I have three network printers at our local office, all of which listen on port 9100. Non of them offer the option of changing the listening port. We have a single public static IP address, and access to our main network is through a Linksys WRT-54G.

We need to be able to print to these printers from outside the office. The problem is, with the 54G, I can only forward a port to the SAME port on a particular IP address. What I really need though is a way to forward to an ip address and a DIFFERENT port.

I need to do this:

In port    Destination
9100 : 9100
9101 : 9100
9102 : 9100

So I'm looking for options.

I could setup an old computer with two network cards and IPtables I suppose, but that seems like a lot of overhead for something relatively simple.

Is there a way a virtual machine (read: one network card) could do the advanced port forwarding? Where I forward all traffic to it, and it forwards it on to the right printer?

Or what about those mini Linux distros that replace the WRT-54G's firmware? Do any of those support what I need "out of the box"?

I have a spare WRT- could I make it an IP tables router? Recommendations for mini distros?

Or is there an off-the-shelf product that does this (cheap/local preferred)?

Any advice / options appreciated.



The WRT54GL with DD-WRT does support redirecting different public ports to the same internal port of different IPs. I would think the regular firmware does this too, are you sure?

  • +1 It has been ages since I have used the standard firmware but if I remember correctly it did not support forwarding to different port numbers. Firmware upgrade is probably required. May 14 '10 at 15:07
  • It does support redirecting an external port to the same internal port number, but I need to 'remap' the external port to a different internal port number.
    – Nick
    May 14 '10 at 15:11
  • I vaguely remember that being there but under a different tab or even section in the gui. May 14 '10 at 15:13
  • There's a section called "Port Triggering" that lets you forward one port to another, but it doesn't have an option for an ip address...
    – Nick
    May 14 '10 at 15:21
  • I installed dd-wrt over the default firmware and now have port mapping functionality. Thanks for your help!
    – Nick
    May 14 '10 at 22:56

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