I guess the following will be considred a hack, but here goes:
I have machines A and B, and C.
B can open a connection to A, but A cannot open a connection to B (due to FW).
Work: A <--- B
Doesn't work: A ---> B
I want to be able to open a connection from A to B.
Is there a way (tool, preferably an OS tool) to allow a seamless connection initiation from A to B, quite possibly by tunneling on top of an existing connection from B to A?
At the end of the day I want to be able to successfully telnet from A to B:
telnet B [port number]
Or even to machine C, that B has access to, but A doesn't. From A:
telnet C [port number]
I've been offered with "static" tunneling. But, I would to have seamless solution.
For example, configure that a connection attempt to a certain range of destination IPs will be tunneled through B, where C is the dynamically varying destination. So telnet 80, will connect to the target passing through B