Setting up to be a "router" using YDL?

[B McKee]

On Monday, October 4, 2004, at 10:33  PM, Dakidd wrote:

>
> Hiya folks...
> Now that I've figured out how to get the 7600/G3 running YDL 3.0.1 
> online
> directly via PPP and my dialup account, I'm looking to get the rest of 
> my
> local network (connected to the 7600 via Ethernet) online at the same 
> time
{snippage}
> Seems *PRETTY* straightforward - Configure/fire up the DCHP daemon on 
> the
> 7600, set everybody else up to get their network info via DHCP over the
> ethernet wire, and >poof< everybody's online at once! Wow... Magic! :)
{snippage}
> But it seems there's a catch: like most, my dialup assigns a dynamic 
> IP.
{snippage}
> 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.
>
The missing piece is NAT (Network Address Translation)
See the "NAT HowTO" at
http://www.netfilter.org/documentation/index.html#documentation-howto

Short answer is probably put this in rc.d/local...
(untested)
  modprobe iptable_nat
  iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
  echo 1 > /proc/sys/net/ipv4/ip_forward

But the doc in question will explain *what* it's doing as well as how 
to do it.

Brian