboelle