How to Port Forward When Mapped To Different Local Port

[nolehce 3]

I connect to AirVPN via Tomato Router. I have set iptables as per the how-to at this link:

https://airvpn.org/topic/9270-how-to-forward-ports-in-dd-wrt-tomato-with-iptables/?hl=%2Biptables+%2Bprerouting+%2Btun11+--dpor

 

It works fine if I am forwarding the same external to internal port. But what about when I want to re-map to a different internal port, do I put the internal port into iptables, or the external port, or both?

 

And how about for software firewalls further downstream on computers on my LAN... do I set the firewalls to allow the internal port, external port or both?

 

Thanks!!

[Mcavity 0]

same question..

on the airvpn web site i forwarded a port say 45000 to local port 9091

does that mean in iptables I use port 9091 as per this example?

 

iptables -I FORWARD -i tun1 -p udp -d x.x.x.x --dport 9091 -j ACCEPT

iptables -I FORWARD -i tun1 -p tcp -d x.x.x.x --dport 9091 -j ACCEPT

iptables -t nat -I PREROUTING -i tun1 -p tcp --dport 9091 -j DNAT --to-destination x.x.x.x

iptables -t nat -I PREROUTING -i tun1 -p udp --dport 9091 -j DNAT --to-destination x.x.x.x

 

x= my local server ip. 

[zhang888 1066]

 

same question..

on the airvpn web site i forwarded a port say 45000 to local port 9091

does that mean in iptables I use port 9091 as per this example?

 

iptables -I FORWARD -i tun1 -p udp -d x.x.x.x --dport 9091 -j ACCEPT

iptables -I FORWARD -i tun1 -p tcp -d x.x.x.x --dport 9091 -j ACCEPT

iptables -t nat -I PREROUTING -i tun1 -p tcp --dport 9091 -j DNAT --to-destination x.x.x.x

iptables -t nat -I PREROUTING -i tun1 -p udp --dport 9091 -j DNAT --to-destination x.x.x.x

 

x= my local server ip. 

 

More like

 

iptables -I FORWARD -i tun1 -p udp -d x.x.x.x --dport 45000 -j ACCEPT

iptables -I FORWARD -i tun1 -p tcp -d x.x.x.x --dport 45000 -j ACCEPT

iptables -t nat -I PREROUTING -i tun1 -p tcp --dport 45000 -j DNAT --to-destination x.x.x.x:9091

iptables -t nat -I PREROUTING -i tun1 -p udp --dport 45000 -j DNAT --to-destination x.x.x.x:9091