IP Masquerade + VMware + pptp

[franck routier <f.routier@wanadoo.fr>]

Has anyone experienced configuring IP Masquerade with pptp and VMware ?

My situation is :

- Debian box running unstable and kernel 2.4.2
- VMware + Windows 98 host system configured host-only
- ADSL internet connexion using pptp protocol

I would like my Windows virtual machine to access the net.
What I can do now is :

ping linux from windows
ping windows from linux
access the internet from linux

I know I should use NAT to masquerade Windows access to the net, BUT I
didn't succeded in doing so...
My interfaces are :

eth0 : ethernet card connected to the ADSL modem
ppp0 : ppp connexion to my provider via pptp
vmnet1 : virtual net between linux and windows in VMware

I tried to figure out how iptables works, but I was not successful with my
tries...
Especially,

iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward

taken from iptables howto, didn't do it.

I tried firestarter, but with no more success (besides, I have noticed it
doesn't see my vmnet interfaces).

Thanks in advance...

Franck