[NBLUG/talk] iptables guidance/guru?

[Tim C. Lewis]

On Mon, 12 Feb 2007, Glen Gunsalus wrote:
> However, the default iptables set up by S35firewall (and probably the natting)
> doesn't let me pass traffic between the subnets.

could it just be that ip forwarding isn't enabled?
do: cat /proc/sys/net/ipv4/ip_forward;
output should be 1, not 0.  if 0:
echo 1 > /proc/sys/net/ipv4/ip_forward;
and/or add "net.ipv4.ip_forward = 1" to /etc/sysctl.conf and run
sysctl -p /etc/sysctl.conf

that's the first thing that comes to mind.  dunno what the default setting 
for openwrt is.


> Is there a sane way to get where I want w/o having to master iptables ((looks
> rather formidable to me at this point after looking at e tutorials).

sure, but it always helps to know what each rule is doing.  could always 
test with no firewall rules before adding them -- stop the firewall 
service, see if traffic routes under those circumstances before moving 
forward with drop/deny rules.

-tcl.