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Znarkus
Asked: 2012-09-23 04:43:30 +0800 CST

Can't get port forwarding to work on Ubuntu

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I'm using my server as NAT/router, which works well. But now I'm trying to forward port 3478, which I can't get to work.

eth0 = public interface
eth1 = private network

$ cat /proc/sys/net/ipv4/conf/eth0/forwarding
1
$ cat /proc/sys/net/ipv4/conf/eth1/forwarding
1

Then to forward port 3478 to 10.0.0.7, I read somewhere that I should run

iptables -t nat -A PREROUTING -p tcp -i eth0 --dport 3478 -j DNAT --to-destination 10.0.0.7:3478
iptables -A FORWARD -p tcp -d 10.0.0.7 --dport 3478 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT

I also ran

ufw allow 3478

But testing port 3478 with http://www.canyouseeme.org/ doesn't work. Any idea what I have done wrong?

ubuntu

1 Answers

  1. I use port forwarding (and working) on Ubuntu server with:

    #NAT:
-A PREROUTING -i eth0 -p tcp --dport 3478 -j DNAT --to 10.0.0.7

#FORWARD:
-A FORWARD -p tcp -i eth0 -d 10.0.0.7 --dport 3478 -j ACCEPT
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