[SOLVED] Using NAT to forward incoming FTP to a spesifed IP

ARKSLACKBOX · 04-28-2016, 09:18 AM

I added the following two lines in my rc.firewall script to open for incoming FTP to a NAS box on the inside.

The lines:

iptables -t nat -A PREROUTING -p tcp --dport 21 -i <eth0> -j DNAT --to-destination <destination-IP>
iptables -t nat -A PREROUTING -p tcp --dport 20 -i <eth0> -j DNAT --to-destination <destination-IP>

unfortunately aftre reboot my internet didn't work. Can smoebody give me a clue what I did wrong?

smallpond · 04-28-2016, 04:11 PM

Did it come back when you removed the two lines?

ARKSLACKBOX · 04-29-2016, 02:33 AM

Hi smallpond,
Yes when I removed the two lines the internet started to work again. I discovered what was the problem. Earlier in the script I had made a rule that was in conflict with thees two new lines. It was actually a rule that blocked all inbound traffic. I corrected this and now it is working the internet and the ftp forwarding.

Thank you for your help.

ARK.