HOWTO Reroute incoming traffic to port 22 of a Linux box in a Windows network

[Pascal Vercammen]

Howto configure rerouting incoming outbound traffic to a
Linux box on the LAN using port 22 of that Linux box ?
The network architecture is as follows :
ADSL router => Windows2000 DMZ (server) (2 NICs) =>
switch : LAN

Somebody needs to connect to a Linux box socket
192.168.2.125 : 22. The router has a LAN address
192.168.1.1 The DMZ LAN interface has an IP address =
192.168.1.2 Its internal LAN interface uses 192.168.2.2
The target machine = 192.168.2.125:22
The WAN address = 80.201.246.213

Only following ports are open on the router : 20, 21, 25,
80, 110, 3389, 1723 and we do not have rights to open
additional ports.

I've added an address/port mapping on the NAT public
interface as follows : incoming/public port 20 ; private
IP = 192.168.2.125 ; outgoing/private port 22

However I cannot connect using a telnet session :
80.201.246.213 20

Therefore I started the FTP server (port 80.201.246.213
21) and reconfigured the address/port mapping for test
purposes as follows : incoming/public port 20 ; private IP
= 192.168.2.2 ; outgoing/private port 21

But there is no connection possible using telnet.
Directly connecting to 80.201.246.213 21 does not pose a
single problem.

 

[Herb Martin]

If you are using NAT or ICS on the Win2000 box just go into
the configuration and setup "special port mapping" from the
external port to the internal address/port (which just happens to be
Linux.)