CentOS - Aug 2010 - NAT via /etc/sysconfig/iptables

Hello listmates,

It's been a few years since I've set up a router... and for some
reason I seem to be getting hung up on this one.

Does anybody have a sample iptables config file that would incorporate
NAT and forwarding for a simple router?

Thanks.

Boris.

>Does anybody have a sample iptables config file that would incorporate
>NAT and forwarding for a simple router?
Turn on ip frwding in sysctl.conf:
net.ipv4.ip_forward = 1

Then rules something like this (Tune for your needs):
# Accept packets belonging to established and related connections
/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Setup masquerading on WAN interface & forward specified requests
/sbin/iptables -A POSTROUTING -t nat -o $WAN -j MASQUERADE
/sbin/iptables -A FORWARD -i $LAN -o $WAN -m state --state
NEW,ESTABLISHED,RELATED -p tcp -m multiport --dports 80,443 -j ACCEPT
/sbin/iptables -A FORWARD -i $WAN -o $LAN -m state --state RELATED,ESTABLISHED
-j ACCEPT


Have a quick read on:
http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables

On Mon, Aug 2, 2010 at 1:45 PM, Boris Epstein <borepstein at gmail.com>
wrote:
> Hello listmates,
>
> It's been a few years since I've set up a router... and for some
> reason I seem to be getting hung up on this one.
>
> Does anybody have a sample iptables config file that would incorporate
> NAT and forwarding for a simple router?
I found project quicktables very helpful
(http://freshmeat.net/projects/quicktables).

-- 
Eduardo Grosclaude
Universidad Nacional del Comahue
Neuquen, Argentina