[CentOS] PREROUTING - DNAT with iptables for an ASTERISK BOX

Hi,

I am running a ASTERISK BOX behind a firewall. It is at DMZ .

Now I want to connect to my ASTERISK BOX from Internet. So I want to DNAT. How can I do it?

Pls assume that ip address that connects to Internet on firewall is 1.2.3.4and is attached to eth0. And ASTERISK BOX is 192.168.101.23

Then, What is the rule (PREROUTING) for it? What is the port to DNAT?

I think udp 5060. So I have added below 2 rules . But it does not work at all.

iptables -t nat -A PREROUTING -p udp -i eth0 -d 1.2.3.4 --dport 5060 -j DNAT --to-destination 192.168.101.23:5060 iptables -A FORWARD -p udp -d 192.168.101.23 --dport 5060 -j ACCEPT

Can you help me to solve this issue?