Setting up to be a "router" using YDL?

[Longman, Bill]

<snip>
> But it seems there's a catch: like most, my dialup assigns a 
> dynamic IP.
> So setting up the 7600 to act as DHCP server seems to have a 
> fatal flaw
> even before I begin. Or perhaps I'm too green in the *nix world to
> understand how things work?

If you have only a few machines on the inside, do you really need DHCP? It's
probably easier to just static them, then you don't have to monkey with DHCP
at all. Just set the 7600 as the default gateway on all the machines.
 
> Over in "Mac-land", it takes something like VicomSoft's "Softrouter",
> "Surfdoubler", or similar, to get the Macs talking to the 
> internet via the
> "master" machine - more or less a "create two networks with a 
> wall between
> them" situation - the one on "my side" of the "wall" being 
> one (probably
> using the 10.1.x.x or 192.168.x.x non-routed spaces) and the 
> other being
> "just" the modem and 7600, with a 204.?.?.? address - The 10.1/192.168
> machines talk to the 7600, which "shows" them a fixed 10.1.x.x or
> 192.168.x.x address, and deals with the voodoo of shipping 
> their traffic
> (either inbound or outbound) "over the wall" to the "real" internet as
> needed, while at the same time, showing the "real" internet 
> its 204.x.x.x
> address.
> 
> I know how to create (using PPP) the "internet" side of the 
> wall, and I
> have a pretty good idea of how to deal with the "local" side, 
> but trying to
> get something/somebody to "go over the wall" (either way) 
> with packets in
> hand is eluding me.

You need to look at masquerading. It's very simple and there are heaps of
firewall/masq utilities out there to help you. Google around and you'll find
lots. There's probably a fair bit on the FAQ, too. You, of course, have
already looked there. That goes without saying.
 
> I get this far, and my head starts spinning...
> What am I missing? Anybody feel like helping me stop the rotation?
> 
> And is this question even appropriate for this list? If not, 
> where would be
> better?

This be the place, baby! Come on back with more questions and what you've
found. We'll get you there. And for free!