Here's my dilemma in a nutshell: I have a Sun Sparc machine that collects data from several machines across the internet. The data is collected by UUCP over TCP. One of the machines is located somewhere where TCP port 540, the one that UUCP normally uses, is blocked somewhere at a router we don't control, so I have configured that machine to listen on another port. Let's call the IP address of this machine 1.2.3.4.
The problem arises that the collection machine, which instigates all the connections, expects UUCP over TCP to occur on port 540. What would be a very nice resolution is for me to be able to put a simple rule in ipfilter such that any outgoing packet with a destination of 1.2.3.4:540 would be remapped to the unique port being used by this one machine (let's say its 999), and any incoming packet from 1.2.3.4:999 would be remapped to make it appear as if it was from 1.2.3.4:540. I already have ipfilter loaded on the collection machine, but am currently using it only for filtering, not NAT. This is not really NAT in the traditional sense. For instance, there is no need to retain any connection-oriented history here. I have tried various flavors of the rule: rdr hme0 1.2.3.4/32 port 540 -> 1.2.3.4 port 999 tcp unfortunately, with no luck. I'm not even sure I am going about this in the right way. Is there a way to accomplish what I want with ipfilter, and if so how should one craft a rule to do it? As always, thanks in advance for your help and suggestions. Rob
