Is it possible to implement port forwarding with two servers?

Question

linux

There is a router with telnet access, is it possible to set up port forwarding from two IP addresses to one and access from outside? Let's say if the first server does not use port 1000, then the second server can use it or set it, and thus it will be accessible from the outside.

Answer 1

The first problem is to replace TELNET with SSH. Because using telnet in 2014 is tantamount to writing your passwords on all the fences around the world.
The answer to the second question is yes, it is possible. Forward the right ports to the right servers and that's it. For example, you send port 10000 to the first IP, port 20000 to the second IP.

Answer 2

It really depends on the router model.
If there is a free OpenWRT / DD-WRT / Tomato / ... firmware for it, then sketching a crutch for such functionality will not be difficult.