The web interface for the Actiontec dsl modem/router, has a limit of 20 entries, the o/s for the router is embedded linux, so, to add more port forwarding entries, the user would have to use telnet, these instructions below explain how to add more than 20 entries, bare in mind, that when the entries are added manually, any power outage will erase the entered values, it is best to make a list of ports that are being manually entered into the router.
1st, (if not already done so) using the web interface, create an admin user name and password, this is required for telnet access. Make a note of your routers ip address, (default 192.168.0.1) if changed.
close the web interface.
Assuming the routers ip address is 192.168.0.1.
Most windows come with telnet, click on 'START->RUN' type in '(CMD if using winxp), (command if using windows prior to xp)', press 'ENTER', then type 'telnet 192.168.0.1' (or whatever the router address is) then press 'ENTER' at the login prompt enter the admin user name for the router, then press 'ENTER' then enter the admin password for the router then press 'ENTER'.
Now for the crucial part, to find the computers lan ip address type 'ifconfig br0', press 'ENTER', make a note of the 'inet addr:' address, this is the routers address.
type the following command exactly as seen here including uppercase and lowercase:-
iptables -t nat -A PREROUTING -i ppp0 -p [protocol] --dport [port] -j DNAT --to [computer lan ip address]
replace [protocol] with either tcp or udp
replace [port] with the port or port range you want to forward e.g.. 21 to forward a single port or 21:25 to forward ports 21 through 25.
replace [computer lan ip address] with the ip address of the computer that you want to allow the port to be forwarded to, e.g... If there's 10 computers on the lan, and the lan ip addresses are 192.168.2.1.......192.168.2.10, and the computer that would have the ports 21 through to 30 using tcp protocol, forwarded to it, has the lan ip address of 192.168.2.7, then the command to use would be:-
iptables -t nat -A PREROUTING -i ppp0 -p tcp --dport 25:30 -j DNAT --to 192.168.2.7
When finished adding all the required ports, type 'EXIT' and press 'ENTER' to disconnect from the router and return to the command prompt, then type 'EXIT' then 'ENTER' to return to windows.
1st, (if not already done so) using the web interface, create an admin user name and password, this is required for telnet access. Make a note of your routers ip address, (default 192.168.0.1) if changed.
close the web interface.
Assuming the routers ip address is 192.168.0.1.
Most windows come with telnet, click on 'START->RUN' type in '(CMD if using winxp), (command if using windows prior to xp)', press 'ENTER', then type 'telnet 192.168.0.1' (or whatever the router address is) then press 'ENTER' at the login prompt enter the admin user name for the router, then press 'ENTER' then enter the admin password for the router then press 'ENTER'.
Now for the crucial part, to find the computers lan ip address type 'ifconfig br0', press 'ENTER', make a note of the 'inet addr:' address, this is the routers address.
type the following command exactly as seen here including uppercase and lowercase:-
iptables -t nat -A PREROUTING -i ppp0 -p [protocol] --dport [port] -j DNAT --to [computer lan ip address]
replace [protocol] with either tcp or udp
replace [port] with the port or port range you want to forward e.g.. 21 to forward a single port or 21:25 to forward ports 21 through 25.
replace [computer lan ip address] with the ip address of the computer that you want to allow the port to be forwarded to, e.g... If there's 10 computers on the lan, and the lan ip addresses are 192.168.2.1.......192.168.2.10, and the computer that would have the ports 21 through to 30 using tcp protocol, forwarded to it, has the lan ip address of 192.168.2.7, then the command to use would be:-
iptables -t nat -A PREROUTING -i ppp0 -p tcp --dport 25:30 -j DNAT --to 192.168.2.7
When finished adding all the required ports, type 'EXIT' and press 'ENTER' to disconnect from the router and return to the command prompt, then type 'EXIT' then 'ENTER' to return to windows.