Hi there! I need to map a external port to an different internal port number. This is the situation: My ISP does not allow incoming connection on Port 21. I have got a new NAS which also has a FTP Server on Port 21 and you cant change the Port number. So if I input ftp://www.myftp.dyndns.org:1234 the following rule should exist: incoming data @ Port 1234 -> 192.168.1.103 @ Port 21 In the Webinterface a can only apply the rule if both ports are the same. In my internal network I am able to connect to the ftp server (21) but from outside it is not working because of my ISP Thx in advance!
And you have tried port triggering, can you not enter start and end range as the same the forward range as 21? then try adding a port forward entry perhaps?
What firmware are you running? Also, what revision is your router? I suggest running Thibors HyperWRT v15c or DD-WRT v23 SP1. Both will allow you to forward and map ports. www.linksysinfo.co.uk/thibor/ www.dd-wrt.com (the generic micro version can now be flashed to the v5)