Why is this iptables rule that does port forwarding not working?
- by videoguy
I have a server bound to localhost:7060. It is using ipv6 socket instead of ipv4. Below is netstat outout.
# netstat -an
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 10.200.32.98:1720 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:4122 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:4123 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:4123 127.0.0.1:43051 ESTABLISHED
tcp 0 0 10.200.32.98:5555 10.200.32.44:53162 ESTABLISHED
tcp6 0 0 :::5060 :::* LISTEN
tcp6 0 0 ::ffff:127.0.0.1:7060 :::* LISTEN
tcp6 0 0 :::23 :::* LISTEN
tcp6 0 0 ::ffff:10.200.32.98:23 ::ffff:10.200.32.142:43505 ESTABLISHED
tcp6 0 0 ::ffff:127.0.0.1:43051 ::ffff:127.0.0.1:4123 ESTABLISHED
tcp6 0 0 ::ffff:10.200.32.98:23 ::ffff:10.200.32.44:53195 ESTABLISHED
udp6 0 0 :::5060 :::* CLOSE
#
I want to setup a port forwarding rule that accepts connections on port 24 (on all interfaces loopback as well as eth0) and forward the data to localhost:7060.
This is how I am setting up the iptables rule:
iptables -t nat -A PREROUTING -p tcp --dport 24 -j DNAT --to 127.0.0.1:7060**
It is not working. When I telnet from different box, I see the following
$telnet 10.200.32.98 24
Trying 10.200.32.98...
If I change the server to bind to *:7060 and set the following rule, it seems to work fine.
iptables -t nat -A PREROUTING -p tcp --dport 24 -j REDIRECT --to-port 7060
But that will make my server available on WAN interface which I don't like.
I feel it had something to do with ipv6 socket (tcp6 line in netstat output). This whole thing is done on an Android device with custom built Android platform image.
How do I get this working?
