IP masq / forw / chain ?

[Vardhan Varma <vardhan.v@xxxxxxxxxxxxxx>]

 Hello ,
	I've been trying to setup some transparent way 
to connect my office lan using a linux machine to a 
ISDN dial up.

	The linux has eth1 ( lan ) and eth0 ( ISDN ).
kernel is 2.2.19, on debian 2.2r2. proxy on squid is 
running fine ( i.e. the gateway,route etc are all okay).

	Now i'm trying to enable NAT(or ip masq), and there 
are so many options in menuconfig, that i'm very confused. 
What i need is, if on my desktop, i set the gateway to 
linux's eth1's IP, than without any additional setting my
'telnet rest-of-world.com anyport' should work. also 
'telnet eth1-IP anyport'
should take me inside my own machine. I tried some things
but one of these were not working.

	What minimum do i need to set in menuconfig ?

TIA,
--Vardhan