Re: Port Forwarding only works outside?

[Sander Sneekes <sander@dmdsecure.com>]

try 

iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j MASQUERADE
iptables -A FORWARD -p tcp --dport 25 -d 192.168.1.29 -j ACCEPT
iptables -A PREROUTING -t nat -p tcp --dport 25 -d x.x.x.x -j DNAT --to
192.168.1.29

x.x.x.x = eth0 external ip

On Tue, 2002-12-10 at 16:31, Todd Hartman wrote:
> I've come across an issue I just don't know how to solve. I'm not even
> certain it's an issue with iptables itself, but I thought that someone
> here might have run across this before and have some advice.
>  
> I've got a RH7.3 box set up with two NICs. Eth0 is external and eth1
> is internal. Internal network is 192.168.1.* with netmask
> 255.255.255.128. I need to forward traffic on eth0, port 25 to
> 192.168.1.29. The firewall is 192.168.1.1 - both in the same subnet as
> I understand it.
>  
> When I forward SMTP traffic to 192.168.1.29 and try to telnet to port
> 25 to test SMTP, it just sits there, unresponsive. BUT, if I forward
> eth0 port 25 traffic to a machine out on the internet, it works just
> fine.
>  
> I suspect a networking problem, but I don't know well enough to pin it
> down myself.
>  
> -T
>