RH9, NAT and routing

[Bob Smith]

Hi Pete,

Thanks for the rules, I think I see what I missed, which I believe is the
forwarding rule from the lan. 

I'd still like to check out firestarter, just to see what it does, and
learn yet another tool.  :-)  Is there a good place to find it?

Thanks,

-Bob

> Hi,
> I have a similar fw (but 3 nics). 
> here is the basic sequence of the pertinent rules from my fw to let LAN 
> traffic out. Depending on your comfort level, using firestarter may be 
> preferred. These are only a few of a complete set.

> # Default deny all inbound & forwards.
> # probably just allow all out, your discretion, but if you deny all outbound
> # you won't contribute to DD0S, just make last one DENY as well then
> # allow the desired services out.
> $IPTABLES -P INPUT DROP
> $IPTABLES -P FORWARD DROP
> $IPTABLES -P OUTPUT ACCEPT

> # outbound LAN connections are all masquaraded
> $IPTABLES -A POSTROUTING -t nat -o $EXT_IF -s $LAN_RANGE -j MASQUERADE

> # allow existing communications to continue
> $IPTABLES -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

> # forward 
> $IPTABLES -A FORWARD -i $LAN_IF -s $LAN_RANGE  -j ACCEPT
> $IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT

> # I end each section (input, forward, output) with log and drop, here the
> # forward set
> $IPTABLES -A FORWARD -m limit -j LOG --log-prefix "NetF FORWARD CHAIN: "
> $IPTABLES -A FORWARD -j DROP

> Of course, there should be other rules in place, but this should allow 
> successful outbound connections from your LAN. 

> Hope that helps.
> -- 
> Pete Nesbitt, rhce