[SOLVED] How to port-foward an external device plugged into an ethernet adaptor to another ethernet adaptor?

[andre_luis]

I'm replicating here a question I made in another place supposedly more specialized in this subject, however without return.

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I have a camera device working as a webserver with a local IP/Port 192.168.0.250:80 over the HTTP protocol, which is connected to one ethernet adaptor of the PC having the IP 192.168.0.1 and Gateway 10.20.30.10 and I wanted to access this camera remotelly throught another ethernet adaptor from the LAN where this PC is connected with IP 10.20.30.40 and gateway 10.20.30.10.

In short, I wanted to access this camera remotelly, mapped as the url http://10.20.30.40:8008.
( I already access this camera from local network with the url http://192.168.0.250:80 ) .

According to the following diagram, I have tryed some options to portfoward:

The first attempt was by mapping the camera connected to the 1st ethernet adaptor directly to the 2nd ethernet adaptor connected to the external network:

REM Route from Camera to Remote
netsh interface portproxy add v4tov4 listenaddress=192.168.0.250 listenport=80 connectaddress=10.20.30.40 connectport=8008

However, seemed too simple, and not surprisingly didn't work. Then, I tryed to implement an internal intermediary route, so that the external device would be mapped into an internal Port from one adaptor to another one:

REM Route from Camera to PC
netsh interface portproxy add v4tov4 listenaddress=192.168.0.250 listenport=80 connectaddress=192.168.0.1 connectport=1001
REM Route from PC to Remote
netsh interface portproxy add v4tov4 listenaddress=192.168.0.1 listenport=1001 connectaddress=10.20.30.40 connectport=8008

Didn't work, and finally tryed to route the camera throught the gateway, also with the intermediary approach, with no success aswell:

REM Route from Camera to PC
netsh interface portproxy add v4tov4 listenaddress=192.168.0.250 listenport=80 connectaddress=10.20.30.10 connectport=1001
REM Route from PC to Remote
netsh interface portproxy add v4tov4 listenaddress=10.20.30.10 listenport=1001 connectaddress=10.20.30.40 connectport=8008

What am I'm missing here?

Side notes:
1 ) Most Portfowarding tutorials explains how to map from localhost, not from external devices.
2 ) It is not intended to foward streamming video, instead, just to take sparse snapshots upon request, via URL sentences.

 

[FvM]

I believe you are setting up portproxy the wrong way. You want to create a listenport 10.20.30.40:8008 on the PC and forward it to 192.168.0.250.

 

[andre_luis]

I believe you are setting up portproxy the wrong way. You want to create a listenport 10.20.30.40:8008 on the PC and forward it to 192.168.0.250.

Although I could not find anywhere some tutorial depicting unequivocally e.g with illustration what is the local and the remote address, most explais with almost the same description:

listenaddress – is a local IP address to listen for incoming connection
listenport – local listening TCP port number (the connection is waiting on)
connectaddress – is a local or remote IP address to which we want to redirect incoming connection
connectport – is a TCP port to which the connection from listen port is forwarded to.

Once 10.20.30.40 is the remote address to which I want to redirect incomming conections and 192.168.0.250 is the local one where webserver listens for incomming connections, I fear it is not exactly as you said, or am I missing something?

--- Updated Jun 1, 2022 ---

I've just reversed the arrows direction at original picture in order to avoid misunderstanding from where server is indeed at.

 

[FvM]

I may misunderstand the descrption, but I see wrong direction arrows in your diagram. The real telation is this: The PC is exposing a proxy server at 10.20.30.40:8080, incoming client requests are redirected to 192.168.0.250:80.

 

[andre_luis]

It worked perfectly after correcting as your initial observation, in fact I had mislead what should be the listener and what to connect.
Just to share, here's the correct command line that worked:

netsh interface portproxy add v4tov4 listenaddress=10.20.30.40 listenport=8008 connectaddress=192.168.0.250 connectport=80