Securityhome.eu

Posted: **Fri Dec 02, 2016 6:40 pm**

Hi,

I setup a linux router,
it has nat-gateway and is working perfectly.

Except the port forwarding from the internet to the local network.
I think i did everything ok.

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echo 1 > /proc/sys/net/ipv4/ip/forward

iptables -A PREROUTING -i eth0 -p tcp --dport 80 -j DNAT --to 192.168.1.2:8080

When i test the connection from the outside,
it just time out.

Posted: **Fri Dec 02, 2016 8:01 pm**

I think you forgot the actual forwarding.
Check it with:

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iptables -L

For you particual case:

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iptables -A FORWARD -p tcp -d 192.168.1.2 --dport 8080 -j ACCEPT

The next schema makes it clear:

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PACKET IN
    |
PREROUTING--[routing]-->--FORWARD-->--POSTROUTING-->--OUT
 - nat (dst)   |           - filter      - nat (src)
               |                            |
               |                            |
              INPUT                       OUTPUT
              - filter                    - nat (dst)
               |                          - filter
               |                            |
               `----->-----[app]----->------'

It comes from the site:
http://www.systutorials.com/816/port-fo ... -iptables/

Posted: **Mon Dec 05, 2016 9:44 pm**

Yep, that was my mistake.

The standard forward policy was set to drop,
and only related and established connections.

Setting the prerouting is not enough,
I also need to set the forward.

Thanks,
the little schema made it clear

Securityhome.eu

SOLVED: Port forwarding doesn't work

SOLVED: Port forwarding doesn't work

Re: Port forwarding doesn't work

Re: Port forwarding doesn't work