iptables port forwarding

[sdousley]

ok, the situation.

i have the following scenario:

-----------
|internet |
-----------
|
|
|
------------
|Cablemodem|
------------
|
|
|
|Blueyonder DHCP Assigned{eth1:}
------------
| gateway |
------------
|192.168.0.1{eth0}
|
|
------------
| switch |
------------
| | |
| | |
| | |192.168.0.9{eth0:}
X X --------------
| workstation|
--------------
|
|
|USB webcam {/dev/video0}

now, i have setup an application called palantir that allows me to stream my webcam to the internet, and it uses port 3000, now what i need to do is forward requests on eth1, port 3000 of the gateway to my computer, how do i set this up using iptables?

Hope the diagram helps in what i need to do.

[swemic]

It should be something like this

iptables -A PREROUTING -i eth1 -p tcp -m tcp --dport 3000 -j DNAT --to-destination 192.168.1.9:3000
iptables -A INPUT -i eth1 -p tcp -m tcp --dport 3000 -j ACCEPT

[sdousley]

It should be something like this

iptables -A PREROUTING -i eth1 -p tcp -m tcp --dport 3000 -j DNAT --to-destination 192.168.1.9:3000
iptables -A INPUT -i eth1 -p tcp -m tcp --dport 3000 -j ACCEPT

ok, the first line gives an error:

jebediah:~ # iptables -A PREROUTING -i eth1 -p tcp -m tcp --dport 3000 -j DNAT --to-destination 192.168.0.9:3000
iptables: No chain/target/match by that name

[EviLsock]

iptables -t nat -A PREROUTING -i eth1 -p tcp -m tcp --dport 3000 -j DNAT --to-destination 192.168.1.9:3000
iptables -A INPUT -i eth1 -p tcp -m tcp --dport 3000 -j ACCEPT


add -t nat

[swemic]

Yeah, I forgot that "-t nat" *sorry about that*