Using the ubuntu server as an intermediary, I forwarded port 80 to its port 3355 from windows, on the ubuntu server using the command
links2 127.0.0.1:3355 A website with a Windows server (with a gray IP) is forwarded and successfully displayed. Trying to access the address from the external machine (external Ubuntu server), the site does not open. Forwarding is done through the Putty (callback) ssh tunnel.
Once again I will try to explain, apparently I am very misinterpreted .. On machine 1 IIS is up, Putty is running on it and a tunnel is created to the Ubuntu server 
On ubuntu server, when accessing 0.0.0.0天325


*.*.*.*Or IP of the machine (the network with which access will be given). - nick_n_a127.0.0.1is a localhost, it is always not accessible from the outside. Write another address there. - nick_n_a127.0.0.1to0.0.0.0. - Qwertiy ♦