Packet Redirector on Server
I have the follow scenario:
There are two IP-Devices each behind an Internet router. One of the Internet Access Point has an dynamic IP, the other one is static.
These IP-Devices are not able to resolve URLs (do DNS stuff). So I have to enter an fixed IP-Address on each device to make it possible to find each other.
I was looking forward to solve the problem using an external Server (Ubuntu-Server 2.6.31-22) to redirect the packets. There are packets received on a specific PORT from an specific IP address. These packets on the one hand should be redirected to the static IP which does not seem to be a problem. But on the other hand the packets should be redirected to the dynamic IP Address which can be resolved by a dyndns-URL.
Most applications in forums try to use iptables, but as far as i know, the rules with dyndns-URLs in it are resolved when the iptables-rules are commited only once. After 8hrs the IP changes and the rule is not valid anymore. I do not want to reload the iptables all the time because this server is handling a lot of webservices which should not be interrupted.
Is there something like a tool which suppports this?