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javasocketsnattunneling

Port Forwarding

I have a simple requirement of a software level port forwarding/tunnelling of socket based communication.

  • I have a source server and port using Sockets. This is a java program which works both in windows and linux and this is irrelevant.
  • I have devices which keep sending data to this port. There may be a bi-directional communication
  • I want to redirect this data to another remote server and port. So for the clients they will not have to worry about change of ip address whenever I move my app server.

Are there any tools/deamon/service programs which I can use to configure and do this?

I tried SSH, but to my understanding this needs a SSH protocol enabled server. In my case this is not applicable. I also tried using JSch but this again is an implementation of SSH in java format.

Can someone throw some pointers? Is it possible to use iptables NAT in linux?

Solution

  • You can try netcat or socat (it's more powerful than netcat)

    An example for socat to forward port 80 using tcp4:

    socat tcp4-listen:80,fork tcp4:{another server}:{another port}

    and refer to http://en.wikipedia.org/wiki/Netcat#Port_Forwarding_or_Port_Mapping for netcat

    Both are not java-related.