In "ipfilter for LAN<->Net link.", Dan Jacobowitz <dan@west.chwest.org>
wrote: 
> 
> Is anyone using this?  I have looked at the ipfilter web pages and am
> unsure as to whether it will do what I want...link multiple machines
> through one IP address using NAT.  Any advice?
> 

Yes, it works fine.  Look at the example NAT rule they show, and be
sure to use 'ipnat' to do the configuration.

You need two interfaces in your machine as well, but I'm assuming you
have an ethernet and a serial (ppp) interface, so that's not a problem.
Basically just give all your 'other' machines, and the ethernet interface
an non-routed IP address, and then setup a NAT rule to translate everything
from the ethernet interface to the 'real' IP address used on the
serial interface.  Ta-da.

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